Acid whey, with a pH less than or equal to 5.1, is produced during the manufacture of cottage cheese, ricotta and cream cheeses and has applications in such products as salad dressings and snack foods that require a savory flavor profile.
Sweet whey, with a pH of 5.5 or greater, is created during the manufacture of rennet-coagulated cheese (Cheddar-style and Swiss-style cheese curds).
Whey protein concentrate (WPC) is produced by concentrating, using filtration, the protein components of pasteurized whey and is used to simultaneously enhance protein fortification and functionality of a food product. For instance, WPC with a 75% protein content can be used as a replacement for egg whites. WPC typically contains 34% or more protein.
Whey protein isolate (WPI) is manufactured in a manner similar to WPC, but with a resulting concentration of 90% or more protein.
Reduced-lactose whey has a lactose content of less than 60%; the lactose is removed through filtration, dialysis or precipitation.
Demineralized whey may be created by drying whey that already has been processed to remove a portion of its mineral content via precipitation, ion exchange, electrodialysis or membrane filtration. Reduced-mineral whey cannot contain more than 7% ash.