this is everything you need to make ricotta cheese.
2 cups pasteurized (not UHT or ultra-pasteurized) whole milk
2 tbsp. distilled white vinegar
1/4 tsp. salt
this makes about 3/4 cup ricotta, so double, triple, etc...the amounts as needed.
it's important to use regular pasteurized milk as opposed to UHT or ultra-pasteurized (which is usually used for organic milk) because Ultra High Temperature milk has been briefly heated to 275° F and doesn't work well for making cheese (via thefoodlab). you can also use buttermilk or lemon juice in place of vinegar, and thefoodlab made a few different batches to compare.
add the milk and salt into a saucepan and heat on medium/high. stir continuously to prevent the milk from sticking to the pan and/or forming a skin.
right before the milk begins to boil, remove the pot from the burner and add the vinegar, then slowly stir for one minute. when stirring, do not separate the curds, which will almost immediately begin to form.
after the minute is up, place a towel over the saucepan for a few minutes to allow it to rest. pour the curds and whey into a colander lined with a few layers of cheesecloth, a thin dish towel, or damp (not sopping) paper towels to drain.
the amount of time you let the cheese drain is up to you thefoodlab suggests about 5 minutes for creamy curds, 15-20 for a spreadable, but not runny consistency, and and 2+ hours to overnight for dry, crumbly curds.
i let mine drain for about 5 minutes before i couldn't help myself and had to try a spoonful with a drizzle of honey. it was AMAZING.