Understand their importance in creating thick, creamy sauces
Emulsification is a cooking technique that brings two unlikely ingredients together.
The ingredients are usually a fat or oil, like olive oil, and a water-based liquid like broth, vinegar, or water itself.
We all know oil and water don’t mix.
So a good vigorous amount of whisking helps combine these two ingredients until they become one.
So you need an emulsifier to help stabilise the mixture.
But it means it sometimes splits.
You can have emulsions that can create semi-permanent or permanent stability.
For example sauces like béarnaise sauce, hollandaise, mayonnaise, aioli.
Then there are vinaigrettes (oil and lemon), which split but you can add some mustard (the emulsifier) to help stabilise it.
How does emulsification work?
Emulsifiers include egg yolks, butter, cheese, mustard, honey, tomato paste, etc
These emulsifiers coat droplets, keeping them separate from each other, otherwise the droplets would clump together, causing the emulsion to separate.
The emulsifiers molecules have a fat-loving part which sticks to the oil.
And a water-soluble part that sticks to the water.
Bring them all together in the right environment (not too hot, too cold, too fast, etc) and you’ll have a wonderful new sauce.
How to emulsify
To make an emulsion you combine the liquids very, very slowly while beating vigorously.
(I was once tasked with making huge batches of mayonnaise in a hotel kitchen once… I think it was part of my initiation. It put me off mayonnaise for life!).
But you can use a food processor or blender to make life easier rather than hand whisking.
Fixing split emulsions
The key to not splitting your sauce is to combine them slowly and not over too much heat.
But you can save them if you do accidentally have a sauce separate.
Broken hollandaise sauce
Mix a teaspoon of lemon juice and a tablespoon of the broken sauce.
Beat until creamy and then add the rest of the sauce, half a tablespoon at a time, beating until creamy with each addition.
Mix a teaspoon of mustard with a tablespoon of the broken mayonnaise (or one egg yolk plus a little lemon juice).
Beat until creamy, and then add the rest of the broken mayonnaise, one teaspoon at a time.
NB: If mayonnaise becomes oily on the surface, whisk in a tablespoon of water.
This is a temporary emulsion to start with so you’re best to serve immediately after it’s made.
Or shake vigorously in a closed container to mix it together again.
But by adding a teaspoon of mustard, you’ll help combine it for longer.
Food you may not have thought of as emulsifying
Loads of sauces and soups are partial emulsions, thickened by butter or cream at the very end of cooking.
Espresso: the high pressure that forces the water through the ground coffee beans causes the oil from the beans to emulsify with the water – that’s how you get the crema
Pesto: is a partial emulsion. The fresh basil leaves contain water but combined with plenty of olive oil it’s broken down into a thick, creamy paste.
Bouillabaisse: is an emulsified French fish soup. The gelatin from the fish parts, mixed with olive oil help give the soup a creamy consistency.
Do you have any tips for making creamy sauces? Leave a comment, below.