I am from Guangxi. What I know is that it is made from the seeds of a plant whose fruit looks like soaked fruits. It is sold in grocery stores. After buying it, wrap it in white cloth and tie it tightly to make it leak-free. Put a certain amount of water in a container, soak the seeds in the water and rub it. Slippery, rub it until the water becomes sticky, and then add an appropriate amount of clear lime water into it. After stirring it, don't touch it again. Soon it will automatically form a jelly-like shape. This is what I saw in my family when I was a child. Made.

Nowadays, white jelly and black jelly are sold in general stores in Guangxi. They are powders. You can make them quickly according to the instructions after buying them, without the hassle of manual work