INFORMATION ON RAISING AGENTS!!
A few different types of raising agents are-
AIR can be a raising agent by beating or folding i.e. incorporating air into the mixture.
CHEMICAL Baking powder, sodium bicarbonate, cream of tartar are some of the chemical raising agents which are used in raising the mixture when baked or cooked.
BIOLOGICAL Yeast is the biological raising agent when added. It helps to raise the mixture.
WATER VAPOUR also helps to raise the mixture when steaming. This happens when flour and liquid are mixed in equal quantities.
EGG acts as a raising agent. When the white of an egg is beaten stiffly and mixed, (as in sponge cakes, meringues) it helps to increase the volume of the mixture.