Historically, the Italian Mascarpone was a triple-creme cheese made from crème fraîche. In the same tradition, our recipe will use heavy cream. Traditionally, Mascarpone are not pressed after the lactic fermentation, rather the whey is removed slowly by draining. You can make Mascarpone with tartaric or citric acid, or even lemon juice. Tartaric acid seems to produce the best flavor.
Place the cream in the stainless bowl and set over the double boiler.
Adjust the heat under the pan to medium, and heat the cream, checking the temperature often with an instant-read thermometer, to 190°F, stirring occasionally.
Stir in the tartaric acid, continuing to stir gently until the cream begins to curdle. It will look a bit like Cream of Wheat. Remove the pan from the heat, cover, and allow the curds to firm up for 10 minutes.
Line a strainer or colander with dampened cheesecloth, or butter muslin. Ladle the curds into the strainer and drain for an hour. Allow the Mascarpone to cool to room temperature, cover the strainer tightly with plastic wrap.
Refrigerate for 24 hours to allow the cheese to finish draining and become firm. Then scape into a clean bowl, stir in the salt, and cover. Store in the refrigerator and use within a week or so.
Note: Mascarpone adapts very readily to sweet or savory additions to make a cheese spread. After step 5, try stirring in combinations like minced fresh rosemary with a little red wine or some honey with a pinch of cinnamon.