Place the soya beans in a large deep pot after rinsing and fill in 3 times of the amount of water, about 6 cups. Soak for about 12-18 hours until soya beans Change the water 2-3 times during the soaking period and in summer keep them in the fridge. Soya beans should become larger after proper soaking. Drain the soy beans and rinse. Prepare 2 large deep pot, each filled with 5 cups of water. Start heating up over the low heat.
Divide the mixture evenly between the two prepared pots you previously. The mixture should not come up higher than halfway up of the pot. Adjust the heat to medium and bring the soya mixture to a boil. Turn the heat lower and continue cooking for about 10 minutes. Don’t leave your kitchen and watch the pot. Soya mixture can boils over easily any minute. Continue to cook this for about 15-20 minutes, stirring frequently. Finally the soya mixture looks kind of grainy as milk has separated from okara.
Line the plastic mold with holes, (bamboo, wood or stainless steel work too) with long cotton muslin. Place the vinegar in another large bowl and dilute with 2 tablespoons of water. Strain the soya liquid into another clean pot. Pour the strained soya liquid into the diluted vinegar. Shortly you would see the soya milk start curdling. Then pour those curds into the prepared molds. Fold the muslin over to cover. Weigh it down with a bowl or lid, so that some water can be pressed out. The heavier the weight, the longer the soya curds are pressed, the firmer tofu have you.