Today I made mascarpone using my kit. It came out well, but not perfectly, and I have a few ideas as to why that might have been.
For one thing, in a hurry at the store this morning I picked up UHT cream instead of pasteurised. That it worked at all given that it was the wrong type of cream is amazing, but I'd like to see how it turns out at some point with the right cream.
Another possible reason is that a minute of inattention at the end of heating the cream led to it being 10°C too hot, 95° instead of 85°. I don't know how temperature sensitive cheese making generally, and mascarpone in particular, are. The temperature rose quite quickly too, and I don't know whether this is desirable or whether it should have been a slower temperature increase.
The final thing is that initially I only lined my colander with a single thickness of cheese cloth and the 'whey' coming out was almost as thick as cream. I then tried to double over my cheese cloth while it was full of curdled cream which made a bit of a mess (although surprisingly not as much as I might have expected). It is now draining over a clean bowl and clean, doubled, cheese cloth and it is draining much better with the whey looking more as it should.
Over all, it worked ok, and I used it in a variation of Yotam Ottolenghi's butternut and mascarpone tart, which was very tasty, so for my purposes the mascarpone worked well. Remains to be seen what happens when I don't mess it up...
EDIT: Having left the mascarpone to drain further for a few more hours, it came out thick and creamy and beautiful. I do wonder what it would have been like had I not messed up a couple of steps, but it is a point in favour of the recipe that it shows such resilience. The whey too now looks more as it should. Hurray!
EDIT 2: This recipe made A LOT of mascarpone. 1 l of cream produced 700g (roughly) of mascarpone, so I had to find a series of creative ways of using it: in the tart (above), in hot chocolate, on muffins, in crêpes with a balsamic and honey drizzle... I might make only a half batch next time.