When washing (scalding) most vegetables, adding a little alkaline noodles will make them look greener, such as celery and garlic shoots. And of course, soybeans. But edamame doesn't have to be cooked for a long time to stay green. After a long time, it will become "yellow" and ugly. Usually when you cook edamame, you only pay attention to "taste one later" (I don't remember the time, ha). It doesn't smell like beans. Just fish it out in time.