1.
Red Wine (film)
–
Red Wine is a 2013 Malayalam-language Indian nonlinear investigation thriller film directed by Salam Bappu, and starring Mohanlal, Fahad Fazil, and Asif Ali in lead roles. The films soundtrack and background score were composed by Bijibal, Red Wine released on 21 March 2013. Assistant Commissioner of Police Ratheesh Vasudevan, tries to solve the murder of Anoop C V, the film was shot on locations in Kozhikode and Wayanad. The film began its shoot and held its pooja on 30 November 2012, the films first teaser was released on 22 December 2012, and a theatrical trailer was released on 5 March 2013. A promotional song was released on 18 March 2013, Red Wine was awarded U certificate by the Central Board of Film Certification. The film received mixed to positive reviews from film critics, aswin of The Times of India says that Red Wine makes it too easy, too effortless and the thin element of suspense wanes no sooner than it even appears. Sify. com rated the film as above Average, stating that Red Wine is not bad, if you are not looking forward to some modern pattern, the film may be a fine option as well. Paresh of Rediff. com says that Red Wine is worth watching for its approach, nirmal of One India says that Red Wine is an interesting film by the super combo of Mohanlal, Fahad Fazal and Asif Ali, a routine murder mystery, but a watchable one. Indiaglitz. com says that Red Wine is a bit of film which can definitely be prescribed for families. One time watch for others though it is predictable to the core. The films soundtrack and background score were composed by Bijibal, with lyrics penned by Rafeeq Ahammed, the album was launched on 7 March 2013 at Crown Plaza in Kochi. The audio rights were acquired by Mathrubhumi Music, official website Red Wine at the Internet Movie Database
Red Wine (film)
–
Theatrical release poster
2.
Wine color
–
The color of wine is one of the most easily recognizable characteristics of wines. Color is also an element in wine tasting since heavy wines generally have a deeper color, the accessory traditionally used to judge the wine color was the tastevin, a shallow cup allowing one to see the color of the liquid in the dim light of a cellar. The color is an element in the classification of wines, the color of the wine mainly depends on the color of the drupe of the grape variety. The Teinturier grape is an exception in that it also has a pigmented pulp, the blending of two or more varieties of grapes can explain the color of certain wines, like the addition of Rubired to intensify redness. Red drupe grapes can produce white wine if they are quickly pressed, the color is mainly due to plant pigments, notably phenolic compounds. The color depends on the presence of acids in the wine, the use of a wooden barrel in aging also affects the color of the wine. The color of a wine can be due to co-pigmentation of anthocyanidins with other non-pigmented flavonoids or natural phenols. Rosé wine is made by the practice of saignée or by blending a white wine with a red wine, the presence of a complex mixture of anthocyanins and procyanidins can increase the stability of color in wine. As it ages, the wine undergoes chemical reactions involving acetaldehyde of its pigments molecules. The newly formed molecules are stable to the effect of pH or sulfite bleaching. The new compounds include pyranoanthocyanins like vitisins, pinotins and portosins, malvidin glucoside-ethyl-catechin is a flavanol-anthocyanin adduct. Flavanol-anthocyanin adducts are formed during wine ageing through reactions between anthocyanins and tannins present in grape, with yeast metabolites such as acetaldehyde, acetaldehyde-induced reactions yield ethyl-linked species such as malvidin glucoside-ethyl-catechin. This compound has a better stability at pH5.5 than malvidin-3O-glucoside. When the pH was increased from 2.2 to 5.5, the exposure of wine to oxygen in limited quantities can be beneficial to the wine. Castavinols are another class of colorless molecules derived from colored anthocyanin pigments, in model solutions, colorless compounds, such as catechin, can give rise to new types of pigments. The first step is the formation of colorless dimeric compounds consisting of two units linked by carboxy-methine bridge. This is followed by the formation of xanthylium salt yellowish pigments and their ethylesters, resulting from the dehydration of the colorless dimers, the loss of a water molecule takes place between two A ring hydroxyl groups of the colorless dimers. The main colors of wine are, Gray, as in vin gris, orange, as in orange wine, a white wine that has spent some time in contact with its skin, giving it a slightly darker hue
Wine color
–
Judging color is the first step in
tasting a wine
Wine color
–
Three glasses of wine colors (from left to right),
white,
red,
rosé and
aged white wine with
brown color.
Wine color
Wine color
3.
Anthocyanins
–
Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue depending on the pH. They belong to a parent class of molecules called flavonoids synthesized via the pathway, they are odorless but flavorful. Anthocyanins occur in all tissues of plants, including leaves, stems, roots, flowers. Anthoxanthins are clear, white to yellow counterparts of anthocyanins occurring in plants, anthocyanins are derived from anthocyanidins by adding sugars. Anthocyanins have an antioxidant role in plants against reactive oxygen species caused by abiotic stresses, such as overexposure to ultraviolet light, tomato plants protect against cold stress with anthocyanins countering reactive oxygen species, leading to a lower rate of cell death in leaves. Anthocyanins are considered secondary metabolites as an additive with E number E163, they are approved for use as a food additive in the EU, Australia. Although anthocyanins have antioxidant properties in vitro, this antioxidant effect is not conserved after the plant is consumed, as interpreted by the Linus Pauling Institute and European Food Safety Authority, dietary anthocyanins and other flavonoids have little or no direct antioxidant food value following digestion. The absorbance pattern responsible for the red color of anthocyanins may be complementary to that of green chlorophyll in photosynthetically active tissues such as young Quercus coccifera leaves and it may protect the leaves from attacks by plant eaters that may be attracted by green color. Anthocyanins are found in the vacuole, mostly in flowers and fruits but also in leaves, stems. In these parts, they are predominantly in outer cell layers such as the epidermis. Most frequently occurring in nature are the glycosides of cyanidin, delphinidin, malvidin, pelargonidin, peonidin, roughly 2% of all hydrocarbons fixed in photosynthesis are converted into flavonoids and their derivatives such as the anthocyanins. Not all land plants contain anthocyanin, in the Caryophyllales, they are replaced by betalains, anthocyanins and betalains have never been found in the same plant. Sometimes bred purposely for high anthocyanin quantities, ornamental plants such as sweet peppers may have unusual culinary, anthocyanins occur in the flowers of many plants, such as the famously blue poppies of some Meconopsis species and cultivars. Red-fleshed peaches and apples contain anthocyanins, anthocyanins are less abundant in banana, asparagus, pea, fennel, pear, and potato, and may be totally absent in certain cultivars of green gooseberries. The highest recorded amount appears to be specifically in the coat of black soybean containing around 2 g per 100 g, in purple corn kernels and husks. Due to critical differences in origin, preparation and extraction methods determining anthocyanin content. The variety known as Indigo Rose became commercially available to the agricultural industry, investing tomatoes with high anthocyanin content doubles their shelf-life and inhibits growth of a post-harvest mold pathogen, Botrytis cinerea. Tomatoes have also been modified with transcription factors from snapdragons to produce high levels of anthocyanins in the fruits
Anthocyanins
–
Anthocyanins give these
pansies their dark purple pigmentation.
Anthocyanins
–
Anthocyanins are
glycosides of
anthocyanidins, the basic chemical structure of which is shown here.
Anthocyanins
–
Red cabbage (anthocyanin dye) extract at low pH (left) to high pH (right)
Anthocyanins
–
A selected purple-leaf cultivar of
European beech
4.
Teinturier
–
In most cases, anthocyanin pigments are confined to the outer skin tissue only, and the squeezed grape juice of most dark-skinned grape varieties is clear. The red color of red wine comes from anthocyanins extracted from the macerated skins, teinturier varieties, while containing a lot of color, usually make special wines, perhaps due to a higher level of tannins, compounds structurally related to the anthocyanins. Many winemakers blend small volumes of teinturier juices into their wines, to boost the colour, Alicante Bouschet Alicante Ganzi Chambourcin Dunkelfelder Gamay de Bouze Grand Noir de la Calmette Morrastel Bouschet Petit Bouschet Royalty Rubired Salvador Saperavi
Teinturier
–
Grapes of the teinturier variety Kolor.
Teinturier
–
An example of the difference between a red fleshed teinturier grape (Agria left) and a red wine grape variety with its skin peeled off to show that its flesh and juice is naturally white (Grenache right). The vast majority of red wine grapes are like the Grenache on the right with the red color of wine coming from skin contact during winemaking.
