What's That Weird Foamy Stuff on My Canned Beans?

Canned beans can be a lifesaver for getting quick, easy, and healthy protein into our diets. While cooking good-quality dried beans from scratch is always a great option, sometimes there just isn’t time. Even the bean guru himself, Rancho Gordo founder Steve Sando, acknowledges that canned beans have their place. 

“I think it is 100% a convenience thing,” Sando says. But there’s one thing cooks should take time to do when using canned beans, he says: Rinse them. “The liquid in canned beans is not a pleasant taste or texture, so definitely rinse well before using in recipes,” he says. “Plus, canners use a lot of salt, so it is important to remove that with a good rinse so that your dishes aren’t oversalted.”

What’s Up with That Foam on My Beans? 

When you rinse, though, you may find that your canned beans generate a lot of foam that looks a lot like someone added bubble bath to the colander! Never fear: That foam is actually totally natural and completely safe. But what the heck is it?

During the canning process, legumes from beans to chickpeas leach out some of their starch and proteins into the liquid, which is sometimes called aquafaba. If you do any vegan cooking, you’ll know that aquafaba can be a replacement for egg whites, since it can be whipped into a stable foam for meringues and the like. When it is agitated by the water sprayer, therefore, it starts to create that foam.

Further, beans also contain a compound called saponins, which also create foam when they get agitated in water. (Saponins occur in many plants, some of which are actually used to make soap!) But the saponins in beans are harmless, so while that foam might be a bit shocking when you spot it, just keep rinsing until it is all gone and carry on with your recipe. It’s all natural.

Ready for an easy dinner that starts with a can of beans?  Check out our list of Protein-Packed Dinners with Canned Beans... and don’t forget to rinse!