Crème fraîche and sour cream are both creamy dairy products commonly used in either sweet or savoury dishes. They’re kind of the same, but different enough to warrant a bit of a dive, so here goes, in fancy bullet points, no less. 

• Crème Fraîche: Contains around 30% fat, making it naturally thicker and richer. It has a mild, slightly tangy flavour with a creamy finish.

• Sour Cream: Contains about 20% fat and is thinner/has less body than crème fraîche. It may contain thickening agents like gelatine however. It has a distinctive, slightly tangy flavour due to the lactic acid bacteria used in its production.

Production and Origin

• Sour Cream: Originating Eastern Europe and Russia, it's made by fermenting regular cream with lactic acid bacteria, which thickens the cream and gives it that characteristic tang.

• Crème Fraîche: A classic French ingredient, the name literally means "fresh cream." Originally made from unpasteurised cream left to sour naturally thanks to bacteria in the milk, nowadays it's made with pasteurised cream and a starter culture used to induce fermentation.

Culinary Uses

• Crème Fraîche: Due to its higher fat content, crème fraîche can be heated without curdling, making it ideal for finishing pan sauces and soups. It's also excellent in savoury tart and quiche mixtures and pairs brilliantly with berries or berry, and other fruit tarts for dessert.

• Sour Cream: You can’t really heat sour cream as it curdles, so it’s best used cold. It’s perfect for dips, dressings, and as a topping for dishes such as tacos and borscht. It is also excellent in baked goods, adding moisture to cakes, muffins, and other desserts. Some claim it also adds ‘tang’ but we don’t know that you can exactly taste it in a cake or whatever.

Nutritional Aspects

• Crème Fraîche: Higher in fat and calories due to its richer composition. It also provides beneficial probiotics from the fermentation process.

• Sour Cream: Lower in fat and calories but still offers a good source of probiotics and can be a lighter option for recipes that don’t require heating.

Storage Tips

• Both crème fraîche and sour cream should be stored in the refrigerator. Once opened, they typically last for about a week to ten days. Ensure the lid is tightly closed to prevent contamination and maintain freshness.

Substitutions

• Crème Fraîche for Sour Cream: In cold dishes, you can substitute crème fraîche for sour cream if you want a richer, less tangy flavor. In hot dishes, crème fraîche is a better option due to its stability when heated.

• Sour Cream for Crème Fraîche: Sour cream can be used as a substitute for crème fraîche in cold applications or baked goods where the tanginess and lower fat content will not affect the outcome negatively.

Typical Dishes

• Crème Fraîche: Used in sauces and soups (like creamy mushroom sauce), desserts (with fresh berries or in tarts), and savoury dishes (like quiche Lorraine).

• Sour Cream: Popular in dips (like onion dip), dressings (such as ranch), and as a topping for dishes (such as baked potatoes, tacos, and borscht). It's also used in baking.