I thought crème fraîche only grew in France – i.e. that it was hard to make and only French dairies chose to make it – but it is easy to make and we can make it here. That means we can have it without going to France.
Take 1 pint heavy cream, ideally not ultrapasteurized, and 1-2 tablespoons cultured buttermilk. Combine in a medium saucepan and heat to tepid (85 degrees maximum). Pour into a clean jar. Cover partially and let stand at 65-75 degrees for 8-24 hours or until thickened. Stir, and refrigerate at least 24 hours before using, so that it can continue to thicken and develop flavor. It keeps for about two weeks.
These instructions are from Kathy Farrel-Kingsley’s The Home Creamery, a book which has received mixed reviews. I have not tried any of her recipes, although I will, as I am intrigued, as soon as I can find raw cream.
Axé.
coldhearted scientist وداد 
Here’s another tip from some French acquaintances who cooked at my buddy’s house last year:
Sour cream.
D’oh!
I know, I know. Not the same, the internet will tell you!
Taste, cooking quality, etc…
Right?
I put all that to them and said, “But I swear it’s so different! Everyone says so!”
“Nah,” they insisted. “Works just like it in this, anyway.” (French-style spaghetti carbonara.) “And I’ve tried it in something else–worked great in that, too.”
All this time I’d been avoiding recipes (like French-style carbonara) that called for creme fraiche or mixing whipped cream w/ sour cream, and I coulda just used the sour cream straight. Yeesh.
Yes – I know it works but then there is the possibility of having one’s own crème fraîche … which in itself is totally different …
Hee.
(Though that kind of takes one’s own, well, literally, “fresh cream,” doesn’t it?)