Creme fraiche (crème fraîche) is cultured cream: cream thickened by a live culture until it is spoonably soft and mildly tangy, with 30-40% fat. That high fat is the point — unlike sour cream, it does not curdle when boiled, so you can stir it straight into a bubbling sauce. In cold dishes, sour cream or full-fat Greek yoghurt substitute for it 1:1.
You're mid-recipe, the list says creme fraiche, and the tub in your fridge says sour cream. Here's what creme fraiche actually is, when the swap works, when it splits, and how to culture a batch yourself overnight.
| Substitute | How much | Watch out for |
|---|---|---|
| Sour cream | 1:1 | Only 18-20% fat — it curdles if boiled. Cold dishes, or stir in off the heat. |
| Full-fat Greek yoghurt | 1:1 | Cold uses. For a hot dish, stabilise with 1 tsp cornstarch (cornflour) per 150 g first. |
| Mascarpone | 1:1, thinned with a little milk | Rich and smooth but barely any tang. |
| Homemade creme fraiche | 240 ml (1 cup) heavy cream + 2 tbsp cultured buttermilk | Needs 12-24 hours at warm room temperature — start it the day before. |
What Creme Fraiche Actually Is
Creme fraiche — crème fraîche, if we're being proper — is cultured cream. A dairy culture is stirred into cream and left to work, much as yoghurt is made from milk. The culture thickens it to a soft, spoonable set and gives it a mild tang. Nothing else goes in.
It sits at 30-40% fat, which makes it noticeably richer than sour cream and far richer than yoghurt. The flavour is gentle: fresh cream first, a little pleasant sourness behind. In the US you'll find it in small tubs near the sour cream; in Britain and Ireland it's in every supermarket chiller.
The Headline Trick: It Will Not Curdle
Here is why cooks reach for it. That 30-40% fat protects the cream when it's heated, so creme fraiche does not curdle in a boiling sauce. Stir it into a simmering soup, a bubbling pan sauce or a hot gratin and it stays smooth and glossy.
Sour cream cannot do this. At 18-20% fat there isn't enough richness to protect it, and it splits into grainy curds once the sauce boils. So the rule is simple: if the dish is hot, use creme fraiche. If it's cold, either will do.
Creme Fraiche Substitutes
No tub in the fridge? The table below has you covered. Sour cream is the nearest match at 1:1 — same tang, same job — but it curdles if boiled, so keep it for cold dishes or stir it in off the heat. Full-fat Greek yoghurt also swaps 1:1 in cold uses; if it must go into something hot, stabilise it first with 1 tsp cornstarch (cornflour, to us) per 150 g and it will hold. Mascarpone thinned with a little milk gives you the richness without much tang. Be honest with yourself, though: in a properly boiling sauce, only creme fraiche — bought or homemade — does the job without fuss.
How to Make Creme Fraiche at Home
You can culture your own with two ingredients. Stir 2 tbsp cultured buttermilk into 240 ml (1 cup) heavy cream — double cream, in the UK. Cover the jar and leave it at warm room temperature for 12 to 24 hours, until it has set thick. That's it; the live cultures in the buttermilk do all the work. Chill it once it's set, then use it anywhere a recipe calls for creme fraiche — boiling sauces included.
Where It Shines
Dolloped, stirred or spooned. A spoonful on hot soup instead of a swirl of cream — it won't split on you. On chili or a baked potato, wherever an American recipe says sour cream, it does the same job with more richness. Stirred into a pan sauce at the end for instant gloss. And with sharp fruit puddings — rhubarb, berries, apple — that mild tang cuts the sweetness better than whipped cream ever did.
Questions we get asked
Is creme fraiche the same as sour cream?
No, though they're cousins. Both are cultured, but sour cream sits at 18-20% fat and curdles if it boils. Creme fraiche is 30-40% fat, milder in tang, and holds together in a hot sauce. In cold dishes they swap 1:1.
Can you boil creme fraiche?
Yes. Its 30-40% fat protects it, so it does not curdle in a boiling sauce — that's the very reason cooks buy it. Stir it into simmering soups, pan sauces and gratins without worry.
What does creme fraiche taste like?
Mildly tangy, rich and smooth — fresh cream first, a gentle sourness second. It's milder and thicker than sour cream: soft enough to swirl, thick enough to hold a spoon.
What can I use instead of creme fraiche?
Sour cream, 1:1, in cold dishes — it curdles if boiled. Full-fat Greek yoghurt, 1:1, cold, or stabilised with 1 tsp cornstarch (cornflour) per 150 g if it's going into heat. Mascarpone thinned with a little milk where you want richness without much tang.
Can I make creme fraiche at home?
Yes. Stir 2 tbsp cultured buttermilk into 240 ml (1 cup) heavy cream, cover, and leave at warm room temperature for 12 to 24 hours until thickly set. Chill before using.
Is creme fraiche the same as clotted cream?
No. Clotted cream is a Devon and Cornwall speciality made by gently heating cream for hours until a thick golden crust forms — 55-64% fat and spoonable-solid, made for scones and jam. Creme fraiche is cultured, mildly tangy, and much softer.