1. Wash the mahogany foam. (It's better to have fresh mahogany.)
2. Cut the sugar cane with a knife and scrub it clean.
3. Chop into small sections, and then chop into small strips.
4. Wash the kumquat and cut it in half. (The seeds are said to have the effect of relieving cough and reducing phlegm, so I did not remove them.)
5. Put all the ingredients into the soup pot, pour an appropriate amount of water, and bring it to a boil.
6. Turn to low heat and cook for 30-40 minutes, turn off the heat and let it sit for 30 minutes.
7. It's ready to drink.
8. Sweet and sour, appetizing.
