4 c fresh heavy cream
1/4 tsp tartaric acid
I have read that tartaric acid is available in pharmacies. Place cream in a glass bowl, and place bowl over a larger saucepan. You are making a double boiler. Add cold water to the larger pan. Place the pan over medium heat and bring the cream to a temperature of 180 degrees, stirring every so often with a wooden spoon. Use a candy thermometer.
As soon as the cream reaches 180 degrees, remove from heat, add tartaric acid, and stir with a wooden spoon for 30 seconds. Remove glass casserole or bowl from the larger pan, and stir another 2 minutes.
Line a fine-mesh strainer with thick cheesecloth, and place strainer over a bowl. Pour the cream into the strainer. Allow to stand and drain for 12 hours in a cool place or on the bottom shelf of the refrigerator.
Prepare four 9-inch squares of cheesecloth. Divide mascarpone into quarters. Place each quarter of mascarpone on each square of cheesecloth and fold like a package, without tying it. Place packages on a plate and refrigerate for another 12 hours before using. Use within 48 hours. Makes 4 c of sweet mascarpone. For a tangier mascarpone, increase tartaric acid to 1/2 tsp.
8 oz cream cheese, soft
3 T sour cream
2 T heavy cream (35% whipping cream)
Beat together. Makes 1 c of cheese which has a nearly identical texture and taste to mascarpone.