So, yeah, ideas (not just Bigfoot's) include adding baking soda, don't cook them with tomatoes (add tomatoes after the beans are soft), pre-soaking overnight, and other stuff. They say older beans stay firmer longer.
FYI, Bigfoot said to use ¼ teaspoon of baking soda per cup of beans, and that the beans should soften a lot before 90 minutes of slow simmering.
So, I'm experimenting with cooking two cups of beans in a slow cooker on high with ½ teaspoon of baking soda. They look like red-ish pinto beans. Pinto beans are notorious in my mind for taking a long time to soften, and notable for tasting really good when they are really soft. I'm using about two inches of water above the beans. We'll see what they're like in a few hours (it's a slow cooker, so I'm planning for more than 90 minutes: 3 to 4 hours). I used cold filtered water, and didn't add anything else but beans and baking soda. I did not soak the beans prior to cooking.
If it tastes bad afterward, I intend to add citric acid or ascorbic acid and/or brown sugar to remedy the situation; hopefully that works. That is not what Bigfoot suggested. That's my idea.
Baking soda is sodium bicarbonate; citric acid and ascorbic acid should reduce it to such as sodium citrate or sodium ascorbate (although I understand the beans might complicate matters). I believe it's the bicarbonate that has the bitter taste. Brown sugar is acidic and in my experience, it makes baked goods with baking soda in them taste and smell better.
I plan to add epazote and seasonings after it's soft; maybe tomatoes and peppers, too.
Location: SW Idaho, USA
USDA hardiness zone: 6
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