Emulsion

A smooth mixture of two liquids that normally do not mix, such as fat and water, with one spread through the other as tiny droplets.

Emulsion: a whisk in a bowl turning oil and egg yolk into a thick, glossy, creamy emulsion, with a small jug of oil beside it
  • Food science and baking chemistry

Also called: emulsification, emulsifying

Emulsions are everywhere in baking: buttercream, ganache, hollandaise-like sauces, cake batters and mayonnaise. Emulsifiers help keep the droplets apart; egg yolks contain lecithin, which is why they are so useful, and the milk proteins in cream and butter help too.

An emulsion breaks when the ingredients are too cold or too warm, or when one is added too fast: the mixture looks curdled, greasy or split. Gentle warming, slower adding or brief blending usually brings it back.

Related entries

Sources

Written by VanillaGoods in our own words from these sources. Last reviewed October 15, 2026.

  1. Emulsions: When Oil and Water Do Mix, Institute of Food Technologists (Food Technology magazine)
  2. Getting Immersed in Emulsions, Institute of Food Technologists (Food Technology magazine)
  3. Functions of Baking Ingredients (NF94-186), University of Nebraska-Lincoln Extension