1. After the water is boiled, be careful not to eat the water chestnut skin together, because the water chestnut skin is too hard to digest in time. In order to avoid injury to digestive tract and indigestion, water chestnut skin should be spit out.

2. Wash the bought water chestnut, and the surface is thin. Wash the buds and roots.

3. Then soak in light salt water for half an hour to sterilize the surface of water chestnut.

4. Cut the fattest circle in the middle of the water chestnut and divide it into two parts: the bud surface and the root surface.

5. Clean the skin on the root surface with a knife, pay attention to the concave part on the bottom surface, and remove all dirt and skin.

6. Pour 1500ml of clean water into the pot, about 3 mineral water bottles, and add 7 or 8 water chestnuts.

7. Bring the fire to a boil, turn it to a low fire for 20 minutes, or add some rock sugar according to your own taste.