Add your milk to a saucepan and heat, stirring occasionally until it reaches 82 degrees Celcius, hold at this temperature for 5-10 minutes stirring constantly.
Turn off heat and allow milk to cool to 43-45 degrees Celsius.
While milk is cooling, wash jars and lids in very hot soapy water, rinse and air dry.
Add natural yoghurt to the milk and stir well until fully combined.
Pour milk into clean jars and place lids on.
Ferment at 43-45 degrees Celcius for 10-12 hours.
Transfer to the fridge to store.
Yoghurt will store in the fridge for 2 weeks, after this time check yoghurt for taste, smell, appearance that indicate it being off. Once jars opened, use within 1 week.