Whey powder

Whey may be regarded as skimmed milk less the casein (protein). It is the liquid fraction obtained when milk is used for cheese production. The casein is coagulated by acids or enzymes and is separated with the fat to form the cheese and this leaves the whey. Whey is rich in lactose and minerals but also includes the serum proteins, the albumins. Depending upon the type of cheese being formed, the whey may be "sweet" (from Cheddar and Swiss type cheeses) or acid (for example, from cream cheeses).

Whey is dried in a similar way to the other milk powders and because of its lower cost is now used extensively in biscuits in place of SMP. The function of whey powder in dough is very similar to SMP. Separation techniques have been developed which have allowed the preparation of lactose, demineralised whey, and whey protein concentrate.

Lactose is used where low sweetness and savoury flavour enhancement is required, but the mineral content of normal whey powder may contribute a salty flavour which is not so pleasant as SMP. Demineralisation reduces this saltiness.