150g Dried Soy Beans :
2g Calcium Sulfate (aka Gypsum, used for wine/beer making) water
Soak beans in water overnight.
Place the beans in a blender, adding water until they're covered (about 1" above the bean level). Blend for two minutes until it's a smooth liquid.
Using a sack made from two pieces of cotton cloth, squeeze out the soy juice.
Bring the juice to a boil in a saucepan over medium heat, stirring occasionally to avoid burning. Reduce flame to low and simmer for two to four minutes or so.
While the mixture continues to boil, prepare a small dish and dissolve Calcium Sulfate into two to three tablespoons of water.
Using a food thermometer, bring the temperature of the boiling mixture to 176?F.
Pour all of the mixture into a dish with the Calcium Sulfate while mixing briskly for three seconds and stop. Wait 10 minutes for the tofu to set. Serve hot right away, chill or squeeze more water with a cotton cloth while it's still hot for harder tofu.