In a large pot (preferably one with a thick bottom) add the whole milk, buttermilk, and a tiny pinch of salt. Turn the heat on high. Occasionally stirring the milks, be sure to also scrape the bottom of the pot. If you are using a thinner-bottomed pan, I’d suggest using a medium-high heat.
Once the curds begin appearing, they don’t stop. Be sure to keep stirring, but once the heat is quite hot, and much of the ricotta mass has floated to the top, you may turn off the heat. Some suggest that the heat should be turned off once the mixture has reached 185ºF (101 Cookbooks suggest 175ºF), but the best way to know is if the top is all curd and the liquid underneath is transparent and watery.
Fold 2 yards of cheesecloth as many times as possible over a colander. Slowly and carefully pour the ricotta mixture into the cheesecloth. Allow one hour to drain.
Before placing in an airtight container, squeeze the ricotta inside the cheesecloth to remove any excess water. If you have a mold for the ricotta, you will want to do another round or two of squeezing to ensure stiffness. Eat within several days.