Impress with Your Fermentation Skills

I'm finding it difficult to procure crème fraiche from the grocery stores here in Philly. There are a few places that carry it but most do not.

As a result, I have decided to start making my own. It is so simple and it will highly impress your dinner guests. Imagine... "here is a salmon with dill pesto served with a dollop of homemade crème fraiche". You're gonna knock 'em dead.

Here's how:
For every eight ounces of heavy cream, you’ll need one ounce of buttermilk. Combine these two ingredients with a quick stir, then pour into a glass mason jar, closed with a screw-top lid. Let the filled jar sit out at room temperature for 24 hours to thicken slightly and ferment. Then refrigerate the cheese until cold, even more thickened, and ready to use.