The first point: Frozen mung beans, when cooking mung bean soup, be sure to freeze mung beans for more than 6 hours in advance, because the temperature of frozen mung beans is lower than 0 degrees Celsius, and when low-temperature mung beans are put into boiling water, they will quickly absorb the heat in the water, thus expanding rapidly. The principle of cooking mung bean soup by freezing method is the well-known physical principle of heat expansion and cold contraction.

The second point: stew for more than 10 minutes after boiling for 10 minutes, and stew for 10 minutes after mung bean is boiled for 10 minutes, so that the fragrance and nutrition in mung bean can be combined with water, thus making mung bean soup more fragrant and refreshing.