2 or 3 cups soybeans
1/4 teaspoon Nigari or calcium sulfate per cup of soy beans
8 cups water per cup of soy beans
(1 cup soy beans is 178 grams or 6.3 oz)
Each teaspoon of coagulant (Nigari or calcium sulfate) will be dissolved in 1/4 cup of boiling water
a. Soak the soybeans in three times the amount of water overnight. The beans should triple in size.
b. When soft, drain off the water through a strainer, and pulverize in a blender on high speed for 3 to 4 minutes, until beans are completely pulverized. Large amounts of beans may require processing in multiple batches.
c. Each cup of soy beans requires 8 cups of water. Put water into the largest pot you can find and heat to boiling. This process is foamy and prone to boiling over. Add pulverized beans to boiling water.
d. Reduce the heat to medium and cook for 15 minutes, stirring constantly. The temperature should stay between 180F and 212F. Spritz with cold water if it shows signs of foaming over.
e. Place colander into large pot big enough to hold the soy/water mixture. Place nylon straining bag over both of them. Pour mixture through straining bag.
f. This separates the soybean milk from the mash. Pick up the bag and twist tight. The mixture is still hot, so using the long-handled spoon, force the remaining liquid into the bowl by pressing repeatedly on the twisted cloth. (The leftover mash is called okara. The soybean milk is called tonyu and can be refrigerated and drunk for a few days if you wish). Save okara for making okara burgers.
g. Place the tonyu in a large cooking pot and keep at about 180 F over low heat. Dissolve coagulant (nigari or calcium sulfate) in boiling water. Slowly add 1/2 to the tonyu, stirring constantly.
h. After 5 minutes, add the other half of the coagulant and water slowly and stir. Cover hold at 180F for about 15 minutes as the mixture begins to coagulate.
i. After coagulation, scoop the coagulated tofu out with your wooden spoon back into nylon bag. Twist bag gently to quickly drain excess liquid. Place bag into mold and apply pressure for at least 20 minutes.
j. Remove bag from mold and play in a large mixing bowl filled with cold water and gently separate tofu from bag.