Everyone loves a good food controversy,
but the biggest throwdown might be the most unexpected one: What's the right way
to cook dried beans? And where exactly does your slow cooker fit into this whole thing?
At the center of the disagreement is the
question of whether or not beans should be soaked 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 hard
stance against the soak. On the other side of the argument is recipe developer Miriam Hahn,
and she cites two reasons for soaking the beans, saying:
Parsons thinks differently, arguing:
What's a home cook to do with this apparently conflicting advice? Getting
to an answer means digging a bit deeper into the science, and that starts with lectins.
Lectins are proteins that bind to carbohydrates, and raw legumes and whole grains have very
high levels of lectins. Sometimes our bodies have difficulty breaking down
these proteins effectively, which can cause mild to severe gastrointestinal distress.
While lectins may sound like something we should just avoid altogether, let us
offer a more nuanced understanding of them. The common flour binder gluten is a lectin,
and it's certainly a substance some people must carefully consume or avoid altogether.
Phytohaemagglutinin, or PHA, is the lectin that's present in high levels in raw beans,
among other things. And while these two lectins can produce an inflammatory immune response,
research suggests that lectins have health benefits as well, perhaps even cancer-fighting
properties, for people who can tolerate them. And foods naturally high in lectins often
have lots of beneficial things in them, like vitamin B, healthy fats, fiber, and protein.
The key for the lectin-rich foods that are good
for us is safely processing them by cooking, sprouting,
or fermenting the foods to reduce the lectin content to a level that's safe for consumption.
So circling back to the debate, our guts certainly need help breaking down lectins,
and there are a few things that can do so effectively. It turns out that soaking
beans and boiling them for at least 10 minutes, or cooking them on high
heat longer without soaking are both good ways to give our bellies a break.
What absolutely doesn't work is cooking them at low heat, like you would in a slow-cooker,
because it won't actually remove all the lectins. Slow cookers on the low setting generally only
reach around 190 degrees Fahrenheit, which is just not hot enough to get the job done. And
the difference in lectin content between raw kidney beans and properly cooked ones is huge.
Raw kidney beans contain between 20,000 and 70,000 units of lectin, while safely cooked kidney beans
contain between 200 and 400 lectin units. Boiling the beans eliminates the majority of the lectins,
and slow cookers just don't get hot enough to make raw beans safe for consumption.
Rather than using a slow cooker, you can certainly try a delicious stovetop recipe
for spicy pinto beans, but if you have a reason — and there are lots of good ones — for wanting
to prepare your meal in a slow cooker, you do have options that will make your meal safe to consume.
So how can you safely use beans in a slow cooker? If you have lots of other kitchen
tasks to accomplish or you want to throw ingredients in your slow cooker in order to
come home to a perfectly — and safely — cooked dinner, your meal can still contain beans,
as long as you handle them properly. One option is to use canned beans,
which have been cooked prior to canning. Another option is to cook the dried beans
before adding them to your recipe, so you're certain they're safe.
Slow cookers on the high setting typically get to about 300 degrees,
which might cause you to assume it's safe to cook raw beans in your slow cooker if you use the high
setting. Food Safety News, however, doesn't recommend this practice. Why? Studies of slow
cooker casseroles demonstrated that the internal temperature didn't typically exceed 167 degrees,
which doesn't achieve the 212 degrees the USDA recommends as safe for ensuring the lectins in
raw beans are neutralized. In order to ensure your beans are safe for use in your slow cooker,
it's best to either cook them ahead of time or buy canned.