1 tsp. nigari or 2 tsp. calcium sulphate
1 cup water
• Simmer the soya milk for 5 to 10 minutes. Cool to about 180°F.
• Next prepare the coagulant – dissolve either 1 tsp. nigari (natural magnesium chloride) or 2 tsp. natural calcium sulphate in 1 cup of warm water. Less coagulant produces softer tofu, more produces harder tofu.
• Pour the prepared coagulant solution slowly into the soya milk while gently stirring. Stop stirring once 3/4 of the coagulant solution is added. Wait 2 to 3 minutes, then gently stir the forming curds and sprinkle the remaining coagulant solution into any milky areas. If there are no milky areas left, you do not need to add the rest of the coagulant solution. If there is still some milky area after adding all the coagulant solution, mix some more and add.
• Once all the soya milk is separating into small white curds of tofu and an amber liquid (whey), transfer the coagulated dispersion into a mould lined with cheesecloth. Any container that has many small holes in it to allow leftover whey to drain can serve as a tofu mould. Place a lid on the mould, pressing on the curds. A small weight of 3 to 5 lb. is placed on the lid of the container and allowed to sit for 20 minutes or so to expel water and aid in the firming process. A pot of water can serve as the weight. Empty the resulting block of tofu into a tub of cold water and allow it to sit for another hour. Tofu may be stored in the refrigerator. Change the soaking water daily.