Soak in cold water for two hours before cooking. After boiling, cook for another 5 minutes over medium heat.

When cooking black bean porridge or other bean porridge, because beans are more difficult to rot than rice, when cooking porridge, put a little water first, put beans into the pot, add a little cold water after boiling (we call it tumbling), repeat this for two or three times, then add water to the required amount, add rice after boiling, and the rest remains unchanged. Try it, bean porridge is sticky and rotten, not only fast, but also hot.