In a pot over medium-low heat, combine milk, cream and salt. Heat slowly to raise the temperature of the mixture to 202F. Be sure to keep an eye on the contents and whisk intermittently to ensure milk does not scald at the bottom of the pot. Once the mixture has reached 202F, remove from heat and whisk in lemon juice. Mixture should curdle. Let rest for 15 minutes.
Line a colander with a double layer of cheesecloth and place into a large bowl. Pour the ricotta mixture into the colander and let drain for 10 minutes, pouring drained liquid from bowl to keep the curds out of the liquid. Tie up the ends of the cheesecloth and then hang the bundle over the sink or a bowl and let drain 30 minutes.