Step 1 Rinse a large saucepan with cold water (for easier cleanup). Pour the milk and cream into the saucepan. Add the salt. Bring to a simmer over medium heat; a skin may form on the surface. Continue to cook until you see bubbles all over the surface.
Step 2 While the milk is coming to a simmer, line a strainer with a double layer of dampened cheesecloth and set it in a bowl that is deep enough so the strainer is suspended above the bottom of the bowl.
Step 3When the milk has come to a simmer (it will take about 9 to 11 minutes), turn off the heat and pour in the vinegar. Leave it alone for about 1 minute, then stir slowly and gently. The milk will start separating into curds and whey (the liquid); you are looking for the whey to become clearish, which will take about 1 minute of gentle stirring.
Step 4Pour into the strainer. Lift the strainer out of the bowl and pour out the whey, then set the strainer back in the bowl and let the cheese drain for 15 minutes.
Step 5The ricotta is ready to serve now; it will be soft and moist. Gather up the corners of the cheesecloth and lift. Set the cheese in your palm and unfold the cloth. Invert a bowl or plate over the cheese in your hand, flip it over, and lift off the cheesecloth. You can also refrigerate it, covered, for later; it will be denser, more like cottage cheese.