Fill the water bath with clean, cold water and set the temperature to 78°C
Pour the milk into a large, food-grade zip lock bag and stir in the salt
Carefully lower the bag into the water bath, without allowing any water to get in to the bag or allowing any milk to leak out. You will see the air is expelled from the bag, caused by the surrounding pressure of the water - this is known as the Archimedes principle. Once all of the air has been expelled, seal the bag
Leave the milk in the water bath for 30 minutes, before opening the bag and stirring in the vinegar
Reseal the bag, again using the Archimedes principle, and leave to cook for a further 15 minutes
Line a sieve with a few layers of muslin and set it over a bowl
Use a slotted spoon to collect the curds that have formed in the bag and transfer them to the sieve
Leave the cheese to drain for 1 hour, then tie up the muslin and squeeze out the remaining liquid. Leave for a further half an hour to one hour to finish draining
Transfer to a bowl and serve
