In a large pot over medium-heat, add the milk, cream, and salt. Stir with a wooden spoon to dissolve the salt and cook until the temperature reaches 185 degrees F.
Add the vinegar and stir for 15 seconds with the wooden spoon. Wait for 2 minutes and turn off the heat under the pot. Let rest for 15 to 20 minutes until the liquid thickens and the curds float to the top.
Using a slotted spoon or a strainer, scoop the curds into a large colander lined with cheesecloth and set over a bowl or into ricotta molds.
Refrigerate until firm, at least several hours or preferably overnight. Transfer the ricotta to covered containers. The ricotta will keep in the refrigerator for up to 12 days.
Ricotta molds are available from www.cheesemaking.com.