Clean whole soybeans by removing dirt and damaged soybeans.
Soak cleaned dry whole soybeans in 5 times tap water weight overnight
or at least 8 hours at room temperature.
Drain and rinse with cold water (weight of the soaked soybeans is
about 800 grams).
Grind the soaked soybeans into slurry in a Waring blender in 3000
grams tap water for 3 minutes at high speed.
Filter through cheesecloth to remove fibrous materials (okara).
Collect the liquid portion.
Simmer the soymilk for 10 minutes. Weigh out 3000 grams cooked soymilk.
Cool the cooked soymilk to 80 degrees F. Monitor the temperature
of soymilk closely.
Add a preheated coagulant solution (15 grams calcium sulfate in
100 ml water) to the soymilk with agitation. Immediately stop stirring
and the flow of the soymilk as the curd beings to form. Allow the
curd to set without disturbing for 10 minutes. In general, the amount of coagulant is 0.25 to 0.5% of cooked soymilk
Break the curd evenly. Transfer coagulated dispersion into a tofu
mold lined with cheese cloth.
Fold cloth, cover with tofu lid and press for 15 minutes.
Remove tofu lid, unfold the cloth and remove the tofu mold. Cut
tofu into pieces and soak in cold water.
Hold the tofu in refrigerator and change soaking water daily.
Source: University of Illinois - International Soybean Program