Line a colander with three layers of cheesecloth and set it over a bowl.
In a large pot over medium-high heat, mix together milk, cream and salt. Bring to a simmer and heat until the mixture just begins to curdle, approximately 12-15 minutes, temperature should reach 195 degrees. Stir frequently to prevent scorching. Add lemon juice and continue to boil, stirring constantly until curds separate, about 2-3 minutes.
Pour mixture into lined colander and drain 1-2 hours. Transfer to an airtight container and store up to one week. For an even creamier texture, whip in food processor.