What is homogenisation?

When untreated milk is stored or left to stand, gravity causes the fat globules in the milk to flocculate (separate by gravity) and naturally rise to form a cream layer at the surface; sometimes this can lead to the formation of a surface layer of congealed cream in refrigerated milk. Homogenisation is a process that prevents flocculation by breaking up the fat globules to a smaller size that can remain suspended evenly throughout the milk, producing a uniform (homogenous) consistency. This is achieved by passing the milk through small holes, under high pressure. Almost all milk available to purchase in Ireland is homogenised.

Extra information:

Homogenisation increases the whiteness of milk because the greater number of smaller fat globules scatter light more effectively.