The practice of mung bean rock sugar soup: 1. Wash mung beans, soak them in clear water for half an hour, then take them out and put them in the pot; 2. Add two or three centimeters more water than mung beans and boil; 3. Then rinse it twice, then fill it with water and add a large piece of rock sugar. After the fire is boiled, simmer for about 20 minutes until the mung beans are rotten. Rock sugar: This is ice crystal made of white sugar. It is a large crystalline sugar made of sucrose and protein through redissolution, cleaning and recrystallization. There are single crystal and polycrystalline, transparent or translucent. Because its crystal is like ice, it is named rock sugar, also known as "ice particles". Natural rock candy has white, yellow, light gray and other colors. In addition, there are all kinds of colored rock candy with edible pigments on the market (mainly for export).