Emulsifying: the basics

In short: Emulsifying means distributing two normally immiscible liquids, like oil and water, finely enough to create a stable, creamy mixture. Mayonnaise and vinaigrette are classic examples of successful emulsifying in the kitchen.

In more detail: In emulsifying, tiny oil droplets are dispersed within the water phase or vice versa, which would otherwise separate again on its own without a helping agent.

In detail

• Emulsifiers: Substances like egg yolk, mustard, or lecithin have molecular parts compatible with both fat and water, holding the phases together.
• Mayonnaise as an example: Slowly stirring oil into egg yolk while whisking constantly creates a stable emulsion with a creamy texture.
• Temperature control: Too large a temperature difference between ingredients can cause an emulsion to break and the mixture to separate.
• Speed of mixing in: Oil should always be added slowly and in small amounts so the droplets can distribute evenly.
• Fixing a broken emulsion: If a mixture separates, it often helps to slowly work a spoonful of the separated mixture back into fresh egg yolk.
• Butter as an emulsion: Butter too is a natural emulsion of fat and water, stabilized by milk proteins.
• Salad dressings: A vinaigrette of oil and vinegar usually separates quickly again without an emulsifier, but can be briefly emulsified by vigorous shaking (sosse-binden-und-saucen-grundlagen).