5.
Winemaker
–
A winemaker or vintner is a person engaged in winemaking. Winemakers can also be referred to as oenologists as they study oenology – the science of wine, a vintner is a wine merchant. In some modern use, particularly in American English, the term is used as a synonym for winemaker. The term started to be used in Middle English, when it superseded the earlier term vinter, a vigneron is someone who cultivates a vineyard for winemaking. The word connotes or emphasizes the role that vineyard placement. It is also used when referring to a winemaker from France, vincent of Saragossa is the patron saint of vignerons. A négociant is the French term for a merchant who assembles the produce of smaller growers and winemakers. Négociants buy everything from grapes to grape must to wines in various states of completion, in the case of grapes or must, the négociant performs virtually all the winemaking. If it buys already fermented wine in barrels or en-vrac—basically in bulk containers, it may age the wine further, blend in other wines or simply bottle, the result is sold under the name of the négociant, not the name of the original grape or wine producer. Currently, one of the largest Negociants in the United States and, some négociants have a recognizable house style. It was too expensive for growers to purchase the wine presses, owning only a small portion of a particular high-quality single vineyard meant that a grower often had insufficient wine from a parcel to vinify on its own. Under French inheritance laws, vineyard holdings were split until offspring owned no more than a single row of grapes. Many négociants are also vineyard owners in their own right, in Burgundy for instance, négociants as Bouchard Père et Fils and Faiveley are among the largest owners of vineyards. Oenology Vignerons indépendants de France Viticulture Winemaking cooperative Winery
Winemaker
–
Merlot grapes grown by Concha y Toro Vineyards for its Casillero del Diablo label are grown in Chile's Rapel Valley
Winemaker
–
Wine grapes.
6.
Winemaking
–
Winemaking or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from fruits or plants. Mead is a wine that is made with honey being the primary ingredient after water, Winemaking can be divided into two general categories, still wine production and sparkling wine production. The science of wine and winemaking is known as oenology, a person who makes wine is traditionally called a winemaker or vintner. After the harvest, the grapes are taken into a winery, at this stage red wine making diverges from white wine making. Red wine is made from the must of red or black grapes and fermentation occurs together with the grape skins, white wine is made by fermenting juice which is made by pressing crushed grapes to extract a juice, the skins are removed and play no further role. Occasionally white wine is made from red grapes, this is done by extracting their juice with minimal contact with the grapes skins. Rosé wines are made from red grapes where the juice is allowed to stay in contact with the dark skins long enough to pick up a pinkish color or by blending red wine with white wine. White and rosé wines extract little of the contained in the skins. To start primary fermentation yeast may be added to the must for red wine or may occur naturally as ambient yeast on the grapes or in the air, yeast may be added to the juice for white wine. During this fermentation, which takes between one and two weeks, the yeast converts most of the sugars in the grape juice into ethanol. The carbon dioxide is lost to the atmosphere, after the primary fermentation of red grapes the free run wine is pumped off into tanks and the skins are pressed to extract the remaining juice and wine. The press wine is blended with the free run wine at the winemakers discretion, the wine is kept warm and the remaining sugars are converted into alcohol and carbon dioxide. The next process in the making of red wine is malo-lactic conversion and this is a bacterial process which converts crisp, green apple malic acid to soft, creamy lactic acid softening the taste of the wine. Red wine is transferred to oak barrels to mature for a period of weeks or months. The wine must be settled or clarified and adjustments made prior to bottling, the time from harvest to drinking can vary from a few months for Beaujolais nouveau wines to over twenty years for wine of good structure with high levels of acid, tannin or sugar. However, only about 10% of all red and 5% of white wine will taste better after five years than it will after just one year. Depending on the quality of grape and the wine style
Winemaking
–
Wine grapes
Winemaking
–
Harvested
Cabernet Sauvignon grapes
Winemaking
–
Central component of a mechanical destemming. Paddles above the small circular slots rotate to remove the larger chunks of stems. Grapes are pulled off the stems and fall through the holes. Some small amount of stem particles are usually desired to be kept with the grapes for tannin structure.
Winemaking
–
Night harvest by hand of wine grapes in
Napa, California
7.
Stainless steel
–
In metallurgy, stainless steel, also known as inox steel or inox from French inoxydable, is a steel alloy with a minimum of 10. 5% chromium content by mass. Stainless steel is notable for its resistance, and it is widely used for food handling. Stainless steel does not readily corrode, rust or stain with water as ordinary steel does, however, it is not fully stain-proof in low-oxygen, high-salinity, or poor air-circulation environments. There are various grades and surface finishes of stainless steel to suit the environment the alloy must endure, Stainless steel is used where both the properties of steel and corrosion resistance are required. Stainless steel differs from carbon steel by the amount of chromium present, unprotected carbon steel rusts readily when exposed to air and moisture. This iron oxide film is active and accelerates corrosion by making it easier for more iron oxide to form, since iron oxide has lower density than steel, the film expands and tends to flake and fall away. In comparison, stainless steels contain sufficient chromium to undergo passivation and this layer prevents further corrosion by blocking oxygen diffusion to the steel surface and stops corrosion from spreading into the bulk of the metal. Passivation occurs only if the proportion of chromium is high enough, Stainless steel’s resistance to corrosion and staining, low maintenance, and familiar lustre make it an ideal material for many applications. Storage tanks and tankers used to transport orange juice and other food are made of stainless steel. This also influences its use in kitchens and food processing plants, as it can be steam-cleaned and sterilized. High oxidation resistance in air at ambient temperature is achieved with addition of a minimum of 13% chromium. The chromium forms a layer of chromium oxide when exposed to oxygen. The layer is too thin to be visible, and the metal remains lustrous, the layer is impervious to water and air, protecting the metal beneath, and this layer quickly reforms when the surface is scratched. This phenomenon is called passivation and is seen in other metals, corrosion resistance can be adversely affected if the component is used in a non-oxygenated environment, a typical example being underwater keel bolts buried in timber. When stainless steel parts such as nuts and bolts are forced together, when forcibly disassembled, the welded material may be torn and pitted, a destructive effect known as galling. Galling can be avoided by the use of materials for the parts forced together, for example bronze and stainless steel. However, two different alloys electrically connected in a humid, even mildly acidic environment may act as a voltaic pile, nitronic alloys, made by selective alloying with manganese and nitrogen, may have a reduced tendency to gall. Additionally, threaded joints may be lubricated to provide a film between the two parts and prevent galling, low-temperature carburizing is another option that virtually eliminates galling and allows the use of similar materials without the risk of corrosion and the need for lubrication
Stainless steel
–
Steels and other iron–carbon alloy phases
Stainless steel
–
An announcement, as it appeared in the 1915 New York Times, of the development of stainless steel
Stainless steel
–
The 630-foot-high (190 m), stainless-clad (type 304)
Gateway Arch defines
St. Louis's skyline
Stainless steel
–
The pinnacle of New York's Chrysler Building is clad with Nirosta stainless steel, a form of Type 302
8.
Oxidation
–
Redox is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a process and a complementary oxidation process, two key concepts involved with electron transfer processes. Redox reactions include all chemical reactions in which atoms have their oxidation state changed, in general, the chemical species from which the electron is stripped is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. It can be explained in terms, Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom. Reduction is the gain of electrons or a decrease in state by a molecule, atom. As an example, during the combustion of wood, oxygen from the air is reduced, the reaction can occur relatively slowly, as in the case of rust, or more quickly, as in the case of fire. Redox is a portmanteau of reduction and oxidation, the word oxidation originally implied reaction with oxygen to form an oxide, since dioxygen was historically the first recognized oxidizing agent. Later, the term was expanded to encompass oxygen-like substances that accomplished parallel chemical reactions, ultimately, the meaning was generalized to include all processes involving loss of electrons. The word reduction originally referred to the loss in weight upon heating a metallic ore such as an oxide to extract the metal. In other words, ore was reduced to metal, antoine Lavoisier showed that this loss of weight was due to the loss of oxygen as a gas. Later, scientists realized that the atom gains electrons in this process. The meaning of reduction then became generalized to all processes involving gain of electrons. Even though reduction seems counter-intuitive when speaking of the gain of electrons, it help to think of reduction as the loss of oxygen. Since electrons are charged, it is also helpful to think of this as reduction in electrical charge. The electrochemist John Bockris has used the words electronation and deelectronation to describe reduction and oxidation processes respectively when they occur at electrodes and these words are analogous to protonation and deprotonation, but they have not been widely adopted by chemists. The term hydrogenation could be used instead of reduction, since hydrogen is the agent in a large number of reactions. But, unlike oxidation, which has been generalized beyond its root element, the word redox was first used in 1928. The processes of oxidation and reduction occur simultaneously and cannot happen independently of one another, the oxidation alone and the reduction alone are each called a half-reaction, because two half-reactions always occur together to form a whole reaction
Oxidation
–
Rusting iron
Oxidation
–
Sodium and
fluorine bonding ionically to form
sodium fluoride. Sodium loses its outer
electron to give it a stable
electron configuration, and this electron enters the fluorine atom
exothermically. The oppositely charged ions are then attracted to each other. The sodium is oxidized, and the fluorine is reduced.
