As I mentioned in my previous post (Soy Lecithin: Why is It in Everything?), lecithin will create a foam when whipped into a watery liquid. I thought it might be fun to try this technique on a Caprese salad, which is typically layered tomato, fresh mozzarella, and basil. Here, I substituted the basil with a foam made from fresh basil, water, and soy lecithin. It’s a delicate and beautiful addition to the salad, and would be sure to wow guests at a party! The beauty of the lecithin foam is that it allows the authentic flavor of the ingredients to shine through. Foams made with egg whites or cream bring lots of their own eggy or creamy flavor to the mix. With lecithin, you just get pure basil-y freshness. Yum!
1 cup water
1 cup fresh basil, roughly chopped or torn (reserve some tiny leaves for garnish)
2 grams (g) soy lecithin powder
Salt and pepper, to taste
Fresh mozzarella, sliced
In a large container, whip all ingredients with immersion blender until foamy. It helps to angle the blade so that it peeks above the liquid a bit. I grow a few varieties of fresh basil at home, so I threw in a little Red Rubin and Neapolitan basil in addition to the standard Genovese basil. You can use whatever type you have on hand. You can see what the soy lecithin powder looks like in the right-hand picture.
As you whip, allowing the blades to peek out a bit helps incorporate air into the mix. Just be sure to use a large container that can accommodate the expansion of the foam plus some amount of sloshing. You can see the foam below is growing!
Now, you can start stacking your salad. Start with a slice of tomato and add salt and pepper to taste. Add the mozzarella on top of that. Generously spoon some basil foam onto your salad and garnish with a tiny basil leaf.
A lecithin foam is lighter and less stable as an egg foam or a whipped cream. It should be added to the plate just before serving. As it sits, some of its liquid will begin to seep out, which ends up making a sort of a light basil sauce under the salad. The other cool thing about lecithin foams is that even if it deflates a bit, you can go back and whip it again to get more foam. This makes it easy to dish out a second or third round of party hors d’oeuvres or serve foam all night at a restaurant. Egg foam certainly wouldn’t stand for re-whipping! That’s why lecithin is such an interesting and valuable foaming agent. You can even freeze your foam for another cool effect!
How it works.
As I discussed in the previous post, lecithin is a phospholipid (phospho = phosphate group, lipid = fat), a type of emulsifier. It’s often used in processed foods like chocolate and creamy salad dressings to keep them from separating, but when you whip it into a watery mixture, it will create a delicate foam. Why? Because the phosphate group (aka the head) of any phospholipid molecule is water soluble, meaning it dissolves in water. In contrast, the lipid portion (aka the tail) of any phospholipid is oil soluble, meaning it dissolves in oil. Molecules that like to have half of their body in water and half in oil are quite rare, and they can make interesting things happen in food!
In the case of our foam, here’s what’s going on: We’re adding lecithin to a mixture that is water-based. If you imagine zooming in on our little lecithin molecules, that means their phosphate groups are happy as clams, surrounded by their favorite thing: water. However, those lipid tails are feeling FUSSY. They hate water and would love nothing more than to get the heck out of there. If there was some oil around, they would take cover there immediately, but without any oil in the mix, where can they go to get relief? Air bubbles. As you whip air into the watery mixture, those little lipid tails grab on as a means of escape from the water. In contrast, the phosphate head is happy in the water and doesn’t care a wink to get dragged into an air bubble. As a result, you get lecithin molecules that have their heads sticking out into the water and their tails getting some sweet relief inside the air bubble. This lecithin lining is what keeps the bubbles stable and allows a foam to form.
However, this system won’t work if there’s too much oil present. There is nowhere those lipid tails would rather be than in oil, so if oil’s available, they’ll ignore the air you’re whipping in, and you won’t get a foam. So try this out with your own herb mix, or try simply whipping up some juice into a foam. Just make sure you use a flavorful liquid, since whipping air into it will dilute its flavor.
You can buy soy lecithin powder online in reasonably small quantities. Amazon.com has a variety of sellers, including Bob’s Red Mill, a brand that is occasionally available in grocery stores.