Rinse the inside of a large non-reactive pot with cold water (this helps prevent the milk from scorching).  Add the milk and cream to the pot and place on medium heat.  Add salt and stir briefly.

Allow milk to heat up slowly, stirring occasionally.  After a few minutes, you will notice steam starting to form above the surface and tiny bubbles appearing on the milk.  You want it to reach 180-185°F, which is near scalding temperature, just before it comes to a boil.  Check the temperature with your instant read thermometer.  When it reaches the correct temperature, take the pot off the burner.

Add the vinegar and stir gently for only one minute.  You will notice curds forming immediately.

Cover with a dry clean dishtowel and allow the mixture to sit undisturbed for a couple of hours. (This is when you get to go do your shopping or grab a coffee with a friend!)

When the ricotta has rested for about 2 hours, take a piece of cheesecloth, dampen it and place it inside a colander.  With a slotted spoon, ladle out the curds into the prepared colander. Place the colander with ricotta curds inside a larger pan so it can drain freely.

If there is still a great deal of milk in the pot, return it to the fire and heat again to 185°F.  Take it off the heat.  Stir in an additional 2 tablespoons of vinegar and allow to sit again for another two hours.

Ladle out the additional curds into the other that is draining.  Let it drain for about two hours or even overnight, depending on how creamy or dry you want your cheese to be.

When it has drained to the desired consistency, remove it from the cheesecloth and store it in a tight sealed container.

Refrigerate until ready to use.  It will keep for up to 7 days.  Unfortunately, ricotta does not freeze well.

Other serving suggestions:  Ricotta can be served as an appetizer on crostini or cracker, or used in a sauce in place of cream.