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Dec 4, 2007 08:24 PM

Kidney Beans and Pressure Cooking

I just read that even after extended soaking time, raw kidney beans should be boiled for 10 to 15 minutes to release potential toxins, which I believe are called hemagglutinins. Then, they can be cooked. I'm not sure if this procedure is used for slower cooking times as in a stock pot of boiling/simmering water or in a crock pot.

If a pressure cooker was used, is it reasonable to assume that because of the higher cooking temperature, that these "toxins" will be eliminated, and thus, no need for the additional boiling just after soaking?

From what I read, only kidney beans in the bean family have this toxin, and thus other beans don't necessarily need this after soaking boiling prep cleaining process.

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  1. I've read about some beans needing to be brought to a full boil, but that seemed to be part of the regular cooking time, not a separate step. I think it is more of an issue if you try to cooking them in a slow-cooker where they might not come to a full boil at any time,rather than to regular stove top cooking. Sass 'Cooking under pressure' does not give any special instructions for kidney beans.
    Slow cooker temperatures may actually increase the toxin. But 10 minutes of boiling (without further change in water) drops it to safe levels. PC temperatures are even higher, so they should be as effective (may be even more so) as regular cooking. The toxin is present in many beans, but most concentrated in red kidney beans.

    I can't find this in so many words, but it appears that the cooking actually changes the toxin, as opposed to leaching it out of the beans. Hence the cooking water does not need to be discarded.

    1 Reply
    1. re: paulj

      Beans, Beans The Toxic Legume.
      If undercooked,
      Watch what you consume.