In a medium size pot add the cream and place over medium heat, stir with a wooden spoon or rubber whisk, place a candy thermometer in the pot and heat until it reaches 185 F (85 C).
Remove from heat and continue to stir until the temperature comes down to 140 F (60 C).
Place the pot back on the heat and bring it back up to 185 F (85 C), continue to stir, then add the lemon juice lower the heat, keeping the temperature at 185 F and heat and stir for 3 minutes.
Remove again from the heat and bring the temperature down to 140 F (60 C), continue to stir.
Then pour the cream into a glass bowl, cover with a lid and cover with a tea towel, let sit at room temperature for 3 hours.
In a clean bowl place a sieve (make sure sieve is not touching the bottom of the bowl), and line the sieve with a clean cotton tea towel or 3 or 4 layers of cheese cloth, pour the cooled cream onto the cloth, then cover with plastic wrap and a clean towel.