By Benjamin Goodin

As I was growing up, my parents trained me to conserve and re-use as much as possible.  To the endless consternation of family members, my mother stocked our refrigerator full of optical illusions: butter dishes filled with leftovers, coffee cans brimming with fat drippings, and pasta salads sleeping in old Cool Whip containers. This spirit of conservation, bestowed upon me by my frugal parents, has expanded to include a mini composting bucket for vegetable scraps and eggshells underneath my kitchen sink. I’ve been known to occasionally preserve the syrup from canned fruit to sweeten tea and adult beverages, so when I started seeing the internet light up with the idea of using the fluid that canned beans swim in, I took interest.

The idea of cooking with strained bean liquid does not sound very appetizing at first, but “aquafaba” (a playful Latin combination that means “bean-water”) has sparked interest in more than just penny pinchers like myself. In fact, the trend has gained enough momentum to merit a nutritional study of aquafaba. And vegetarian, vegan, and just plain curious cooks are experimenting with a substance that most of us have merely washed down our drains.

The favored variety of aquafaba is strained from the liquid of canned chickpeas because it does not maintain any strong bean flavors. However, any bean liquid will work, even that from canned peas. Other suggested candidates for low bean-flavor aquafaba are the liquids from canned butterbeans and white northern beans. Low-salt varieties are preferred, and, if you are looking to eat organically, check the preservative content on the label before straining the bean liquid. Alternatively, you can be completely certain of the content of the liquid by preparing the beans yourself from their dried form.

Aquafaba is extremely useful because it is a great substitute for eggs. Not only does it work cleverly around egg allergies, but it also contains protein, starches, and surprisingly few calories — only three to five per tablespoon.  Being a plant-based alternative, aquafaba contains no cholesterol and is vegetarian, vegan, and celiac-friendly (gluten-free). When substituting aquafaba for eggs, use the following ratios: three tablespoons per whole egg, two for egg whites, and a single tablespoon when a recipe calls for a yolk.

The real charm of aquafaba is its utility; it is perhaps even more versatile than the eggs that it replaces! The primary use of aquafaba as an egg substitute is in baking. Its properties are complex enough that it can act like both yolks and whites. Apparently, the chemical makeup of aquafaba makes it perfect for creating fluffy textures and moist baked goods after it has been whisked. It also finds use in creamy frostings, sauces, and other emulsions. Aquafaba is a prime candidate for gelling as well because it contains plenty of starches. Experimenting cooks have created aquafaba cheese from the liquid, raw cashews, and tapioca starch.  Love meringue? A variety of Aquafaba meringues can be whisked up easily as a substitute for the traditional egg-white variety. Essentially, if a recipe contains eggs, the bean liquid can stand in nicely.

Aquafaba is an emerging health-food trend.  It is not yet sold separately from the beans that it is used to preserve, but if it continues to capture the imagination of creative cooks, it probably won’t be long before you can pick it up at your local grocer. Until then, it comes free with your favorite can of beans, or it can be homemade by boiling up some legumes for a clean-eating variety of bean water. In its canned form, aquafaba lasts as long as the beans, which is probably until the apocalypse. Decanted, the liquid lasts a few days, but can easily be frozen without losing nutritional value or any of its unique properties. If you decide to freeze some for future use, try using an ice cube tray to divide it into pre-measured quantities for no-measuring, no-guesswork cooking.

Aquafaba Chocolate Mousse

Ingredients:
3.5 oz    vegan or regular chocolate, either dark or milk chocolate
1 can    chickpeas
1 tsp    cream of tartar
Sweetener of choice (optional): either a drizzle of maple syrup,
a good pinch of stevia or a few teaspoons of sugar

Instructions:

1. Open a can of chickpeas. Pour the brine (aquafaba) into a medium-sized bowl and save the chickpeas (I like eating them in a salad, or you could make some hummus).
2. Using a electric mixer, beat the aquafaba for about 10-15 minutes, or until stiff peaks begin to form. The brine will act exactly like egg whites: first it becomes white and foamy, then the texture becomes denser until, after a while, it will become stiff enough that you can tip the bowl upside down and the whisked aquafaba remains in place.
3. Add the cream of tartar to this in the last minutes of beating. Place the beat aquafaba in the fridge.
4. Melt the chocolate in a heat-proof bowl over a pan of simmering water. After a few minutes, the chocolate should be melted; stir with a wooden spoon to make it silky and glossy. Set aside to cool; if you are using any sweetener, add it now.
5. When the chocolate is cooled but still melted (you don’t want it to be too pasty — on the other hand, warm chocolate will ruin the recipe) add a dollop of the whisked aquafaba. Gently, VERY gently, fold it into the chocolate. Continue this process with the rest of the aquafaba until there is none left. You will notice the mousse will gain a lot of volume. It’s important that you complete this step slowly so as not to beat the air out of the whisked aquafaba.
6. Pour the mousse into 4 little pots or cups, and leave in the fridge for a couple of hours to set before serving.

^{Recipe courtesy of Clemence Moulaert, curator of The Vegan Cookie Fairy blog (thevegancookiefairy.com). Full electronic text of the recipe can be found at thevegancookiefairy.com/2015/08/09/vegan-aquafaba-chocolate-mousse-3-ingredients/.}