Crème fraîche

Crème fraîche is cream that has been thickened and soured by lactic acid bacteria. It is spoonable, rich and mildly tangy, less sour than sour cream. Because it is high in fat, usually around 30 to 40 percent, it can be boiled without splitting, which makes it very useful in hot sauces.

How to use it

• Stir it into a pan sauce, soup or pasta sauce and let it bubble to thicken.
• Spoon it onto potatoes, smoked fish, soups and blinis.
• Serve it with fruit tarts, crumbles and berries in place of whipped cream.
• Whip it. Chilled crème fraîche whips to soft peaks in a minute or two.

Substitutes

• Heavy cream (whipping cream in the UK) with a squeeze of lemon. It will not be as thick, but it behaves well in hot sauces.
• Sour cream works cold. In a hot sauce it can curdle, because it has less fat. Stir it in off the heat.
• Gräddfil, the Swedish sour cream, is lower in fat and also splits when boiled.
• Mascarpone loosened with a little lemon juice, for desserts.

To make your own, stir 2 tablespoons of buttermilk into 250 ml (1 cup) of heavy cream in a clean jar. Cover loosely and leave at warm room temperature for 12 to 24 hours, until thick. Chill before using. It thickens more in the fridge.

How to store it

Keep it in the fridge and use an opened tub within about a week. A little liquid on top is fine to stir back in. Throw it out if you see mold or it smells bitter or yeasty.

In recipes

French recipes use crème fraîche where English recipes might use cream or sour cream. Swedish recipes use it a lot for sauces, because it does not split. Light versions of crème fraîche have less fat and can split when boiled, so use full-fat for hot dishes.