The Struggle:
Just because an ingredient is labeled as a foaming ingredient does not mean that it’ll foam everything. Some ingredients foam water-based liquids and others foam fat based liquids. How do these ingredients differ, and how are they the same? What ingredients can you use to make foams from fat if you can’t use the same ones used with water? What happens if there is a small amount of fat in my water based foam? All these questions matter when developing a foam recipe. So in this article we’d like to clear up some of these questions and help you make the best foams when fat has entered the equation.
“ How can I make foams with fat?”
A Different Approach
Fat can be the death of a foam recipe. In a water based liquid a small amount of fat weakens the surface tension and causes the little bubbles to pop. This fat can either come from the ingredient used or it could be an errand fat left on the inside of a bowl that you were using. What are the most common culinary foams is meringue. When cracking the eggs you must make sure that no yolk drips into the whites. This small amount of fat present in the egg whites will cause the meringue to now hold its structure. The same thing happens with other foaming ingredients. The best thing you can do is make sure you’re using a liquid that contains no fat and all of your equipment is perfectly cleaned. With that being said some ingredients will still make a foam. But the structure of the foam will be very weak and begin to dissipate quickly. But this brings us nicely into an ingredient with the ability to make foams out of pure fat.
In order to make a foam when using fat you will need to start with a flavorful fat. It could be as simple as olive oil or chili oil. An ingredient known as mono & diglycerides can be added to a fat. The mono and diglycerides thicken the fat at room temperature which allows it to have structure for the air when foaming. Mono and diglycerides should be added to the recipe in the ratio of 8–10% to the total weight of the fat. In order to incorporate the mono and diglycerides you will need to heat the fat to 140°F. This foam will not be able to be made as a typical lacy foam. You will only be able to create a dense foam by placing this in a whipping siphon and charging it with N2O. The best thing about this phone is that you can pretty much use it indefinitely once it is in the whipping siphon. You can check out our recipe below for a Updated Niçoise Salad with Black Olive Foam. So the next time you’re looking to make a foam make sure that your water base foam is completely free of fat in your fat based foam is using mono & diglycerides. And until next time keep cooking!