Homemade Natural Yoghurt

Incubation: The milk mixture has to remain at 40 degrees C.  There are a number of ways to do this.  Put the jars into an esky of 40 degree water, adding more water as needed.  I use a sous vide machine and set it to 40 degrees.  If you don’t have either of these put the pot of water in the sink with the lid on and fill it with warm water and also surround it with 40 degree water.  This method will take a bit more work as the water surrounding will cool off quicker.  Check every couple of hours and add hot water to bring back up to 40 degrees.