Why You Shouldn't Cook Raw Beans In A Slow Cooker

Everybody loves a good food controversy, and perhaps none has been so enduring as the question about the right way to cook dried beans. The main controversy centers on whether or not beans should be soaked before cooking. Take this delicious vegan red beans and rice recipe designed for the Instant Pot; the directions unequivocally call for soaking the dried beans for an hour before cooking. Russ Parsons, writing for the Los Angeles Times in his provocatively titled article, "Don't soak your dried beans! Now even the cool kids agree," obviously takes a different stance.

The developer of the red beans and rice recipe is Miriam Hahn, and she cites two reasons for soaking the beans, explaining, "Soaking the beans helps them cook a little faster and also helps with digestion." Parsons argues differently, writing, "While soaking shortens the unattended cooking time of beans somewhat, the time saved is marginal and there are no other labor-saving benefits. Finally, soaking does absolutely nothing to reduce the gas-producing properties of beans."

What's a home cook to do with this apparently conflicting advice? It depends on how you plan to cook your raw beans. If you're cooking at a higher temperature than a slow cooker uses, you have some flexibility, but as it turns out, there's a definite scientific reason you shouldn't cook raw beans in a slow cooker.

It's all about the lectins

According to the Harvard School of Public Health, lectins are "proteins that bind to carbohydrates," and raw legumes and whole grains have very high levels of lectins. These proteins don't break down in our bodies, and they can cause mild, moderate, or severe gastrointestinal distress. Don't panic, though! Lectins are water soluble, so soaking and high-heat cooking methods will disable them and make them safe to eat. The problem is, "raw beans simmered at low heat such as in a slow-cooker or undercooking the beans will not remove all the lectins."

Slow cookers on the low setting generally reach around 190 degrees F, according to Oven Spot. Chow Line, a project of The Ohio State University, explains that raw kidney beans contain lectins, and that's why the FDA recommends that they be soaked for at least five hours and then boiled at a minimum of 212 degrees F for at least ten minutes. Boiling the beans destroys the toxic lectins, and slow cookers on the low setting just don't get hot enough to make raw beans safe for consumption. Rather than using a slow cooker, try this delicious stovetop recipe for spicy pinto beans.