Oxidation
–
A
bonfire
Oxidation
–
Oxides, such as
iron(III) oxide or
rust, which consists of hydrated
iron(III) oxides Fe 2 O 3 · n H 2 O and
iron(III) oxide-hydroxide (FeO(OH), Fe(OH) 3), form when oxygen combines with other elements
9.
Fermentation (wine)
–
The process of fermentation in winemaking turns grape juice into an alcoholic beverage. During fermentation, yeasts transform sugars present in the juice into ethanol, in winemaking, the temperature and speed of fermentation are important considerations as well as the levels of oxygen present in the must at the start of the fermentation. The natural occurrence of fermentation means it was probably first observed long ago by humans, the Latin fervere means, literally, to boil. The most common genera of yeasts found in winemaking include Candida, Klöckera/Hanseniaspora, Metschnikowiaceae, Pichia. Wild yeasts can produce high-quality, unique-flavored wines, however, they are unpredictable and may introduce less desirable traits to the wine. The cultured yeasts most commonly used in winemaking belong to the Saccharomyces cerevisiae species, the use of different strains of yeasts is a major contributor to the diversity of wine, even among the same grape variety. Alternative, non-Saccharomyces cerevisiae, yeasts are being used more prevalently in the industry to add complexity to wine. After a winery has been in operation for a number of years, the use of active dry yeasts reduces the variety of strains that appear in spontaneous fermentation by outcompeting those strains that are naturally present. The addition of cultured yeast normally occurs with the yeast first in a dried or inactive state and is reactivated in warm water or diluted grape juice prior to being added to the must. To thrive and be active in fermentation, the yeast needs access to a supply of carbon, nitrogen, sulfur, phosphorus as well as access to various vitamins. These components are present in the grape must but their amount may be corrected by adding nutrients to the wine. Newly formulated time-release nutrients, specifically manufactured for wine fermentations, offer the most advantageous conditions for yeast. Oxygen is needed as well, but in making, the risk of oxidation. During this process, the carbon atom is released in the form of carbon dioxide with the remaining components becoming acetaldehyde. The absence of oxygen in this process allows the acetaldehyde to be eventually converted, by reduction. During the conversion of acetaldehyde, an amount is converted, by oxidation, to acetic acid which, in excess. After the yeast has exhausted its life cycle, they fall to the bottom of the tank as sediment known as lees. The metabolism of amino acids and breakdown of sugars by yeasts has the effect of creating other biochemical compounds that can contribute to the flavor and aroma of wine
Fermentation (wine)
–
Fermenting
must
Fermentation (wine)
–
"Bloom", visible as a dusting on the berries
Fermentation (wine)
–
Dry winemaking yeast (left) and yeast nutrients used in the rehydration process to stimulate yeast cells.
Fermentation (wine)
–
Carbon dioxide is visible during the fermentation process in the form of bubbles in the must.
10.
Enzyme
–
Enzymes /ˈɛnzaɪmz/ are macromolecular biological catalysts. Enzymes accelerate, or catalyze, chemical reactions, the molecules at the beginning of the process upon which enzymes may act are called substrates and the enzyme converts these into different molecules, called products. Almost all metabolic processes in the cell need enzymes in order to occur at rates fast enough to sustain life, the set of enzymes made in a cell determines which metabolic pathways occur in that cell. The study of enzymes is called enzymology, enzymes are known to catalyze more than 5,000 biochemical reaction types. Most enzymes are proteins, although a few are catalytic RNA molecules, enzymes specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the rate of a reaction by lowering its activation energy, some enzymes can make their conversion of substrate to product occur many millions of times faster. An extreme example is orotidine 5-phosphate decarboxylase, which allows a reaction that would take millions of years to occur in milliseconds. Chemically, enzymes are like any catalyst and are not consumed in chemical reactions, enzymes differ from most other catalysts by being much more specific. Enzyme activity can be affected by other molecules, inhibitors are molecules that decrease enzyme activity, many drugs and poisons are enzyme inhibitors. An enzymes activity decreases markedly outside its optimal temperature and pH, some enzymes are used commercially, for example, in the synthesis of antibiotics. French chemist Anselme Payen was the first to discover an enzyme, diastase and he wrote that alcoholic fermentation is an act correlated with the life and organization of the yeast cells, not with the death or putrefaction of the cells. In 1877, German physiologist Wilhelm Kühne first used the term enzyme, the word enzyme was used later to refer to nonliving substances such as pepsin, and the word ferment was used to refer to chemical activity produced by living organisms. Eduard Buchner submitted his first paper on the study of yeast extracts in 1897, in a series of experiments at the University of Berlin, he found that sugar was fermented by yeast extracts even when there were no living yeast cells in the mixture. He named the enzyme that brought about the fermentation of sucrose zymase, in 1907, he received the Nobel Prize in Chemistry for his discovery of cell-free fermentation. Following Buchners example, enzymes are usually named according to the reaction they carry out, the biochemical identity of enzymes was still unknown in the early 1900s. Sumner showed that the enzyme urease was a protein and crystallized it. These three scientists were awarded the 1946 Nobel Prize in Chemistry, the discovery that enzymes could be crystallized eventually allowed their structures to be solved by x-ray crystallography. This high-resolution structure of lysozyme marked the beginning of the field of structural biology, an enzymes name is often derived from its substrate or the chemical reaction it catalyzes, with the word ending in -ase
Enzyme
–
Eduard Buchner
Enzyme
–
The enzyme
glucosidase converts sugar
maltose to two
glucose sugars. Active site residues in red, maltose substrate in black, and NAD cofactor in yellow. (
PDB: 1OBB )
11.
Tannin (wine)
–
These compounds include phenolic acids, stilbenoids, flavonols, dihydroflavonols, anthocyanins, flavanol monomers and flavanol polymers. This large group of natural phenols can be separated into two categories, flavonoids and non-flavonoids. Flavonoids include the anthocyanins and tannins which contribute to the color, the non-flavonoids include the stilbenoids such as resveratrol and phenolic acids such as benzoic, caffeic and cinnamic acids. The natural phenols are not evenly distributed within the fruit, phenolic acids are largely present in the pulp, anthocyanins and stilbenoids in the skin, and other phenols in the skin and the seeds. During the growth cycle of the grapevine, sunlight will increase the concentration of phenolics in the grape berries, the proportion of the different phenols in any one wine will therefore vary according to the type of vinification. Red wines will also have the phenols found in white wines, anthocyanins react with catechins, proanthocyanidins and other wine components during wine aging to form new polymeric pigments resulting in a modification of the wine color and a lower astringency. Average total polyphenol content measured by the Folin method is 216 mg/100 ml for red wine and 32 mg/100 ml for white wine, the content of phenols in rosé wine is intermediate between that in red and white wines. In winemaking, the process of maceration or skin contact is used to increase the concentration of phenols in wine, phenolic acids are found in the pulp or juice of the wine and can be commonly found in white wines which usually do not go through a maceration period. The process of oak aging can also introduce phenolic compounds into wine, most wine phenols are classified as secondary metabolites and were not thought to be active in the primary metabolism and function of the grapevine. However, there is evidence that in some plants flavonoids play a role as regulators of auxin transport. They are water-soluble and are secreted into the vacuole of the grapevine as glycosides. Vitis vinifera produces many phenolic compounds, there is a varietal effect on the relative composition. In red wine, up to 90% of the phenolic content falls under the classification of flavonoids. These phenols, mainly derived from the stems, seeds and skins are often leached out of the grape during the period of winemaking. The amount of phenols leached is known as extraction and these compounds contribute to the astringency, color and mouthfeel of the wine. In white wines the number of flavonoids is reduced due to the contact with the skins that they receive during winemaking. There is on-going study into the benefits of wine derived from the antioxidant. Within the flavonoid category is a known as flavonols, which includes the yellow pigment - quercetin
Tannin (wine)
–
The phenolic compounds in Syrah grapes contribute to the taste, color and mouthfeel of the wine.
