There are rumors that dried red kidney beans must be boiled—not just simmered—to make them safe to eat. Is this true? And if so, how long should they be boiled?
Many dried beans contain proteins called lectins that, if ingested raw or partially cooked, can produce symptoms similar to those of food poisoning. Red kidney beans are higher in lectins than other beans, but there’s no need to fret: A 1985 research paper published in the Journal of Food Science reported that lectins are completely destroyed when beans are boiled for 10 minutes. To keep them from turning mushy, we suggest boiling the beans at the beginning of cooking (when they are at their sturdiest). After that, you can turn down the heat and simmer them until tender.