What makes a buttermilk colloids?

Buttermilk is a colloidal suspension, which is a type of mixture in which tiny particles of one substance are dispersed throughout another substance. In the case of buttermilk, the dispersed particles are casein proteins and fat globules, which are surrounded by a liquid phase that is mostly water. The casein proteins and fat globules are stabilized by electrostatic repulsion, which prevents them from clumping together and settling out of the liquid.

The colloidal nature of buttermilk gives it its characteristic smooth and creamy texture. The casein proteins and fat globules scatter light, which gives buttermilk its opaque appearance. The electrostatic repulsion between the particles also prevents them from coalescing, which means that buttermilk does not separate into layers of cream and water.

Buttermilk is also a good source of nutrients, including protein, calcium, and vitamin B12. It is often used in baking, as it can add flavor and richness to baked goods. Buttermilk can also be used to make pancakes, waffles, and other breakfast foods.