Source : foodnetwork
4 cups whole milk
2 cups heavy cream
1 teaspoon kosher salt
3 tablespoons good white wine vinegar
Set a large sieve over a deep bowl. Dampen 2 layers of cheesecloth with water and line the sieve with the cheesecloth.
Pour the milk and cream into a stainless-steel or enameled pot such as Le Creuset. Stir in the salt. Bring to a full boil over medium heat, stirring occasionally. Turn off the heat and stir in the vinegar. Allow the mixture to stand for 1 minute until it curdles. It will separate into thick parts (the curds) and milky parts (the whey).
Pour the mixture into the cheesecloth-lined sieve and allow it to drain into the bowl at room temperature for 20 to 25 minutes, occasionally discarding the liquid that collects in the bowl. The longer you let the mixture drain, the thicker the ricotta. (I tend to like mine on the thicker side, but some prefer it moister.) Transfer the ricotta to a bowl, discarding the cheesecloth and any remaining whey. Use immediately or cover with plastic wrap and refrigerate. The ricotta will keep refrigerated for 4 to 5 days.