To make this yoghurt, take a gallon of milk, bring it to the boil and then cool it a little in large jars. It needs to be finger hot. Mix a pinch of Lactobacteria Bulgaricus with a little warm milk and add it to the jars and stir it well. Cover the jars with blankets. Allow them to breathe but keep them well tucked in overnight and then move them to the fridge ready for use.