Not sure what creme fraiche is or why you should care?
Consider it a relative of sour cream. Except that while both are white, thick and creamy, creme fraiche is the richer, sexier and more talented relative.
Here's the deal. Like yogurt, sour cream and creme fraiche are dairy products produced thanks to the miracle of friendly bacteria. But while yogurt is made by adding those bacteria to milk, sour cream and creme fraiche are made by adding them to cream.
So what's the difference? Sour cream is made from cream that is 20 percent fat; creme fraiche sports an even more succulent 30 percent.
That may not sound like a big difference, but it matters in both taste and versatility. That extra fat turns creme fraiche into a kitchen workhorse.
But first, taste. While sour cream tastes, well... sour, creme fraiche is rich and tart. And as a byproduct of the bacteria added to produce it, creme fraiche tends to make other foods taste buttery.
But unlike yogurt, creme fraiche isn't particularly acidic (so it's not great for marinades).
The trouble with sour cream is that you have to be very careful when cooking with it. Heat it too much and it curdles. Ditto for yogurt. But the higher fat content of creme fraiche means you can boil with abandon and it won't separate. This makes it ideal for soups, sauces and simmered dishes.
It will, however, liquefy. That means that if you add it to the top of something, then toss it under the broiler (as in the recipe for croque monsieur below), or even just dollop it onto something hot, it will melt.
In France, where it originates, creme fraiche often is used in sauces for vegetables, particularly green beans and cauliflower, as well as in salad dressings, soups and pastries, and to top fresh fruit. It's sometimes used to make caramels and even is added to coffee and cocktails.