It is best to put rock sugar in mung bean soup. Rock sugar reduces fire, and its calories are lower than those of sugar, so it won't be easy to gain weight after eating it. When putting rock sugar, wait until the mung bean soup is cooked and turn off the heat before putting it in. Use the temperature in the soup to melt the rock sugar. In addition to controlling the time to put sugar, we can also make mung beans easier to boil through some tips.