Chapter 22 · Sauces and how they thicken
22.3 Emulsions
A simple whisked vinaigrette does not last. Nothing holds the drops apart, so given time they find each other and the dressing separates back into oil and vinegar. It is a temporary emulsion.
To make an emulsion that stays, you need an emulsifier (emulsifying agent). It bonds with both the oily liquid and the watery one and acts as a bridge between them, like a friend holding each by the hand.
The emulsifiers a cook uses most:
- Egg yolk, the most common, in mayonnaise and hollandaise.
- Casein, a protein found in butter.
- Dry mustard, finely ground.
- Honey and Dijon mustard, which are thick enough to work the same way.
Emulsions can be hard to get right, even for practiced chefs, and knowing what is happening in the bowl makes them easier to control. The fats themselves, and the lecithin in egg yolk, are covered with fats and oils. see chapter 19: Emulsifiers
Sources
This chapter is written from these open textbooks:
- Flavors of the Saucier: Stocks, Sauces and Soups — Zeringue & Thibodeaux, Chef John Folse Culinary Institute, Nicholls StateCC BY-NC-SA 4.0
- The Chemistry of Cooking — Sorangel Rodriguez-Velazquez, LibreTextsCC BY-NC-SA 4.0
- Culinary Foundations — Cheramie & Thibodeaux, Chef John Folse Culinary Institute, Nicholls StateCC BY-NC-SA 4.0
- Food Safety, Sanitation and Personal Hygiene — BC Cook Articulation Committee, BCcampusCC BY 4.0
- Basic Scientific Food Preparation Lab Manual — Dept. of Food Science and Human Nutrition, Iowa State UniversityCC BY-NC-SA 4.0