There is a surprising amount of lore associated with cooking dried beans - or perhaps it's not so surprising. Beans are, after all, a great source of protein, carbs and other nutrients and, once dried, have a long shelf life. They're also relatively easy to grow and because of their ability to bind nitrogen to the soil they leave the ground they're grown in in better shape for other crops. So they've been a cherished food source for thousands of years.
A Flatulent Falsehood
Beans can indeed cause flatulence - gas. Beans contain some carbohydrates called oliosaccharides that our stomachs can't digest so they pass on through to our gut where bacteria exist that can digest them - and may produce gas in the process. However, the amount of gas produced depends on your intestinal health, the particular bacteria in your intestine and the beans and their preparation. For instance, most beans seem to have little effect on me.
The idea behind soaking beans in water that is then discarded is based on the belief this will eliminate the gas-causing oliosaccharides. This is true, to some degree, but research shows it only reduces them by around 25 percent and in addition, the cements that hold a bean's cell walls together also produce gas and aren't reduced by soaking. So soaking beans to eliminate gas is only slightly effective. And you lose water-soluble nutrients as well.
You do have to rehydrate dried beans and this is accomplished equally well by overnight soaking (12 - 24 hours) in cold water or simmering in hot water (3 - 4 hours). If you wish you can discard the liquid at that point and reduce the gas possibility by a small amount while also discarding some nutrients or you can continue and cook the beans in the same liquid. I recommend keeping the nutrients and taking Beano if gas is a problem. Beano contains an enzyme that breaks down the offending carbohydrates.
When I learned these facts I had an epiphany: as long as the beans are soaking up liquid while they rehydrate, why not have them soak up flavor too? So I made a pot of ham stock and rehydrated some beans in the stock - then went on to finish cooking them in the stock. Wow! They were the best beans I'd ever eaten.
Tough versus Tender
A genuine falsehood is that salt makes beans tough. It doesn't. Acid makes beans tough - and so does age. In general if you cook up a batch of tough beans the odds are they're old and/or have been exposed to air. You may have just purchased them at the supermarket, but that doesn't mean they were picked within the past year. They could easily be 10 years old because dried beans can keep a long time with no effect beyond getting harder and harder.
I always add salt to the water when I cook pasta, potatoes and rice in because the salt seeps into the beans adding seasoning but also taking flavor along with it. So I always salt the stock I use when cooking beans. The salt will not make the beans tough.
However, acid in the form of vinegar or lemon juice or something similar will make beans tough. The acid binds with the beans' seed coat and makes it more impervious to water as well as making the coat harder. So if you’re adding much acid (of whatever sort) to beans wait until the end.
Small amounts of acid, though, don't have much effect. I often add tomatoes when I begin cooking beans and the acid in the tomatoes has no noticeable results. If you suspect the beans will be tough add half a teaspoon of baking soda to the cooking liquid.
- Here's how I usually prepare dried beans:
- Dump beans in a Dutch oven and add twice as much well-flavored and -seasoned stock to pot.
- Place on the stove and bring to a boil. Immediately reduce heat to a gentle simmer.
- Cook for 3 hours and top-up stock as needed to keep beans covered to 1/2-inch depth.
- Add other ingredients based on your recipe.
- Whether I'm making a soup or a casserole-type dish, I prefer the final cooking take place in a Dutch oven in the oven at 300 degrees. The beans and other ingredients will simmer surrounded by heat instead of cooking from the bottom up as they do on the stove-top.
The final cooking will take another 3 hours. And check occasionally to make sure the beans aren't drying out.