How to Cook Adzuki Beans. The beans must be cooked prior to consumption. Soak 1/2 cup of beans overnight in ample water. Drain and simmer in 2 cups of water for 40 minutes to an hour. Alternatively, pressure cook the soaked beans in 2 cups of water for 5-9 minutes at high pressure. If you don't have time to soak the beans, pressure cook for 15-20 minutes.