Soy Yogurt

The soy yogurt is not identical to dairy yogurt but it works well in cooking. As a starter you can use dairy yogurt. Bring the soymilk to 42-45°C. The culture will only thrive in a narrow temperature range, too cool and it won't be active, too hot and it will die. It is just below body temperature so it should be the same temperature as baby's milk. Add 2 - 4 tablespoons of starter to the soymilk and mix well with a sterile spoon. Do not stir or move the container till the yogurt sets in - about 5 - 6 hours. Chill.
Making the soy yogurt thicker
You will notice that home made yogurt will be a little runnier than dairy yogurt. To improve the thickness of the soy yogurt you can add one level teaspoon of agar powder, which is premixed in 50 ml water, to the soymilk when it starts boiling. You can also use corn starch or arrowroot as a thickener. Disperse 2 teaspoon of starch in 30 ml cold water and add this mixture to the soymilk just before boiling.