Whey refers to the watery part of milk that has been strained after the milk has curdled. It can be produced from the milk of just about any milk producing mammal. It should be noted that there have been attempts at creating vegan compliant whey supplements. Technically speaking, there are two types of whey: there is sweet whey and there is acid whey. In terms of composition, they are nearly identical. The main difference comes from the amount of fat generally present, but it’s not a big difference either.

Sweet whey is whey produced as a byproduct of the production of hard types of cheese with rennet such as cheddar, gruyere, gouda, asiago, etc.. Acid whey, which has the appetizing name of sour whey, is the byproduct of producing sour/acidic dairy products such as different types of strained yogurts. You may also know these types of yogurts as Greek yogurt, which have been strained to remove most of the whey proteins. 

Yes, whey isn’t a term that makes no sense at all. Whey proteins can refer to the proteins found in whey. These proteins include such fun names like beta-lactoglobulin and alpha-lactalbumin. For an even more granular breakdown of what whey proteins consist of, they have been found to have high levels of the amino acid leucine. 

For those of you who don’t know, leucine is considered an essential amino acid, meaning that, while leucine is essential to our survival, humans are not capable of producing said amino acid from scratch at a sufficiently fast rate that we can survive off of that. As a result, the leucine humans need must come from their diet. Among other items, leucine helps to stimulate protein synthesis, so they are often part of training regimens.

Yes, that is why there are whey protein supplements and people that swear up and down by them. However, other people that may swear up and down about the merits of whey include bakers. You can replace skim milk in some recipes with whey. Additionally, whey can be used to make creams, butters, and a variant of cream of tartar. 

As recently as 2015, there has also been medical interest in the use of whey proteins in the treatment of different ailments, primarily type-2 diabetes. This paper does outline some of the ideas about how to go about this. However, as you already know, definite dosage of whey proteins required to achieve the desired results has yet to be determined. 

For those of you who want a more trivial fun fact, here’s one: whey is an ingredient in the carbonated drink Rivella.