Heat buttermilk over direct heat to 160°F. The buttermilk will automatically begin to separate into curds and whey. If it does not, slowly increase the temperature until it does, but do not go over 180°F.
Scoop the curds into a colander suspended over a clean bowl and lined with butter muslin. Make a draining sack and hang the curds to drain for 6-10 hours, or until the whey stops dripping and the desired consistency has been reached.
Pour the cheese from the draining sack into a clean bowl. Add salt and any extra flavoring ingredients.
This cheese will keep covered in the refrigerator for up to 2 weeks. Makes about 1 cup of cheese.