In the hot time of the year, Lü Dou Tang is a sweet and light soup made with green mung beans that is popular all over China. It helps you to cool down from summer heat, and has a high nutritional value.
Mung beans were first noted in one of the Ming dynasty classics of the TCM Materia Medica, Ben Cao Gang Mu 本草纲目, by the famous doctor, Li Shizhen 李时珍. Mung beans are cooling, relieve heat stroke and thirst, clear toxins and internal heat, promote urination and relieve edema, calm the Shen 神 (spirit and mind), reinforce Original Yuan Qi 元氣, harmonize the organs and nourish the skin.
100g mung beans, washed
1 liter water
1 teaspoon rock sugar (or white granulated sugar)
Bring 1 liter water to boil. Add washed mung beans and sugar, turn off heat, cover and let the beans soak in the hot water for 20 minutes.
Turn the heat on and bring to boil once more, turn off heat and leave the soup to cool.
You can, of course, eat the soup warm. Normally it is left to cool to room temperature.
Keep the remaining soup in the refrigerator for up to three days, and eat it cool or at room temperature. For those who prefer it warm, simply reheat it for a few minutes over a low heat.