8 cups whole milk
1 cup heavy cream
1 tablespoon kosher salt
¼ cup freshly squeezed lemon juice
1. Place a colander inside a larger bowl, line the colander with cheesecloth, and set aside. Slowly bring the milk, cream, and salt to simmer in a heavy 6-quart pot over medium-low heat, stirring occasionally, about 15 minutes. When the milk barely begins to simmer (about 180°F to 200°F), add the lemon juice. Stir constantly until the mixture starts to curdle, about 4 more minutes.
2. Remove the pot from the heat. It is very important that you do not simmer the milk after the curds begin to separate or the curds will become dense and dry. Allow the curds to rest for 10 minutes.
3. Pour the milk mixture into the lined colander to strain. The milk will have already formed hard curds—ricotta cheese. It is ready to be used after 5 minutes because not much more moisture will be extracted by further draining. Reserve the liquid for another use (at the restaurant they use this liquid, whey, for braising meats; it can also be used in place of chicken stock when a small amount of stock is called for in a recipe).