Sort through and rinse the dried beans, discarding any that are discolored, moldy or disfigured.
Place the beans in a glass jar and add 3 cups of room-temperature water. The ratio of water to beans should be about 3:1. Allow the beans to soak for 8 to 12 hours. Cover the mouth of the jar with a cheesecloth and use a rubber band to secure it.
Drain the water after the soak, using the cheesecloth as a strainer, and rinse the beans with fresh water; drain and repeat 2 to 3 times. After the final drain, set the jar at a 45-degree angle, the mouth facing down, to allow any excess water to drain. The beans should remain moist, but not soaking in water. The jar can either be left at a 45-degree angle or placed on its side until the next rinse and drain.
Repeat the previous step 3 to 4 times each day until the beans have sprouted. The sprout will be white. For mung beans, let it grow to 2 to 3 inches. For larger beans, sprout only until the white stub appears.
Store sprouted beans in the refrigerator.