For lovers of Indian food, making your own paneer at home provides a sure sign that you've graduated to the ranks of serious aficionados. A simple fresh cheese, it serves as the feature protein in many of the subcontinent's meatless dishes. The proteins that form paneer represent only a small percentage of your milk's volume, so a gallon of milk will leave you with 3 quarts or more of whey after the cheesemaking. It's still nutritious and versatile, and shouldn't just be discarded.
No Ricotta, Unfortunately
Ordinarily, making a batch of ricotta from the leftover whey presents an easy and appealing option. Unfortunately that won't work with the whey from paneer. Although the big jars on the supplements shelf speak of "whey protein" as a single substance, there are actually many proteins in whey. The ones that make ricotta are precipitated from the whey by acid and boiling temperatures, which -- alas -- are the two techniques used to coagulate paneer. Still, the mildly tangy, acidulated whey from paneer has other valid uses.
Whey in Beverages
A highly nutritious beverage in its own right, whey retains plenty of vitamins, minerals and protein, but its flavor isn't especially alluring. Incorporating it into fruit drinks counters that shortcoming, with the bright acidity and rich flavor of lemonade or orange juice masking the faint dairy taste of the whey. Whey won't curdle, as whole milk does, so it's a fine way to add nutritive value to your drink. You can also add whey as part of the liquid in your favorite smoothie or protein shake, lending it an extra kick of fast-acting protein. There's no set percentage to follow, so let your taste buds be your guide.
Whey in Cooking
Whey can boldly go where milk does not, since the proteins that ordinarily would curdle are already removed. That means you can employ it as part of your cooking liquid in almost any setting, in place of water, milk or even stock. Many curry dishes relying on paneer call for whey to be used in their sauce, a natural and frugal choice. Whey lends flavor and body to soup broths, when used in moderation, and in cream or dairy-based soups it can replace most or all of the water you'd normally use.
Whey in Baking
Similarly, whey can be substituted for water, milk or buttermilk in baking. Its effect is most similar to that of buttermilk, lending a faint tang and richness to your baked goods. Paneer whey will react with baking soda, helping raise your goods, but -- because its acidity is more variable -- you might need to add a splash of lemon juice to ensure that your biscuits or muffins reach their full potential loft.