Whey is the liquid remaining after milk has been curdled and strained. Whey proteins consist of α-lactalbumin, β-lactoglobulin, serum albumin, immunoglobulins, and proteose-peptones. Because whey contains lactose, it should be avoided by babies who are lactose intolerant. Dried whey contains 65 to 75 percent lactose and 11 to 12 percent protein. Babies can be allergic to whey or other milk proteins (this is an allergy, not lactose intolerance).