Remove all trays from your oven and preheat to 40° Celsius
Place the milk into a sauce pan and over a low temperature heat to 40° Celsius
Remove from the heat and stir in the yoghurt and vanilla
Transfer to oven proof jars and cover with cling film
Place the jars into the oven and leave to cook for 11 hours
Remove from the oven and place into the fridge to cool
Once cool, remove the cling film and put the lids on the jars
Remember to set aside 150g to use for your next batch
Notes
* for this recipe please make use of UHT milk. If you don't then heat your milk to 90° Celsius and then leave to cool until it is 40° Celsius ** Lactobacillus bulgaricus and Streptococcus thermophilus