I have lots of great recipes that call for crème fraîche, but for some reason, it's very difficult to find it in my neighborhood. I hear that sour cream is an acceptable substitute. However, in my view, if whoever originated the recipe wanted to use sour cream, they'd have called for sour cream in the first place! So I don't want to just substitute sour cream for crème fraîche by default.
I have also heard that many types of yogurt can be used, or crema mexicana, or many other products. I imagine that certain products are better in certain recipes than others, in terms of substitution. What are the properties of crème fraîche that can be emulated by which other products?
Best Answer
You can make your own crème fraîche. Just inoculate heavy cream with buttermilk. From The Splended Table:
The results from doing that are so close to "real" crème fraîche that I can't tell the difference unless I'm tasting them side by side. If you want absolute authenticity, you can order the Real Culture, follow their instructions, then use that crème fraîche to culture many further batches of real Crème fraîche.
EDIT: HA! :) Here's Kenji's $.02 on the subject: Serious Eats