Transform Sour Cream Into Crème Fraîche With One Ingredient

Crème fraîche, which literally means "fresh cream" in French, is essentially cultured with bacteria to thicken it and give it a slightly sour flavor. 

Whether you enjoy it in Europe (where it's unpasteurized) or pasteurized in the U.S., crème fraîche tastes a bit nutty and has a tang to it, which works well as a condiment or garnish for many dishes. It's also often used to thicken sauces or soups. It has many uses and is called for in lots of different recipes, but it may not be one of those staple items you always have in the fridge.

The good news is, if you find yourself in a pinch, it's easy to make your own version of crème fraîche at home. All you need is one ingredient to turn sour cream into crème fraîche: heavy cream. Mix the two together, and you've got a solid substitute that'll get the job done.

Sour cream and crème fraîche are similar in a lot of ways — at the most basic, they are both types of cultured cream. So how exactly are the two dairy products different?

One important distinction is that crème fraîche has a higher fat content and lower protein amount than sour cream. This is what makes it such a great thickener, because it doesn't curdle under heat. Because it's lower in fat and higher in protein, sour cream does curdle — which is why it's used more as a true condiment than a cooking ingredient.

As far as taste and texture, both products are tangy and creamy. But crème fraîche is thicker in consistency, nuttier in flavor, and slightly sweeter than sour cream. Sour cream also has a higher amount of bacterial culture and thus more acidity, which is why it also works well in baked goods. It also tends to have a more liquid-like texture with a more pronounced sour taste to it.

Sour cream and heavy cream both tend to be regulars in the fridge, so this is a great combo to turn to if you need a crème fraîche substitute (especially if you need it quickly). To make crème fraîche this way, all you need to do is combine equal parts of sour cream and heavy cream and use the mixture any way you would with the traditional ingredient.

But, if you have some additional time, you can make traditional crème fraîche at home — and just like the sour cream substitution, you only need two ingredients to do so. Simply mix buttermilk with heavy cream and let the mixture sit, covered, at room temperature for 12 to 24 hours. As an alternative to buttermilk, you can also use yogurt.

The cultures in the buttermilk will slowly add acidity and thicken the heavy cream until it transforms into a tangy true crème fraîche. You can play around with the ratios to adjust the ultimate consistency and time that it takes to sour, but one tablespoon of buttermilk to one cup of heavy cream will usually work well to produce a creamy, tasty result.