Utensils:
1. A square box (a plastic tofu container with holes poked through the bottom will do). Line the container with a piece of gauze about four times the size of the box.
2. Wooden long-handled spoon.
3. Two-foot-square cotton cloth for straining the "milk" from the mash.
4. Blender
5. Large strainer
6. Large mixing bowl
7. Large cooking pot
Soak the soybeans in three times the amount of water overnight. The beans should triple in size. 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.
Add 8 ounces of this mixture to 4 litre boiling water. Reduce the heat to medium and cook for 15 minutes, stirring constantly. When it starts to boil up again, do not turn down the heat but add 2 or 3 drops of vegetable oil this will keep it from boiling over. Continue to cook another 7-10 minutes.
Place a wire mesh strainer lined with cotton cloth in another bowl and pour slowly through the lined strainer. This separates the soybean milk from the mash. Pick up the corners of the cloth and gather 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. Be careful to keep a tight hold on the ends of the cloth gathered in your hand as you twist and push with the spoon. If you drop a corner, very hot liquid can spill on you and the okara (soybean mash) will escape. (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). Place the tonyu in a large cooking pot and keep at about 60ºC over low heat. In a separate bowl, mix 5 times the amount of water as the tonyu with a two-finger pinch of nigari until dissolved. Slowly add half to the tonyu, stirring constantly.
After 5 minutes, add the other half of the nigari and water slowly and stir. Cover and reduce to lowest possible heat and let simmer for about 15 minutes as the mixture begins to coagulate. After coagulation, scoop the coagulated tofu out with your wooden spoon and evenly fill you lined container. Wrap the gauze over the top and let the container sit for 5 minutes to allow extra liquid to drain.
Immerse the container in a large mixing bowl filled with cold water, turn it over, gently pull off the container, and remove the gauze. Making tofu can be an interesting challange, but be careful not to burn yourself. The price of soybeans and nigari is negligible, but making tofu does take time and is painstaking. This process has been done by hand for centuries, beginning early each morning. Only someone who has made their own tofu knows how delicious the rewards can be.