Tannin (wine)
–
The process of
maceration or extended skin contact allows the extraction of phenolic compounds (including those that form a wine's color) from the skins of the grape into the wine.
Tannin (wine)
–
Tempranillo has a high pH level which means that there is a higher concentration of blue and colorless anthocyanin pigments in the wine. The resulting wine's coloring will have more blue hues than bright ruby red hues.
Tannin (wine)
–
Fermenting with the stem, seeds and skin will increase the tannin content of the wine.
12.
Alcohol
–
In chemistry, an alcohol is any organic compound in which the hydroxyl functional group is bound to a saturated carbon atom. The term alcohol originally referred to the alcohol ethanol, the predominant alcohol in alcoholic beverages. The suffix -ol in non-systematic names also typically indicates that the substance includes a functional group and, so. But many substances, particularly sugars contain hydroxyl functional groups without using the suffix, an important class of alcohols, of which methanol and ethanol are the simplest members is the saturated straight chain alcohols, the general formula for which is CnH2n+1OH. The word alcohol is from the Arabic kohl, a used as an eyeliner. Al- is the Arabic definite article, equivalent to the in English, alcohol was originally used for the very fine powder produced by the sublimation of the natural mineral stibnite to form antimony trisulfide Sb 2S3, hence the essence or spirit of this substance. It was used as an antiseptic, eyeliner, and cosmetic, the meaning of alcohol was extended to distilled substances in general, and then narrowed to ethanol, when spirits as a synonym for hard liquor. Bartholomew Traheron, in his 1543 translation of John of Vigo, Vigo wrote, the barbarous auctours use alcohol, or alcofoll, for moost fine poudre. The 1657 Lexicon Chymicum, by William Johnson glosses the word as antimonium sive stibium, by extension, the word came to refer to any fluid obtained by distillation, including alcohol of wine, the distilled essence of wine. Libavius in Alchymia refers to vini alcohol vel vinum alcalisatum, Johnson glosses alcohol vini as quando omnis superfluitas vini a vino separatur, ita ut accensum ardeat donec totum consumatur, nihilque fæcum aut phlegmatis in fundo remaneat. The words meaning became restricted to spirit of wine in the 18th century and was extended to the class of substances so-called as alcohols in modern chemistry after 1850, the term ethanol was invented 1892, based on combining the word ethane with ol the last part of alcohol. In the IUPAC system, in naming simple alcohols, the name of the alkane chain loses the terminal e and adds ol, e. g. as in methanol and ethanol. When necessary, the position of the group is indicated by a number between the alkane name and the ol, propan-1-ol for CH 3CH 2CH 2OH, propan-2-ol for CH 3CHCH3. If a higher priority group is present, then the prefix hydroxy is used, in other less formal contexts, an alcohol is often called with the name of the corresponding alkyl group followed by the word alcohol, e. g. methyl alcohol, ethyl alcohol. Propyl alcohol may be n-propyl alcohol or isopropyl alcohol, depending on whether the group is bonded to the end or middle carbon on the straight propane chain. As described under systematic naming, if another group on the molecule takes priority, Alcohols are then classified into primary, secondary, and tertiary, based upon the number of carbon atoms connected to the carbon atom that bears the hydroxyl functional group. The primary alcohols have general formulas RCH2OH, the simplest primary alcohol is methanol, for which R=H, and the next is ethanol, for which R=CH3, the methyl group. Secondary alcohols are those of the form RRCHOH, the simplest of which is 2-propanol, for the tertiary alcohols the general form is RRRCOH
Alcohol
–
Biofuels
Alcohol
–
Ball-and-stick model of the hydroxyl (-OH) functional group in an alcohol molecule (R 3 COH). The three "R's" stand for carbon substituents or hydrogen atoms.
13.
Yeast (wine)
–
The role of yeast in winemaking is the most important element that distinguishes wine from grape juice. In the absence of oxygen, yeast converts the sugars of wine grapes into alcohol, the more sugars in the grapes, the higher the potential alcohol level of the wine if the yeast are allowed to carry out fermentation to dryness. Sometimes winemakers will stop fermentation early in order to some residual sugars. If fermentation is stopped, such as when the yeasts become exhausted of available nutrients. Despite its widespread use which often includes deliberate inoculation from cultured stock, grapes brought in from harvest are usually teeming with a variety of wild yeast from the Kloeckera and Candida genera. These yeasts often begin the process almost as soon as the grapes are picked when the weight of the clusters in the harvest bins begin to crush the grapes. For most of the history of wine, winemakers did not know the mechanism that somehow converted sugary grape juice into alcoholic wine and this history is preserved in the etymology of the word yeast itself which essentially means to boil. In the mid-19th century, the French scientist Louis Pasteur was tasked by the French government to study what made some wines spoil. His work, which would lead to Pasteur being considered one of the Fathers of Microbiology. The yeast species commonly known as Saccharomyces cerevisiae was first identified in late 19th century enology text as Saccharomyces ellipsoideus due to the shape of the cells. Throughout the 20th century, more than 700 different strains of Saccharomyces cerevisiae were identified, some of these difference include the vigor or speed of fermentation, temperature tolerance, the production of volatile sulfur compounds and other compounds that may influence the aroma of the wine. The primary role of yeast is to convert the present in the grape must into alcohol. It is through this process of fermentation that ethanol is released by the yeast cells as a waste product and this includes glycerol which is produced when an intermediate of the glycolysis cycle is reduced to recharge the NADH enzyme needed to continue other metabolic activities. This is usually produced early in the process before the mechanisms to reduce acetaldehyde into ethanol to recharge NADH becomes the cells primary means of maintaining redox balance. This includes selecting yeast strains that favor glycerol production, increased oxygen exposure, other by-products of yeast include, Methanol – Caused by the demethylation of pectins in the must by enzymes of the yeast. More commonly found in red wines than white but only in small amounts between 20–200 mg/L. Fusel oils – Formed by the decomposition of amino acids by the yeast, succinic acid – Like glycerol, this is often formed early in fermentation. Usually found in concentrations of 500–1200 mg/L, it is an acid in the overall acidity of wine
Yeast (wine)
–
The process of fermentation at work on Pinot noir. As yeast consume the sugar in the must it releases alcohol and carbon dioxide (seen here as the foaming bubbles) as byproducts.
Yeast (wine)
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French scientist Louis Pasteur discovered the connection between microscopic yeast and the process of fermentation.
Yeast (wine)
–
In the absence of oxygen, yeast cells will take the pyruvate produced by glycolysis and reduce it into acetaldehyde which is further reduced into ethanol "recharging" the NAD+ co-enzymes that is needed for various metabolic processes of the yeast.
Yeast (wine)
–
If a Chardonnay has too much "buttery" diacetyl notes, winemakers may add fresh yeast to the wine to consume the diacetyl and reduce it to the more neutral-smelling fusel oil 2,3-Butanediol.
14.
