A while ago, I said to stay tuned on how to make your tiramisú truly killer. Well, I know you've been holding your breath, so I'll let you breath now. The secret to a really killer tiramisú is... MAKE YOUR OWN MASCARPONE!!!
"Wha- what?! You're crazy! I can't make mascarpone at HOME! That's why it's so expensive in the grocery store!"
A fresh cheese is called fresh for a reason, and there's nothing fresher than making it yourself. And just like homemade ricotta, it's easier than you think. However, unlike ricotta, it's not something you can do on the fly and there, in fact, is a formula to.
(makes about a pint of cheese, and can be doubled for a quart of cheese)
2 cup heavy cream (NOT ultra-pasteurized)
2 cup half-and-half
1/4 tsp tartaric acid
1 tbsp cool water
In a bowl over gently simmering water, stir together the heavy cream and half-and-half. Clip a thermometer to the bowl and slowly heat, stirring often, to 185º. Meanwhile, in a small dish, stir the tartaric acid into the water to dissolve it. Once the cream is up to temp, pour in the tartaric acid solution and stir the cream gently until it thickens to a cream of wheat consistency or like a creme anglaise. Remove the bowl from the water and let sit undisturbed for 10 minutes. Then pour into a container and fridge overnight.
The next day, line a colander with a double layer of cheesecloth. Gently spoon/pour the mascarpone into the cheesecloth. You will notice the top will be a thick cream and the whey will be the liquid that settled below it. Gather the corners of the cheesecloth together and tie. Suspend the the bag over a bowl (I use a bucket and tie the bag to a long wooden spoon or metal rod) and let the cheese drain in the fridge for 24-48 hours. After that, cut the cheesecloth bag open over a bowl and turn out the cheese. You will notice that what was the top of the cheese is more firm than what was the lower half, so with a spatula homogenize the cheese so it is uniform. Pack into a container and place plastic wrap directly on the surface and cover with a tight lid. The cheese will keep for about a week so you can definitely make it well ahead of what you would need it for.
Homemade mascarpone is looser than the commercial kind, so depending on the application you may find you need to back off on any additional liquid in the recipe, but I haven't noticed a horrible discrepency when substituting homemade for commercial.
"Hey! What the heck is 'tartaric acid'?"
It is an acid most commonly found in winemaking, where it helps control the pH of the must and forms white crystals on the cork and on the inside of the wine barrel. Cream of tartar is a derivative of tartaric acid, they are not the same thing. Tartaric acid can be found at wine and beer supply shops and is not expensive. It is a white powder that looks a little coarser than table salt and is more sour than citric acid.
Oh... and one more thing... it's pronounced mas-CAR-pone. Not MARS-ca-pone. Just sayin'...