The greatest care should be exercised in the cooking of albumin.

Albuminous matter is of various kinds and is found in animal and vegetable substances. Some are liquid, some are solid. Coagulation is one of the properties of albumin. Heat coagulates nearly all albuminous substances. The albumin in egg and milk should be subjected to slow, even temperature.

The albumin in egg, when subjected to high temperature, will become hard and tough. For example, a custard that has overcooked by too high a temperature becomes a hard, solidified mass, allowing the watery substances to separate; but if subjected to low temperature it will be soft and creamy. The albumin in meat also hardens on exposure to heat. In cooking a choice, tender cut of meat, it is essential to subject it to intense heat in order to harden the albumin on the outside. This will form a hard surface and will help to retain the good juice in the meat.

Albuminous substances, if cooked at a temperature below boiling, will always be soft. When cooked at a temperature of 212 degrees the albumin is hard and tough.

The effect of heat on albuminous substances is not only to change the texture, but also to develop the flavor.

The purest form of albumin is found in the white of egg. The albuminous substances are classified as protein foods.