How To Fix A Broken Egg-Based Sauce

Egg sauces — mayonnaise, bernaise, and hollandaise — are notoriously tricky. They're all emulsions, or mixtures of liquids that don't normally play nice. In cooking, emulsions are usually mixtures of fat and water. Egg sauces blend eggs, which are mostly water, with fats like butter or oil. A successful emulsion is more or less stable: It can sit around for a while before the ingredients start to separate. While egg sauces are intimidating, it's possible to make them at home — in fact, hollandaise is one of the 13 sauces that chefs say we should learn to make at home. Just be prepared in case they break. 

Making an emulsion is all about messing up the molecular structure — that's how you get fat and water to mix. Often, it's as simple as maintaining a balance between water and fat. But tinkering around with the molecular structure gets tricky. If you're not careful, the emulsion will break and the protein molecules will clump or curdle. That's not the texture you want, unless you're one of those sickos who enjoy cement mixer shots, the grossest drink you can make.

If you see fat collecting around the edges of the bowl, the sauce is too fatty. Add a tablespoon of the liquid you're using as a base and give it a good whisk. If it's broken completely, you need to create a new emulsion — but don't toss out your sauce. If your sauce is curdled, the new emulsion will help you put it back together.

When you're making a new emulsion, try to use something that'll stabilize the sauce. For egg sauces, you don't need to buy cream of tartar. The best stabilizer is a bit of acid, like lemon, vinegar, or wine. To make the new emulsion, put a teaspoon of lemon juice in a bowl. Whisk in a little bit of the old, broken emulsion. Once you've made a new, stable emulsion, add the old emulsion in a thin, steady stream while you whisk.

Yeah, I know: Acid is scary if you've dealt with curdled dairy before. But while acid will make a dairy sauce curdle, it denatures, or changes the shape of the protein in the egg yolks, and keeps egg-based sauces together. Acid also helps keep the eggs from cooking by raising the point where they start to solidify to 190 degrees Fahrenheit — though ideally, the sauce should be well below that.

Lemon juice is a metaphorical bearnaise bandaid. But there are times when you need to pull the metaphorical plug. It's possible to fix a curdled sauce, but not a scrambled one. If you've accidentally cooked your eggs, it's time to throw the sauce out and try again.