Paneer, also known as panir, is a fresh acid-set cheese common in the cuisine of the Indian subcontinent made from full-fat buffalo milk or cow milk. It is a non-aged, non-melting soft cheese made by curdling milk with a fruit- or vegetable-derived acid, such as lemon juice.

Curd is obtained by coagulating milk in a sequential process called curdling. It can be a final dairy product or the first stage in cheesemaking. The coagulation can be caused by adding rennet, a culture, or any edible acidic substance such as lemon juice or vinegar, and then allowing it to coagulate. The increased acidity causes the milk proteins (casein) to tangle into solid masses, or curds. Milk that has been left to sour will also naturally produce curds, and sour milk cheeses are produced this way.