I've only ever made this with UHT milk but I would guess it would work just fine with normal, store-bought cow milk too.
3 liters whole milk
1 liter cream (whipping cream)
Salt to taste - about 1 tsp.
1/3 c. apple cider vinegar
1/2 tsp. citric acid (OR 1 Tbsp. lemon juice)
Mix vinegar and citric acid together. (I use a glass measuring cup.) Set aside for later use.
In a stainless steel pan, bring milk and cream to just shy of a boil (around 190 degrees Fahrenheit), stirring constantly. (This prevents the milk from scalding and helps it all heat to the same temperature.) The milk and cream should just start to foam around the edges.
Turn off heat and add vinegar mixture, stirring slightly. Let rest until cooled. The milk proteins and the whey will start to separate.
Once cooled, put a colander over a bowl (or pan). (You will want the colander to sit high enough over the bowl to give the whey enough room to run off.) Inside the bowl, place a butter muslim cloth. (I use a flour sack towel which works but requires more time to drain.) Pour ricotta mixture through the cloth-covered colander and allow the mixture to drain.
Once it has drained to your desired texture (about an hour for me), place in an airtight container. At this point, stir in the salt to taste. Mix well and then store in the refrigerator.
Reserve whey for making bread. It is also useful in "feeding" plants.
Super yummy and great on toast, as a spread for sandwiches, in lasagna, and so many other yummy places!