Homogenization is a process used to mix and disperse milk fat globules in order to prevent milk from separating and give it a more homogeneous texture. During homogenization, milk is subjected to high pressure to break up the fat globules. When the fat droplets become very small (less than 2 microns), they are covered by a membrane composed of lipids and proteins, as well as by casein micelles. This membrane prevents the fat from collecting at the surface of the milk and allows its permanent dispersion in a very fine emulsion.

Homogenization is purely a mechanical process and does not affect the nutritional value of milk, but rather modifies its sensory characteristics. Homogenized milk has a creamier, more uniform texture, a whiter color, and a longer shelf life compared to non-homogenized milk. Homogenization also prevents a layer of cream from forming in the milk, which made homogenized milk popular with consumers as early as the 1920s. Homogenization does not affect the taste of milk or whats actually in it.

Its worth noting that homogenization is a separate process from pasteurization, which is used to kill potential bacteria in milk. While its not necessary for homogenized milk to be pasteurized and vice versa, most commercial brands make their milk undergo both processes. Some small dairy farms choose not to homogenize their milk, as they believe it affects the flavor and texture of the milk.