Li Xiang used cooked gypsum to set the tofu. Following Granny Li Xiang and Third Granny's instructions, he broke off a small piece of the gypsum, ground it into a powder, and mixed it with clear water to create a slurry.
In the countryside, there was no such thing as precise measurement; everything was done by experience. Li Xiang estimated the ratio of gypsum to soy milk to be somewhere between 1:300 and 1:500.
He sprinkled the prepared gypsum slurry evenly into the large basin, gave it another gentle stir with a long-handled stainless steel ladle, then covered it. A short while later, he lifted the lid to find that the soy milk had "transformed" into smooth, white, and tender tofu pudding.
This was southern-style tofu, which was whiter and more delicate than northern-style tofu. The sweet tofu pudding preferred by "Team Sweet" was usually made from this southern style, as sweet tofu pudding demanded a higher quality of "delicacy" compared to its savory counterpart.
