Aquafaba

Aquafaba is the liquid drained from a can of chickpeas. Kansas State University explains that the starch and protein in it make it work as a binder, thickener and emulsifier, and that when whipped and stabilized with cream of tartar it looks like egg white foam.

Bakers use it in vegan meringues, macarons, mousses and buttercream, and as an egg replacer in cakes. The same university gives the rule of thumb that 2 tablespoons stand in for one egg white and 3 tablespoons for one whole egg.

Results vary by brand, so many cooks simmer the liquid down first to thicken it before whipping. The foam is whipped until it holds its shape.