What can I use instead of buttermilk, soured cream or crème fraîche?

Buttermilk, soured cream, crème fraîche, yoghurt and kefir are all cultured dairy and they overlap heavily. What separates them is fat content and acidity, and those two numbers decide whether a substitute will work in your particular recipe — especially whether it will survive being heated.

Step by step

1. Work out whether the recipe needs the acid or the body.Anything raised with bicarbonate of soda needs the acid — that is the whole reason buttermilk is there, and the soured-milk substitute is a straight match. A dip, a topping or a sauce enrichment needs the body, and soured milk will be useless.
2. Check whether it gets heated.This is the decision that catches people out. Yoghurt, soured cream, half-fat crème fraîche and buttermilk all split if boiled. Full-fat crème fraîche and double cream do not. If the substitute goes into a simmering pan, that narrows the list sharply.
3. Make soured milk properly.A tablespoon of acid per 240ml of milk — lemon juice, white wine vinegar or cider vinegar all work. Leave it ten minutes at room temperature; it should look slightly curdled and thickened. Use it as it is, curdles and all.
4. Match the fat where texture matters.Low-fat yoghurt in place of full-fat soured cream makes a thin, sharp, watery result. Where the substitute is providing richness, use the full-fat version of whatever you are substituting.
5. Add cold cultured dairy off the heat.Take the pan off, let it stop bubbling, stir a ladle of the hot liquid into the yoghurt or soured cream to temper it, then stir that back in. This works for almost any cultured dairy in almost any sauce.
6. Stabilise it if it must be cooked.A teaspoon of cornflour whisked into yoghurt before it goes into a hot pan, added slowly with constant stirring, keeps it from splitting. It is how yoghurt-based sauces are cooked in cuisines that use them routinely.

Tips

• Traditional buttermilk — the liquid left after churning butter — is a different, thinner thing from the cultured buttermilk sold in cartons. Recipes almost always mean the cultured kind.
• Buttermilk freezes well and thaws slightly separated. Shake it hard. It is worth freezing in 240ml portions if you buy a carton for one recipe.
• Buttermilk is an outstanding marinade for chicken. The acidity is mild enough that it tenderises over hours without turning the surface to mush the way lemon juice does.
• If a recipe uses both buttermilk and baking powder, the buttermilk is there for flavour and tenderness as much as lift, and a plain milk substitute will make a noticeably less good result.
• Leftover soured cream and crème fraîche both freeze poorly. Use them in a soup or a traybake rather than saving them.

Common mistakes

• Using milk with no acid in a soda bread recipe — Bicarbonate of soda needs an acid to react with. Without it the bread does not rise and tastes soapy. The lemon or vinegar is not optional.
• Boiling a sauce after adding yoghurt — Yoghurt's whey proteins coagulate well below boiling and it goes grainy. Off the heat, tempered, stirred in at the end — every time.
• Substituting half-fat crème fraîche for full-fat in a hot dish — The stability comes from the fat. The half-fat version splits in a pan just as readily as soured cream does.

Alternatives

• Soured milk — for buttermilk in baking: One tablespoon of lemon juice or white vinegar stirred into 240ml of milk, left ten minutes until slightly thickened. It matches the acidity, which is what the bicarbonate of soda needs, but not the thickness. The standard and entirely adequate substitute for scones, soda bread and pancakes.
• Thinned yoghurt — for buttermilk with body: Natural yoghurt let down with milk to a pourable consistency, roughly three parts yoghurt to one part milk. Closer than soured milk in both acidity and texture, and better in a marinade or a dressing.
• Kefir — a near-direct buttermilk substitute: Similar acidity, similar consistency, more complex flavour. Works one-for-one in baking and in marinades. Increasingly easy to buy and cheap to keep going at home.
• Full-fat Greek yoghurt — for soured cream, cold: Similar thickness and tang, less fat. Ideal on a baked potato, in a dip or stirred into a chilli off the heat. It will split if boiled, so it is a cold substitute unless you stabilise it.
• Crème fraîche — for soured cream, hot or cold: Richer and less sharp than soured cream but it behaves the same cold, and unlike soured cream the full-fat version can be boiled. The best substitute when the dish gets heated.
• Double cream with lemon — for crème fraîche: Double cream with a squeeze of lemon juice, stirred and left a few minutes. Matches the fat and gets some of the acidity. It does not have the cultured flavour, but it survives heat and is the emergency version.
• Cream cheese thinned with milk — for soured cream in a dip: Beat cream cheese with enough milk to loosen it and a squeeze of lemon. Thicker and milder, good in dips and cheesecake-adjacent uses, poor anywhere the tang is the point.

Questions people ask