Mix milk, heavy cream (or just 2% milk) and salt in a saucepan. Bring it to the stove, at medium high heat, stirring occasionally. Don’t let the milk boil. Keep watching it closely. As soon as you see the first bubble rising, turn the heat off. Immediately add the vinegar and stir. The milk will curdle. Cover it with a clean towel and let it rest for about 10 minutes (30 minutes if you’re using 2% milk). Meanwhile, line a mesh strainer with two layers of cheesecloth and put it over a large bowl to catch the liquid. Pour milk through the strainer and let it drain for about 1 hour if you've used whole milk and heavy cream and longer if you've used 2% milk, I usually put the strainer and the bowl that is catching the liquid in the fridge for a few hours. The longer you drain, the firmer your ricotta is going to be. It’s magical what happens. You’ll see. You will never be sorry you made this!