Saccharomyces cerevisiae
–
Saccharomyces cerevisiae is a species of yeast. It has been instrumental to winemaking, baking, and brewing since ancient times and it is believed to have been originally isolated from the skin of grapes. It is one of the most intensively studied model organisms in molecular and cell biology. It is the microorganism behind the most common type of fermentation, S. cerevisiae cells are round to ovoid, 5–10 μm in diameter. It reproduces by a process known as budding. Many proteins important in biology were first discovered by studying their homologs in yeast, these proteins include cell cycle proteins, signaling proteins. S. cerevisiae is currently the only yeast cell known to have Berkeley bodies present, antibodies against S. cerevisiae are found in 60–70% of patients with Crohns disease and 10–15% of patients with ulcerative colitis. Saccharomyces derives from Latinized Greek and means sugar-mold or sugar-fungus, saccharo being the combining form sugar, cerevisiae comes from Latin and means of beer. Refinements in microbiology following the work of Louis Pasteur led to more advanced methods of culturing pure strains, in 1879, Great Britain introduced specialized growing vats for the production of S. The company created yeast that would rise twice as fast, cutting down on baking time, lesaffre would later create instant yeast in the 1970s, which has gained considerable use and market share at the expense of both fresh and dry yeast in their various applications. In nature, yeast cells are primarily on ripe fruits such as grapes. Since S. cerevisiae is not airborne, it requires a vector to move, queens of social wasps overwintering as adults can harbor yeast cells from autumn to spring and transmit them to their progeny. The intestine of Polistes dominula, a wasp, hosts S. cerevisiae strains as well as S. cerevisiae × S. paradoxus hybrids. The optimum temperature for growth of S. cerevisiae is 30–35 °C, two forms of yeast cells can survive and grow, haploid and diploid. The haploid cells undergo a simple lifecycle of mitosis and growth and this is the asexual form of the fungus. The diploid cells undergo a simple lifecycle of mitosis and growth. The rate at which the cell cycle progresses often differs substantially between haploid and diploid cells. Under conditions of stress, diploid cells can undergo sporulation, entering meiosis and producing four haploid spores and this is the sexual form of the fungus
Saccharomyces cerevisiae
–
Saccharomyces cerevisiae
Saccharomyces cerevisiae
–
Yeast colonies on an agar plate.
Saccharomyces cerevisiae
–
Saccharomyces cerevisiae Numbered ticks are 10 micrometers apart.
Saccharomyces cerevisiae
–
Types
15.
Density
–
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. The symbol most often used for density is ρ, although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume, ρ = m V, where ρ is the density, m is the mass, and V is the volume. In some cases, density is defined as its weight per unit volume. For a pure substance the density has the numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity, osmium and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser. Thus a relative density less than one means that the floats in water. The density of a material varies with temperature and pressure and this variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object, increasing the temperature of a substance decreases its density by increasing its volume. In most materials, heating the bottom of a results in convection of the heat from the bottom to the top. This causes it to rise relative to more dense unheated material, the reciprocal of the density of a substance is occasionally called its specific volume, a term sometimes used in thermodynamics. Density is a property in that increasing the amount of a substance does not increase its density. Archimedes knew that the irregularly shaped wreath could be crushed into a cube whose volume could be calculated easily and compared with the mass, upon this discovery, he leapt from his bath and ran naked through the streets shouting, Eureka. As a result, the term eureka entered common parlance and is used today to indicate a moment of enlightenment, the story first appeared in written form in Vitruvius books of architecture, two centuries after it supposedly took place. Some scholars have doubted the accuracy of this tale, saying among other things that the method would have required precise measurements that would have been difficult to make at the time, from the equation for density, mass density has units of mass divided by volume. As there are units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The SI unit of kilogram per metre and the cgs unit of gram per cubic centimetre are probably the most commonly used units for density.1,000 kg/m3 equals 1 g/cm3. In industry, other larger or smaller units of mass and or volume are often more practical, see below for a list of some of the most common units of density
Density
–
Air density vs. temperature
16.
Pressing (wine)
–
Pressing in winemaking is the process where juice is extracted from grapes. This can be done with the aid of a press, by hand, or even by the weight of the own grape berries. In white wine production, pressing usually takes place immediately after crushing or/and before primary fermentation, approximately 60-70% of the available juice within the grape berry, the free-run juice, can be released by the crushing process and doesnt require the use of the press. In practice the volume of many wines are made from 85-90% of free-run juice, the timing of pressing and the methods used will influence other decisions in the winemaking process. In white wine making, pressing usually happens immediately after harvest, here, the biggest decision will be how much pressure to apply and how much pressed juice the winemakers wants in addition to the free-run juice. Some grape varieties, such as Sémillon and Aurore have very liquidy pulps that releases juice easily without needing much pressure that could risk tearing the skins, other varieties, such as Catawba, have much tougher pulps that will require more pressing. In red wine production the timing of when to press is one of the most important decisions in the making process since that will be the moment that maceration. Some winemakers use the sugar level scale and press once the wine has reached complete dryness. Often winemakers will use taste to determine if the wine has extracted enough tannins to produce a balanced wine, in these years winemakers might press early, a process that the Australians call short vatting. Grape pulp contains a lot of pectins that create colloid coagulation with these solids that will make the difficult to stabilize. Some winemakers will use pectolytic enzymes during the process to help break down the cell walls to allow the release of more juice freely. These enzymes are used with white wines to assist in clarification. The type of pressing used and the amount of suspended solids plays a role in filtering decisions as a high amount of suspended solids can clog. The earliest wine press was likely the human foot or hand, the pressure applied by these manual means was limited and these early wines were likely pale in color and body. Eventually humans discovered that more juice could be extracted and potentially a better wine could be produced if they developed ways of pressing and it begin with the ancient Egyptians who developed a sack press made of cloth that was squeezed with the aid of a giant tourniquet. The ancient Greeks and Romans developed large wooden wine presses that utilized large beams, capstans and that style of wine press would eventually evolve into the basket press used in the Middle Ages by wine estates of the nobility and Catholic Church. There are many records that showed feudal land tenants were willing to pay a portion of their crop to use a landlords wine press if it was available. This was likely because added volume of wine that pressing could produce versus manual treading was substantial enough to justify the cost, winemaking text began recommending the use of mechanical pressings over feet treading in lagars
Pressing (wine)
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Viognier juice in the press pan after being pressed.
Pressing (wine)
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The decision on when to press red wine grapes will have an influence on color since color phenolics and tannins are extracted from the grapes during maceration prior to pressing.
Pressing (wine)
–
First developed in the Middle Ages, basket presses have a long history of use in winemaking.
Pressing (wine)
–
A basket press with half of its slats removed to show the compact pomace "cake" that develops from the leftover skins, seeds and stems after pressing. This cake needs to be cleaned out and removed after each batch.
17.
Wine press
–
A wine press is a device used to extract juice from crushed grapes during wine making. There are a number of different styles of presses that are used by wine makers, each style of press exerts controlled pressure in order to free the juice from the fruit. The pressure must be controlled, especially grapes, in order to avoid crushing the seeds. Wine was being made at least as long ago as 6000 BC, in 2011, a basket press consists of a large basket filled with the crushed grapes. Pressure is applied through a plate that is forced down onto the fruit, the mechanism to lower the plate is often either a screw or a hydraulic device. The juice flows through openings in the basket, the basket style press was the first type of mechanized press to be developed, and its basic design has not changed in nearly 1000 years. A horizontal screw press works using the principle as the basket press. Instead of a plate being brought down to put pressure on the grapes, plates from either side of a cylinder are brought together to squeeze the grapes. Generally the volume of grapes handled is significantly greater than that of a basket press, a bladder press consists of a large cylinder, closed at each end, into which the fruit is loaded. To press the grapes, a large bladder expands and pushes the grapes against the sides, the juice then flows out through small openings in the cylinder. The cylinder rotates during the process to help homogenize the pressure that is placed on the grapes, a continuous screw press differs from the above presses in that it does not process a single batch of grapes at a time. Instead it uses an Archimedes screw to continuously force grapes up against the wall of the device, juice is extracted, and the pomace continues through to the end where it is extracted. This style of press is used to produce table wines. Flash release is a used in wine pressing. The technique allows for an extraction of phenolic compounds
Wine press
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16th century wine press
Wine press
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Modern wine press
Wine press
–
Ancient wine press in
Israel with the pressing area in the center and the collection vat off to the bottom left.
Wine press
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A bladder press
18.
