Forms fat globules. Globule membranes tolerate heat, such that milk and cream
can be heated and boiled. On the other hand, milk fat that has been frozen
easily clumps into grains of butter.
Curd
Casein proteins. Tolerant of heat unless in acidic environments, where
they will coagulate.
Whey
Milk proteins that remains after the curd forms. Also resistant to heat.
Lactose
Milk sugar, giving milk its sweet taste. Often indigestible.
Milk Treatments
Raw Milk
Has a fresh taste that is otherwise altered after pasteurization. Fat-rich
cream will rise to the top when left to stand (creaming).
Pasteurization
Moderate heat treatment that kills microbes and deactivates milk enzymes.
Extends shelf life while minimizing changes in flavor.
Batch Pasteurization
A batch of milk is gently heated and stirred for a good length of time. The most mild method.
High-temperature Short-time (HTST)
Milk is pumped through a heat exchanger, being exposed to more heat for a
brief period of time. Develops a cooked flavor.
Ultra-high Temperature
Milk is heated at a very high temperature almost instantaneously. Becomes more
cooked but is also shelf stable.
Homogenization
Hot milk is pumped at high pressure through small nozzles to decimate the size
of fat globules, preventing creaming.
Low-Fat Milks
Centrifuges separate milk and cream, allowing for milk to be made with different fat content.
(Skim, 1%, 2%, and whole milk at about 3.5%).
