1/3 cup yogurt
1 quart milk
Wide mouth thermos
Candy thermometer ( the right temperature is essential)
Heat milk to 200 degrees f to sterilize it. Bacteria will interfere with the yeast. In the meantime fill the thermos with boiling water to sterilize it and preheat it.
Let the milk cool to 110 -115 degrees f. Stir in yeast. Mix well. Heat gently if needed to have an end temperature between 110 and 120 degrees f.
Empty hot water from thermos. Pour in yeast milk mixture. Let sit for 8 – 12 hours.