History of the wine press
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The earliest wine press was probably the human foot or hand, crushing and squeezing grapes into a bag or container where the contents would ferment. By at least the 18th dynasty, the ancient Egyptians were employing a sack made of cloth that was squeezed with the aid of a giant tourniquet. The wines produced by these presses were usually darker, with more color extracted from the skins, in the 17th century, French traveller Sir Jean Chardin would describe a similar practice still in use thousands of years later in Georgia. The earliest evidence of deliberate winemaking is from excavation at sites like Areni-1 winery in what is now the Vayots Dzor Province of Armenia. This site, dating back to around 4000 BC included a trough that measured about 3 by 3 1/2 feet, a modified version of this sack press had the sack hung between two large poles with workers holding each pole. After the grapes were loaded into the sack, the workers would walk in opposite directions, squeezing the grapes in the bag and capturing the juice in a vat underneath the bag. This early wine press not only had the benefit of exerting pressure on the skins and extracting more juice than treading. One of the earliest known Greek wine presses was discovered in Palekastro in Crete, like most of the earlier presses, it was mainly a stone basin for treading the grapes by feet with a run off drain for the juice to flow. However, there is evidence that some of the later Cretan winemakers would use a pressing method similar to how olive oil was extracted from olives. This press would entail laying the grapes out underneath several planks of wood, the wine made from these rudimentary pressing wasnt held in high esteem by the Greeks, often tainted with impurities and having a short shelf life. Much more prized was the produced from free run juice that was released by the grapes under their own weight before any treading or pressing. This wine was believed to be the most pure and was used for medicinal purposes. In the 2nd century BC, Cato the Elder wrote a vivid and detailed account of the workings of early Roman wine presses, the press would consist of a large horizontal beam held up by two upright fixtures in the front and on upright fixture in the front. The grapes were placed under the beam with pressure was applied by a windlass that was affixed by rope to the front of the beam, rope would also be used wound around the cake of the pressed grape skins to help keep it in place. Marcus Terentius Varro, Columella and Virgil would also include descriptions of the workings of wine presses in their agricultural treatises, yet despite their frequent mentions in ancient writings and archaeological evidence showing the presence of wine presses throughout the Roman empire, their use was actually relatively rare. This was because having a press was a very expensive and large piece of equipment that most Roman farmers, outside the estate holding patricians. Instead, it was more common for Roman estates to have large tanks or trough where grapes were tread upon by feet or paddles. Varro also described in his work De re rustica a type of pressed wine known as lorca that was produced by the left over grape skins being soaked in water that was served to slaves and farm workers
History of the wine press
–
The very first wine press was probably the human foot and the use of manual treading of grapes is a tradition that has lasted for thousands of years and is still used in some wine regions today.
History of the wine press
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Ancient Egyptian pressing basin, where grapes were probably trodden by human feet in the Marea region around present day
Lake Mariout.
History of the wine press
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A 1st century AD wine pressing trough from the
Old City of Jerusalem.
History of the wine press
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One of the first written account of a mechanical wine press was from the 2nd century BC Roman writer Marcus Cato.
19.
Crusher/destemmer
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Winemaking or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from fruits or plants. Mead is a wine that is made with honey being the primary ingredient after water, Winemaking can be divided into two general categories, still wine production and sparkling wine production. The science of wine and winemaking is known as oenology, a person who makes wine is traditionally called a winemaker or vintner. After the harvest, the grapes are taken into a winery, at this stage red wine making diverges from white wine making. Red wine is made from the must of red or black grapes and fermentation occurs together with the grape skins, white wine is made by fermenting juice which is made by pressing crushed grapes to extract a juice, the skins are removed and play no further role. Occasionally white wine is made from red grapes, this is done by extracting their juice with minimal contact with the grapes skins. Rosé wines are made from red grapes where the juice is allowed to stay in contact with the dark skins long enough to pick up a pinkish color or by blending red wine with white wine. White and rosé wines extract little of the contained in the skins. To start primary fermentation yeast may be added to the must for red wine or may occur naturally as ambient yeast on the grapes or in the air, yeast may be added to the juice for white wine. During this fermentation, which takes between one and two weeks, the yeast converts most of the sugars in the grape juice into ethanol. The carbon dioxide is lost to the atmosphere, after the primary fermentation of red grapes the free run wine is pumped off into tanks and the skins are pressed to extract the remaining juice and wine. The press wine is blended with the free run wine at the winemakers discretion, the wine is kept warm and the remaining sugars are converted into alcohol and carbon dioxide. The next process in the making of red wine is malo-lactic conversion and this is a bacterial process which converts crisp, green apple malic acid to soft, creamy lactic acid softening the taste of the wine. Red wine is transferred to oak barrels to mature for a period of weeks or months. The wine must be settled or clarified and adjustments made prior to bottling, the time from harvest to drinking can vary from a few months for Beaujolais nouveau wines to over twenty years for wine of good structure with high levels of acid, tannin or sugar. However, only about 10% of all red and 5% of white wine will taste better after five years than it will after just one year. Depending on the quality of grape and the wine style
Crusher/destemmer
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Wine grapes
Crusher/destemmer
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Harvested
Cabernet Sauvignon grapes
Crusher/destemmer
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Central component of a mechanical destemming. Paddles above the small circular slots rotate to remove the larger chunks of stems. Grapes are pulled off the stems and fall through the holes. Some small amount of stem particles are usually desired to be kept with the grapes for tannin structure.
Crusher/destemmer
–
Night harvest by hand of wine grapes in
Napa, California
20.
Sparkling wine production
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Sparkling wine is a wine that becomes carbonated, either through fermentation or by addition of carbon dioxide. The oldest known production of sparkling wine took place in 1531 with the ancestral method, Champagne is the most well-known variant, but there are other variations such as Spanish Cava, Italian Spumante, Crémant from France and Sekt from Germany. Overall, more or less dry wines are most common among the sparkling wines. In popular parlance and also in the title of this article the term sparkling is used for all wines that produce bubbles at the surface after opening, under EU law the term sparkling has a special meaning that does not include all wines that produce bubbles. For this reason the terms fizzy and effervescent are sometimes used to include all bubbly wines, the following terms are increasingly used to designate different bottle pressures, Beady is a wine with less than 1 additional bar of pressure. Semi-sparkling is a wine with 1 to 2.5 additional bars of pressure, semi-sparkling wines include wines labelled as Frizzante, Spritzig, Pétillant and Pearl. Sparkling is a wine with above 3 additional bars of pressure and this is the only wine that can be labelled as sparkling under EU law. Sparkling wines include wines labelled as Champagne, Cava, Mousseux, Crémant, Espumoso, Sekt, fermentation of sugar into alcohol during winemaking always means that carbon dioxide is released. Carbon dioxide has the property of being soluble in water. Production always starts from a base wine, Champagne production the base wine is usually a blend of wines from different grape varieties and different wineries, where the distribution gives the final wine its special character, called cuvée. In some commonly used methods the base wine undergoes a secondary fermentation, in this way the carbon dioxide content is created which, after opening the bottle, produces the bubbles. The dead yeast cells form a precipitate called lees, that helps with appealing aromas to the sparkling wine. The lees is therefore normally removed before the wine is distributed, the main methods used to make sparkling wines are often given as seven, with some variations. The following table shows the features of each method. The methods are described in the text. It should be noted that each method there may be variations from one producer to another. The so-called classic way to sparkling wine is popularly known as the Champagne method or méthode classique which is the official EU designation. Formerly, the designation was méthode champenoise but this designation is no longer permitted, as the former designation suggests, the method is used for the production of most Champagne, and it is slightly more expensive than the Charmat method
Sparkling wine production
–
All production methods for sparkling wines have one thing in common: they have the purpose of introducing enough carbon dioxide in the wine to make it effervescent.
Sparkling wine production
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Champagne bottles in racks in underground cellars
Sparkling wine production
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The larger Champagne producers have a number of press houses situated throughout the region, such as this
Moët & Chandon facility.
Sparkling wine production
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A bottle of undisgorged Champagne resting on the lees. The yeast used in the second
fermentation is still in the bottle, which is closed with a
crown cap.
21.
