Whey is the liquid left behind when milk separates into curds and whey during cheese making, or when you strain yogurt. It's mostly water, but it also carries some lactose and whey protein.
Sweet whey and acid whey
- Sweet whey comes from cheeses made with rennet. It has a mild, slightly sweet taste, so it's the more versatile one.
- Acid (sour) whey comes from cheeses and yogurt made with lemon or vinegar. It can be sharp, so it's best used in place of water in doughs and baked goods.
Ways to use it
The easiest way to use whey is as a straight swap for a liquid you were going to use anyway. Here are four swaps that work without changing the rest of the recipe.
Rice and other grains
Use whey in place of the water, 1:1, and cook the rice the way you normally do. Oats, polenta and couscous work the same way.
Pizza dough
Swap whey for the water in a simple pizza dough, same amount, warmed. Here is the whey pizza dough recipe I use.
Pancakes and waffles
Use whey for the milk or water in the batter, same amount. If your recipe calls for buttermilk, acid whey is the closest swap.
Soups and smoothies
For soup, use whey in place of the water, 1:1, the same as with rice. For a smoothie, blend a cup into your usual recipe in place of milk or water.
Whey keeps best in the fridge, and you can freeze it in cubes or small containers so you can pull out just what a recipe needs. Use it quickly once thawed.
One heads-up: because whey contains lactose, take extra care if you're lactose intolerant.