Black beans have large round grains, light green in color, and are medicinal black beans. Small and long ones are common porridge to eat, and vinegar soaked black beans use large round grains. After cooking and air drying, soak it in vinegar, put it in a well-sealed container with a lid, and put it in a refrigerator without vinegar and black beans. Take 20-30 capsules a day. I'm not sure about the specific effect. You can try it (don't eat it if you have a bad stomach)