Champagne (wine region)
–
The Champagne wine region is a wine region within the historical province of Champagne in the northeast of France. The area is best known for the production of the white wine that bears the regions name. EU law and the laws of most countries reserve the term Champagne exclusively for wines that come from this region located about 100 miles east of Paris, the towns of Reims and Épernay are the commercial centers of the area. Located at the edges of France, the history of the Champagne wine region has had a significant role in the development of this unique terroir. The areas proximity to Paris promoted the economic success in its wine trade but also put the villages. The principal grapes grown in the region include Chardonnay, Pinot noir, Pinot noir is the most widely planted grape in the Aube region and grows very well in Montagne de Reims. Pinot Meunier is the dominant grape in the Vallée de la Marne region, the Côte des Blancs is dedicated almost exclusively to Chardonnay. The Champagne province is located near the limits of the wine world along the 49th parallel. The high altitude and mean temperature of 10 °C creates a difficult environment for wine grapes to fully ripen. Ripening is aided by the presence of forests which helps to stabilize temperatures, the cool temperatures serve to produce high levels of acidity in the resulting grape which is ideal for sparkling wine. During the growing season, the mean July temperature is 18 °C, the average annual rainfall is 630 mm, with 45 mm falling during the harvest month of September. Throughout the year, growers must be mindful of the hazards of fungal disease, ancient oceans left behind chalk subsoil deposits when they receded 70 million years ago. Earthquakes that rocked the region over 10 million years ago pushed the marine sediments of belemnite fossils up to the surface to create the belemnite chalk terrain. The belemnite in the soil allows it to heat from the sun. This soil contributes to the lightness and finesse that is characteristic of Champagne wine, the Aube area is an exception with predominately clay based soil. The chalk is used in the construction of underground cellars that can keep the wines cool through the bottle maturation process. The tradition of crowning kings at Reims contributed to the reputation of the wines that came from this area, the Counts of Champagne ruled the area as an independent county from 950 to 1316. In 1314, the last Count of Champagne assumed the throne as King Louis X of France, the location of Champagne played a large role in its historical prominence as it served as a crossroads for both military and trade routes
Champagne (wine region)
–
Champagne vineyards in
Verzenay in the Montagne de Reims subregion
Champagne (wine region)
–
Viticultural zones in the Champagne region
Champagne (wine region)
–
Statue of
Pope Urban II in Champagne
Champagne (wine region)
–
Champagne wine
22.
Phenolics (wine)
–
These compounds include phenolic acids, stilbenoids, flavonols, dihydroflavonols, anthocyanins, flavanol monomers and flavanol polymers. This large group of natural phenols can be separated into two categories, flavonoids and non-flavonoids. Flavonoids include the anthocyanins and tannins which contribute to the color, the non-flavonoids include the stilbenoids such as resveratrol and phenolic acids such as benzoic, caffeic and cinnamic acids. The natural phenols are not evenly distributed within the fruit, phenolic acids are largely present in the pulp, anthocyanins and stilbenoids in the skin, and other phenols in the skin and the seeds. During the growth cycle of the grapevine, sunlight will increase the concentration of phenolics in the grape berries, the proportion of the different phenols in any one wine will therefore vary according to the type of vinification. Red wines will also have the phenols found in white wines, anthocyanins react with catechins, proanthocyanidins and other wine components during wine aging to form new polymeric pigments resulting in a modification of the wine color and a lower astringency. Average total polyphenol content measured by the Folin method is 216 mg/100 ml for red wine and 32 mg/100 ml for white wine, the content of phenols in rosé wine is intermediate between that in red and white wines. In winemaking, the process of maceration or skin contact is used to increase the concentration of phenols in wine, phenolic acids are found in the pulp or juice of the wine and can be commonly found in white wines which usually do not go through a maceration period. The process of oak aging can also introduce phenolic compounds into wine, most wine phenols are classified as secondary metabolites and were not thought to be active in the primary metabolism and function of the grapevine. However, there is evidence that in some plants flavonoids play a role as regulators of auxin transport. They are water-soluble and are secreted into the vacuole of the grapevine as glycosides. Vitis vinifera produces many phenolic compounds, there is a varietal effect on the relative composition. In red wine, up to 90% of the phenolic content falls under the classification of flavonoids. These phenols, mainly derived from the stems, seeds and skins are often leached out of the grape during the period of winemaking. The amount of phenols leached is known as extraction and these compounds contribute to the astringency, color and mouthfeel of the wine. In white wines the number of flavonoids is reduced due to the contact with the skins that they receive during winemaking. There is on-going study into the benefits of wine derived from the antioxidant. Within the flavonoid category is a known as flavonols, which includes the yellow pigment - quercetin
Phenolics (wine)
–
The phenolic compounds in Syrah grapes contribute to the taste, color and mouthfeel of the wine.
Phenolics (wine)
–
The process of
maceration or extended skin contact allows the extraction of phenolic compounds (including those that form a wine's color) from the skins of the grape into the wine.
Phenolics (wine)
–
Tempranillo has a high pH level which means that there is a higher concentration of blue and colorless anthocyanin pigments in the wine. The resulting wine's coloring will have more blue hues than bright ruby red hues.
Phenolics (wine)
–
Fermenting with the stem, seeds and skin will increase the tannin content of the wine.
23.
Skin contact
–
Maceration is the winemaking process where the phenolic materials of the grape—tannins, coloring agents and flavor compounds—are leached from the grape skins, seeds and stems into the must. To macerate is to soften by soaking, and maceration is the process by which the red wine receives its red color, since 99% of all grape juice is clear-grayish in color. In the production of wines, maceration is either actively avoided or allowed in very limited manner in the form of a short amount of skin contact with the juice prior to pressing. This is more common in the production of varietals with less natural flavor and body structure like Sauvignon blanc, for Rosé, red wines grapes are allowed some maceration between the skins and must, but not to the extent of red wine production. The process of maceration begins, to varying extent, as soon as the skins are broken. Temperature is the force, with higher temperatures encouraging more breakdown and extraction of phenols from the skins. Maceration continues during the period, and can last well past the point when the yeast has converted all sugars into alcohol. The process itself is a one with compounds such as the anthocyanins needing to pass through the cell membrane of the skins to come into contact with the wine. This process seems to slow once the wine reaches a level of 10%. Throughout the fermentation process, carbon dioxide is released as a byproduct of the conversion of sugar into alcohol, the carbon dioxide seeks to escape from the must by rising to the top of the mixture, pushing the grape skins and other materials to the top as well. This forms what is known as a cap that is visible on top of the fermentation vessel and this process of pumping over or punching down the cap is done often throughout the fermentation process, depending on the extent of maceration the winemaker desires. An efficient and modern method of maceration is the process in which compressed air or gas is sequentially injected into the juice. Depending on the varietal, the process of maceration can help bring out many flavors in the wine that would otherwise be lacking and it can enhance the body and mouthfeel for many wines, as well as strengthen the color. Greater extraction can add to the complexity and life expectancy of the wine by developing more complex tannins that will soften over a period of time. With these benefits does come the risk of developing various wine faults, too much extraction can also increase the harshness of some tannins to where the wine is not very approachable to most wine drinkers. One classical method of maceration is grape stomping or pigeage, where grapes are crushed in vats by barefoot workers. This technique was popular in the production of Burgundy wines in the 1970s & 1980s but there is some debate among oenologists about the overall benefits to. Carbonic maceration is the fermentation of whole clusters of grapes in an atmosphere saturated with carbon dioxide
Skin contact
–
Cabernet Sauvignon musts interact with the skins during fermentation to add color,
tannins and flavor to the wine.
Skin contact
–
The "cap" of grape skins being "punched down" to maximize maceration.
24.
Color (wine)
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The color of wine is one of the most easily recognizable characteristics of wines. Color is also an element in wine tasting since heavy wines generally have a deeper color, the accessory traditionally used to judge the wine color was the tastevin, a shallow cup allowing one to see the color of the liquid in the dim light of a cellar. The color is an element in the classification of wines, the color of the wine mainly depends on the color of the drupe of the grape variety. The Teinturier grape is an exception in that it also has a pigmented pulp, the blending of two or more varieties of grapes can explain the color of certain wines, like the addition of Rubired to intensify redness. Red drupe grapes can produce white wine if they are quickly pressed, the color is mainly due to plant pigments, notably phenolic compounds. The color depends on the presence of acids in the wine, the use of a wooden barrel in aging also affects the color of the wine. The color of a wine can be due to co-pigmentation of anthocyanidins with other non-pigmented flavonoids or natural phenols. Rosé wine is made by the practice of saignée or by blending a white wine with a red wine, the presence of a complex mixture of anthocyanins and procyanidins can increase the stability of color in wine. As it ages, the wine undergoes chemical reactions involving acetaldehyde of its pigments molecules. The newly formed molecules are stable to the effect of pH or sulfite bleaching. The new compounds include pyranoanthocyanins like vitisins, pinotins and portosins, malvidin glucoside-ethyl-catechin is a flavanol-anthocyanin adduct. Flavanol-anthocyanin adducts are formed during wine ageing through reactions between anthocyanins and tannins present in grape, with yeast metabolites such as acetaldehyde, acetaldehyde-induced reactions yield ethyl-linked species such as malvidin glucoside-ethyl-catechin. This compound has a better stability at pH5.5 than malvidin-3O-glucoside. When the pH was increased from 2.2 to 5.5, the exposure of wine to oxygen in limited quantities can be beneficial to the wine. Castavinols are another class of colorless molecules derived from colored anthocyanin pigments, in model solutions, colorless compounds, such as catechin, can give rise to new types of pigments. The first step is the formation of colorless dimeric compounds consisting of two units linked by carboxy-methine bridge. This is followed by the formation of xanthylium salt yellowish pigments and their ethylesters, resulting from the dehydration of the colorless dimers, the loss of a water molecule takes place between two A ring hydroxyl groups of the colorless dimers. The main colors of wine are, Gray, as in vin gris, orange, as in orange wine, a white wine that has spent some time in contact with its skin, giving it a slightly darker hue
Color (wine)
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Judging color is the first step in
tasting a wine
Color (wine)
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Three glasses of wine colors (from left to right),
white,
red,
rosé and
aged white wine with
brown color.
