1. Wash the wax gourd, keep the wax gourd skin and seeds, cut into small pieces, add brown sugar to wax gourd, mix well, and let stand for about 15 minutes until the wax gourd has a little water;
2. Put the mixed white gourd with brown sugar into the pot, add rock sugar and water, boil with high heat and turn to low heat for 1.5 hours, until the syrup thickens and wax gourd turns brown and transparent, then turn off the fire;
3. Filter the boiled soup with a sieve, press out the water from the wax gourd with a spoon, cool it, put it into a clean, oil-free sealed container, refrigerate it in the refrigerator, dilute it with warm water or ice water and mix it well before drinking.