What Exactly Is Whey?

Separating curds and whey from cheese mix

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"Little Miss Muffet sat on a tuffet, eating her curds and whey; along came a spider, who sat down beside her and frightened Miss Muffet away"

You've probably heard this nursery rhyme many times, but do you know what whey is exactly? Whey (pronounced WAY) is one of the two main proteins in milk. It is a derivative of milk and is the liquid that is expelled from cheese curds during the cheesemaking process.

How Whey is Formed

When making cheese, the first step is to add a starter culture to the milk. Once the culture begins to thicken the milk, rennet is added to encourage coagulation further. As the milk coagulates, curds form. The curds are then cut, so they expel moisture, which is the whey. When making soft cheeses, the curds are cut into large pieces; for harder cheeses, the curds are cut into tiny pieces. The smaller a curd is, the more liquid, or whey, it releases. Smaller curbs will remove more moisture and result in hard cheese.

How Whey is Used

Sometimes, whey is discarded after the cheesemaking process, which is a shame because it's full of protein and nutrients. According to Steven Jenkins in The Cheese Primer, a key cheese resource, another reason not to discard whey is for environmental reasons. When poured down the drain, discarded whey can increase the number of algae in sewers and rivers. Luckily, whey can be used for other things.

Whey can be fed to animals, be used to make other dairy products and foods, or be processed into a concentrated form and added to protein powder, protein bars, or processed foods as "whey proteins." Some specific ways to use fresh whey at home include:

  • Make ricotta. Traditionally, ricotta was always made from whey, not milk. In Italian, Ricotta means "recooked" because the cheese is a product made from milk that has already gone through the cheesemaking process. Italian ricotta cheese is usually made from whey derived from sheep's milk and American ricotta cheese is typically made from whey derived from cow's milk.
  • Use whey In place of water or milk in recipes. Replace whey as the liquid ingredient in bread and other pastries, as well as savory recipes. You can also use whey instead of water to boil pasta and rice.
  • Use whey when you need to soak grains. Before cooking grains, you may want to soak them to help break down the phytic acid and allow for proper absorption and better digestion. When soaking grains, you need warm water plus an acidic medium such as whey. You can also use whey to soak steel cut oats overnight.
  • Add whey to smoothies. Since whey is a milk protein, by adding whey to your smoothies you are boosting the amount of protein in your blended drink.

    How to Get Whey

    If you want to get your hands on some fresh whey, then try making cheese at home. Some types of cheese to try are mozzarella and goat cheese. If you make homemade yogurt and thicken it by letting it drain in a cheesecloth, you can use the "yogurt whey" in the same manner that cheese whey is used.