Milk and Cream Emulsions

Appears in
On Food and Cooking

By Harold McGee

Published 2004

  • About

Cream owes its versatility to its origins in milk. Milk is a complex dispersion whose continuous phase is water, and whose dispersed phases are milkfat in the form of microscopic droplets, or globules, and protein particles in the form of casein aggregates. The droplets are coated with a thin membrane of emulsifiers, both lecithin-like phospholipids and certain proteins; and other noncasein proteins float free in the water. Both the globule membranes and the various proteins are tolerant of heat: so plain milk and cream can be boiled hard without the fat globules coalescing and separating, or the proteins coagulating and curdling.