Cooking beans with intact skins

Question

When my grandmother would cook dry beans, she always soaked them overnight, and they came out "perfect" in the sense I liked, which was that the beans were soft, and in particular, the skins were unbroken in the process. The beans remained whole until eaten. I've tried to reproduce this but have not achieved it. Whether soaked overnight or not, the bean skins would always crack open during the cooking.

Researching this, I read a lot of concerns about whether the skins are hard or soft, and solutions to deal with that issue. But none of them ever associated whether hard or soft skins would prevent breaking or cracking. This has also uncovered some suggestions like quick pre-cooking, soaking cold, soaking luke warm, adding salt, etc. Yet nothing has mentioned which of these methods avoids breaking up the bean skins.

Anyone know how I can avoid the skins breaking up? I'm guess I need to make sure they can expand as much as the bulk of the bean does. I'd like to apply this to a wide range of bean types (kidney, pinto, white northern, black beans, and even unsplit lentils). What should I do to get the unbroken bean (without getting an undercooked bean, or sloppy mush)?

Answer 1

According to this extensive bean cooking guide from University of Alaska Fairbanks, the secret is to simmer the beans gently. Unfortunately, they have little more to say on the matter.

Kenji Lopez-Alt, in his column on Food Myths at Serious Eats says (emphasis added):

Most of us have been told at some point in our culinary careers that salting beans will cause them to toughen. It's incredible that this little bit of culinary mis-wisdom still lingers, for it couldn't be further from the truth. A simple side-by-side test can prove to you conclusively that salting beans (both the water used to soak them in and the water used to cook them) actually tenderizes the skins.

It's got to do with magnesium and calcium, two ions found in the bean skins that help keep the structure of the beans' skin intact. When you soak the beans in salt water, sodium ions end up replacing some of the magnesium and calcium, effectively softening the skins. Your beans come out creamier, better seasoned, and have a much smaller likelihood of exploding while cooking.

He provides this image of the contrast:

I believe the take away from this is:

1. Pre-soak your beans overnight, as your grandmother did using salted water
2. Cook them at bare simmer, stirring them minimally, to prevent physical damage to the skins.

The second can easily be achieved by placing the bean pot in a moderate (350 F, 180 C) oven rather than doing it stove top.

Answer 2

I just finished a Pinto bean recipe found in Cooks Illustrated Jan Feb 2015 edition titled Drunken Beans. They suggested:

• 3 Tbsp of salt for ever 4 quarts of water used during a soak.
• Duration 8 - 24 hours, drain and rinse.
• Dispose of soaking water and use a moderate oven 350 degrees to cook the beans. Oven use allows the bean to cook gently.

Duration for this recipe was ~1 hour but have the new liquid brought to a boil on the stove top before inserting into the preheated oven. Do not add any tomato based product until the beans have cooked for the required time. They state that adding tomato product toughens the skin if added at the start of cooking and a salt soak softens the skin.

I have to admit that the beans came out perfect without any splitting.