Color (wine)
Color (wine)
25.
PH
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In chemistry, pH is a numeric scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the concentration, measured in units of moles per liter. More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion, solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, at pH7, being neither an acid nor a base, contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively. The pH scale is traceable to a set of standard solutions whose pH is established by international agreement, the pH of aqueous solutions can be measured with a glass electrode and a pH meter, or an indicator. In the first papers, the notation had the H as a subscript to the p, as so. The exact meaning of the p in pH is disputed, but according to the Carlsberg Foundation and it has also been suggested that the p stands for the German Potenz, others refer to French puissance. Another suggestion is that the p stands for the Latin terms pondus hydrogenii, potentia hydrogenii and it is also suggested that Sørensen used the letters p and q simply to label the test solution and the reference solution. Currently in chemistry, the p stands for decimal cologarithm of, PH is defined as the decimal logarithm of the reciprocal of the hydrogen ion activity, aH+, in a solution. P H = − log 10 = log 10 For example and this definition was adopted because ion-selective electrodes, which are used to measure pH, respond to activity. For H+ number of electrons transferred is one and it follows that electrode potential is proportional to pH when pH is defined in terms of activity. The reference electrode may be a silver chloride electrode or a calomel electrode, the hydrogen-ion selective electrode is a standard hydrogen electrode. Reference electrode | concentrated solution of KCl || test solution | H2 | Pt Firstly, the cell is filled with a solution of hydrogen ion activity. Then the emf, EX, of the cell containing the solution of unknown pH is measured. PH = pH + E S − E X z The difference between the two measured emf values is proportional to pH and this method of calibration avoids the need to know the standard electrode potential. The proportionality constant, 1/z is ideally equal to 12.303 R T / F the Nernstian slope, to apply this process in practice, a glass electrode is used rather than the cumbersome hydrogen electrode. A combined glass electrode has a reference electrode. It is calibrated against buffer solutions of hydrogen ion activity
PH
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Lemon juice tastes sour because it contains 5% to 6%
citric acid, which has a pH of 2.2.
PH
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Chart showing the variation of color of universal indicator paper with pH
PH
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pH values of some common substances
26.
Titratable acidity (wine)
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The acids in wine are an important component in both winemaking and the finished product of wine.9 and 3.9. Generally, the lower the pH, the higher the acidity in the wine, however, there is no direct connection between total acidity and pH. Three primary acids are found in grapes, tartaric, malic and citric acids. During the course of winemaking and in the wines, acetic, butyric, lactic and succinic acids can play significant roles. Sometimes, additional acids, such as ascorbic, sorbic and sulfurous acids, are used in winemaking, in most plants, this organic acid is rare, but it is found in significant concentrations in grape vines. Along with malic acid, and to a lesser extent citric acid, the concentration varies depending on grape variety and the soil content of the vineyard. Some varieties, such as Palomino, are disposed to having high levels of tartaric acids, while Malbec. During flowering, high levels of acid are concentrated in the grape flowers. Less than half of the tartaric acid found in grapes is free standing, during fermentation, these tartrates bind with the lees, pulp debris and precipitated tannins and pigments. While some variance among grape varieties and wine regions exists, generally half of the deposits are soluble in the alcoholic mixture of wine. The crystallization of these tartrates can happen at unpredictable times, and in a bottle may appear like broken glass. Winemakers will often put the wine through cold stabilization, where it is exposed to temperatures below freezing to encourage the tartrates to crystallize, malic acid, along with tartaric acid, is one of the principal organic acids found in wine grapes. It is found in nearly every fruit and berry plant, but is most often associated with green apples and its name comes from the Latin malum meaning “apple”. In the grape vine, malic acid is involved in processes which are essential for the health. Its chemical structure allows it to participate in reactions that transport energy throughout the vine. Its concentration varies depending on the variety, with some varieties, such as Barbera, Carignan and Sylvaner. The levels of acid in grape berries are at their peak just before veraison. As the vine progresses through the stage, malic acid is metabolized in the process of respiration
Titratable acidity (wine)
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While normally clear, tartaric crystals (pictured) can be dyed the color of the wine in which it has been saturated.
Titratable acidity (wine)
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Malic and tartaric acid are the primary acids in wine grapes.
Titratable acidity (wine)
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Riesling from cool climate wine regions, such as the
Rheingau in
Germany will have more malic acid and green apple notes than wines from warmer regions.
Titratable acidity (wine)
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Chardonnay is often put through malolactic fermentation when it is being oaked. The softer, milky lactic helps contribute to a creamier mouthfeel in the wine.
27.
Volatile acidity
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A wine fault or defect is an unpleasant characteristic of a wine often resulting from poor winemaking practices or storage conditions, and leading to wine spoilage. Many of the compounds that cause wine faults are already present in wine. In fact, depending on perception, these concentrations may impart positive characters to the wine, however, when the concentration of these compounds greatly exceeds the sensory threshold, they replace or obscure the flavors and aromas that the wine should be expressing. Ultimately the quality of the wine is reduced, making it less appealing, outside of the winery, other factors within the control of the retailer or end user of the wine can contribute to the perception of flaws in the wine. In wine tasting, there is a big distinction made between what is considered a flaw and a fault, Wine flaws are minor attributes that depart from what are perceived as normal wine characteristics. These include excessive sulfur dioxide, volatile acidity, Brettanomyces or Brett aromas, the amount to which these aromas or attributes become excessive is dependent on the particular tastes and recognition threshold of the wine taster. Generally, a wine exhibiting these qualities is still considered drinkable by most people, however, some flaws such as volatile acidity and Brettanomyces can be considered a fault when they are in such an excess that they overwhelm other components of the wine. Wine faults are generally major attributes that make a wine undrinkable to most wine tasters, examples of wine faults include acetaldehyde, ethyl acetate and cork taint. The vast majority of wine faults are detected by the nose, however, the presence of some wine faults can be detected by visual and taste perceptions. For example, premature oxidation can be noticed by the yellowing and browning of the wines color, the sign of gas bubbles in wines that are not meant to be sparkling can be a sign of refermentation or malolactic fermentation happening in the bottle. Unusual breaks in the color of the wine could be a sign of excessive copper, a wine with an unusual color for its variety or wine region could be a sign of excessive or insufficient maceration or as well as poor temperature controls during fermentation. Tactile clues of potential wine faults include the burning, acidic taste associated with volatile acidity that can make a wine seem out of balance. The oxidation of wine is perhaps the most common of wine faults, as the presence of oxygen, oxidation can occur throughout the winemaking process, and even after the wine has been bottled. Anthocyanins, catechins, epicatechins and other present in wine are those most easily oxidised. Apart from phenolic oxidation, the ethanol present within wine can also be oxidised into other compounds responsible for flavour, acetaldehyde is an intermediate product of yeast fermentation, however, it is more commonly associated with ethanol oxidation catalysed by the enzyme ethanol dehydrogenase. Acetaldehyde production is associated with the presence of surface film forming yeasts and bacteria, such as acetic acid bacteria. The sensory threshold for acetaldehyde is 100-125 mg/L, beyond this level it imparts a sherry type character to the wine which can also be described as green apple, sour and metallic. Acetaldehyde intoxication is also implicated in hangovers, acetic acid in wine, often referred to as volatile acidity or vinegar taint, can be contributed by many wine spoilage yeasts and bacteria
Volatile acidity
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The oxidation of ethanol
