Hi, Bill,

When cooking, beans foam up, the foam lifts the skins, which may block the pressure valve. So the first step is NEVER fill the cooker more than 1/3 full including both beans and water, and ALWAYS add 1-2 tablespoons of oil to the water to reduce foaming.

Most books say it is OK to pressure cook soybeans.

Here is what I do to make it safer:

Presoak the beans by boiling and then overnighting them in the fridge. Next day, rinse and keep working them through with your fingers, washing away as many of the skins as you can.

Use one of the modern safe pressure cookers with a safety valve (it releases the pressure if the tube blocks.)

Follow the guidelines above, 1/3 full, oil.

When you bring the heat up and the rocker begins to rock gently, turn the heat down to just hold the jiggle and DO NOT leave the kitchen until you are done cooking. Pay attention to the rocker. If the top stops jiggling and you have NOT turned the heat down, this is a sign it has blocked. Immediately remove it from the heat and cool in a sink of cold water (til the pot is cold when you hold your hand on the bottom), then open and cook normally. DO NOT try to repressurize a pot that has blocked once, it will do it again.

Using this careful method, I have not had soybeans block my pressure cooker, and they do seem to be more tender. However when I am making tofu I often use the open pot method, it makes better tofu.

In the pressure cooker, they only take an hour instead of 3. One thing, even well-cooked whole soybeans are not too easy to digest. It is more digestible if you crack them into bits with a food mill, blender, or food processor, after they cook. Or use soy grits instead of whole beans.

Let me know how it works for you.