8 cups unsweetened soy milk (use store bought, make your own - recipe below.)
2 tsp food grade calcium sulphate powder 石膏粉 available from Asian stores
2 tsp cornstarch
1/4 cup cold water
Mix calcium powder and cornstarch with water. Place in large pot or bowl with cover.
Bring soy milk to boil in uncovered pot, watching carefully so it doesn't boil over.
Pour over carbonate mixture and cover and let stand for 30 min to set.
Serve with syrup made by boiling rock sugar with some wataer. If desired, a slice of ginger can be added.
Soy Milk:
Soak soy beans overnight.
Put some in blender with water to cover and blend till fine. Repeat till beans are used up.
Pour some mixture into cotton cloth and wring to obtain soy milk. Discard the fiber.
Put soy milk in pot and stir and bring to boil over medium heat. Do not walk away, watching carefully so it doesn't boil over.
Simmer for five minutes. Add sugar to soy milk if desired or make tofu flower with it.