Table 3 specifies the composition of different types of whey. Regardless of its origin, the main component of whey is the carbohydrate lactose. Lactose accounts for over 70 percent, and therefore by far the majority, of the solid mass. The next-weightiest component is protein, followed by minerals. It is their pH value as well as their individual material compositions that make the different types of whey unique.

The composition of different types of whey
Components	Sweet whey	Acid whey		Casein whey
% Solid mass	6.20	5.70		6.10
% Lactose	4.80	4.60		4.70
% Protein	0.75	0.30		0.50
% Fat	0.05	< 0,01		< 0,01
% Ash	0.60	0.80		0.90
pH value	6.1	4.6		4.4

Sweet whey has the highest concentration of proteins and the lowest concentration of minerals. Its pH value is virtually neutral. Of all the whey products, sweet whey is the one most frequently used as well as being the most important raw ingredient in whey powder and whey derivatives.

Acid whey and casein whey have a pH value of less than 5 and thus are sour to the taste. They contain less protein than sweet whey, but more minerals in the form of calcium phosphate.