Success!!! I made up a batch of crème fraiche last night, let it do its culture thing overnight and put it in the fridge before work. I followed the directions as closely as humanly possible and the results paid off. When I got home from work, waiting for me in the fridge was a slightly sweet, slightly tangy, albeit a bit runny, near-perfect batch of crème fraiche! What a relief to know it works. I'm going to whip up another batch this evening, this time using a little bit more starter to see if I can get it to thicken up a little bit more (plus then I'll have some to enjoy at home). Now just to figure out the best way to serve it.