What you need:
Organic Live Yogurt
Sterilized Jars with lids
Pot - big enough for approximately 2 liters of milk.
Large Stock Pot
Pour milk into large pot and continue to stir the milk until it makes a frothy foamy top. carefully pour the warm milk into the sterilized jars. And let it cool down a little bit. When it is tepid - that is when it's still warm but not hot. Scoop 2/3 tablespoons of yogurt into each jar. Giving it a quick stir. But be careful not to over mix.
Close the jars with the lids and place into the large stock pot. Fill the stock pot up with the hottest water from your tap. Up unto the level of the yogurt in your jars.
Cover pot with lid and place in a safe place to cool down overnight. In the morning you can remove the jars from the pot. Dry them and put them straight into the fridge. The yogurt will thicken as it cools down.