Instructions

• Ingredients – You would need milk (any type, 1 quart) and existing yogurt with active culture (2 tablespoons) from the supermarket. Existing yogurt is needed only for the first attempt.
• Utensils – Two pots (one big and one small so that the smaller can fit inside the bigger one), smaller pot should have a tight lid, a spoon to stir and a thermometer (with a clip).
• First step involves heating the milk to about 185 degree F. Heating the milk can be done in two ways – direct heating with continuous stirring or heating the milk using a water jacket. Water jacket is also known as double boiler. Water jacket helps prevent milk from scalding which can happen during direct heating if not careful.
• Make the water jacket – Place the big pot in the sink and then place the smaller one inside it. Hold the smaller one tightly and fill water in the big pot till it reaches half way up the side of the smaller pot.
• Add milk – If using water jacket method, put the larger pot with water over the heat source and put the smaller pot inside it. Since the smaller pot is empty it may float around, so hold it firmly with your hand and slowly add milk into the smaller pot. The water jacket will work only when the water level of the larger pot is equal to the milk level of the smaller pot. When this level is achieved you no longer would need to hold the smaller pot in position. For all other cases the smaller pot will float. So adjust the water level accordingly.
• Put the thermometer on the rim of the smaller pot using the clip. Water jacket or direct heating, make sure the milk reaches 185 degree F. At this temperature the milk usually starts to froth. In the water jacket, the water in the larger pot will be boiling for some time. Stir the milk whenever possible.
  Once the milk reaches the desired temperature, remove it and let it cool using cold water bath. Simply fill cold water in your sink or utensil (add ice if you can) and place the milk pot’s lower part into it to cool the milk. Cooling temperature required is 110 degree F. Stir occasionally.
• Now add the existing yogurt (which should be at room temperature) to the 110 degree F milk and stir. Cover the milk pot with a tight lid and keep it somewhere warm (on a heating pad, or inside oven with pilot light etc).
• Wait for atleast seven hours (wait more for better results). Once done remove the lid and stir thoroughly to mix the yogurt. Pour the yogurt in containers with tight lids and refrigerate one full night before using.