Where is the Protein in Whey?

Monica Reinagel, MS, LD/N, CNS,
January 5, 2011

Q. In a recent tip, you explained that whey is mostly water and that it is low in protein. How, then, do they produce whey protein powders that are so high in protein?

A. Liquid whey is about 93% water by weight, 5% milk sugar, 1% protein, and half a percent each of fat and minerals. To make whey protein powder, liquid whey is filtered to remove most or all of the fat and milk sugars. It's then dehydrated to remove the water, leaving just the protein.  Depending on how pure the protein powder is, it might take 11 gallons of liquid whey to produce a one-pound can of whey protein powder. But seeing as whey is a by-product of cheese-making, there seems to be no shortage.  Nice that it doesn't get thrown away!

Whey image courtesy of Shutterstock