Why I added baking soda when I cooked dried beans

In my guide to making your own tempeh, I include a warning on not adding any baking soda to the water when cooking dried beans: Rhizopus oligosporus, the fungus that turns beans (and grain) into tempeh, requires an acid environment and will not grow if the beans are alkaline.

Someone in the Tempeh Makers group on Facebook asked why would I even add baking soda when I cook dried beans. Here’s why: if you’re just cooking beans to eat, a little baking soda makes them cook much faster, be more tender, and (some say) less gassy. See this Cook’s Illustrated article. It worked so well when I tried it, I made it a habit. All well and good, until I tried to make tempeh with beans cooked that way: consistent failure until I twigged to the problem.