Mix milk and salt in a pot. Cook over medium high heat, stirring every few minutes, until the milk reaches 185 degrees. (If you don’t have a candy thermometer, bring the milk to a simmer but do not let it boil.)
1/2 gallon whole milk, 1 teaspoon sea salt
Stir in the lemon juice or apple cider vinegar, turn the heat down to medium, and let sit for one minute. As soon as you stir in the lemon juice, you may see the milk start to curdle and separate into curds and whey.
2 tablespoons lemon juice
Gently stir again and turn off the heat. Let sit without stirring (it’s hard not to keep checking it!) for ten minutes.
While the pot sits, line a colander with several layers of cheesecloth. Place the colander in a bowl to catch the whey.
Pour the contents of the pot into the colander. Pull opposite corners of the cheesecloth together and tie a knot. Repeat with the other corners, then hang this little bag-o-cheese on the handle of a wooden spoon suspended over the dirty pot to catch any drips. Allow to drain for a couple of hours, then transfer your homemade ricotta cheese to a glass container and refrigerate.
Notes
I used raw milk but whole pasteurized milk will be fine. Just try to find milk that hasn't been *ultra-pasteurized.
Alternatively, you can use a jelly bag to drain the cheese.