Buttermilk is one of the most commonly searched baking substitutions. Here's every reliable replacement — and exactly how to use it.
Buttermilk has a history that stretches back centuries. Traditionally, it was the liquid left behind after cream had been churned into butter — thin, slightly sour, and rich in lactic acid from naturally occurring fermentation. Before refrigeration, this natural culturing process happened unavoidably as cream sat at room temperature before churning. The result was a tangy, acidic liquid that bakers quickly discovered had remarkable properties in the kitchen.
Today, almost no commercial buttermilk is a by-product of butter-making. Modern cultured buttermilk is produced by introducing live bacterial cultures — similar to those used in yogurt — to low-fat or whole milk. The bacteria produce lactic acid, which gives buttermilk its characteristic tang and slightly thick consistency.
Buttermilk does three things in baking that no other single ingredient does simultaneously: it tenderises gluten (making baked goods soft), activates baking soda (providing lift through an acid-base reaction that produces carbon dioxide), and contributes a subtle tang that balances sweetness.
Classic uses include buttermilk pancakes, buttermilk biscuits, fried chicken marinades, red velvet cake, Irish soda bread, ranch dressing, and Southern-style cornbread. In fried chicken, the acidity tenderises the meat while the proteins help the coating adhere.
The critical thing to understand when substituting is that the acidity is the most important property to replicate — not the flavour. Any substitute that provides the right level of acid will perform the leavening and tenderising functions correctly.
Buying: Look for cultured buttermilk with live cultures listed in the ingredients. Full-fat and low-fat versions are interchangeable in most recipes. Avoid powdered buttermilk for fresh baking applications — it lacks the moisture needed and behaves differently.
Storing: Buttermilk keeps 1–2 weeks in the refrigerator. If you buy a full carton for one recipe, freeze the remainder in an ice cube tray (2-tablespoon portions) for future use.
The most reliable DIY substitute. The lemon juice provides the acid needed to react with baking soda and tenderise gluten. Add 1 tablespoon of fresh or bottled lemon juice to a measuring cup, fill to the 1-cup line with milk, stir gently, and let sit for 5 minutes. The milk will curdle slightly — that is correct and means the substitute is working. Use immediately.
Functionally identical to the lemon juice version. White vinegar is more neutral in flavour, making it marginally preferable in recipes where a slight lemon note would be unwanted. The same 5-minute resting period applies.
Greek yogurt is already fermented and acidic — it replicates buttermilk's tang most faithfully of all substitutes. Thin it with milk to reach a pourable consistency. This substitute performs exceptionally well in cakes and muffins where moisture content matters.
Similar to the Greek yogurt version but richer. Sour cream has a higher fat content which adds tenderness to baked goods. Works particularly well in coffee cakes and chocolate cakes where richness is welcome.
Oat milk curdles more readily than other plant milks when acid is added, which makes it the best dairy-free base for a buttermilk substitute. The result is thinner than dairy buttermilk but provides the necessary acidity for leavening. Almond milk and soy milk also work — soy milk is the most protein-rich option and curdles most similarly to dairy.
Kefir is fermented milk with a flavour profile very close to buttermilk — tangy, acidic, and slightly effervescent. Plain, drinkable kefir can be used as a 1:1 buttermilk substitute without any modification.
Regular plain yogurt (not Greek) can be used at a 1:1 ratio since its consistency is closer to buttermilk. Greek yogurt needs thinning; regular yogurt typically does not.
Dairy-free: Oat milk, soy milk, almond milk, or coconut milk + acid all produce dairy-free buttermilk substitutes. Soy milk produces the most protein-rich result and curdles most similarly to dairy.
Vegan: Same as dairy-free above. All options are vegan.
Gluten-free: All substitutes listed are gluten-free.
Low-fat: Low-fat milk versions are lower in fat. Greek yogurt versions are higher in protein and lower in fat than full-fat dairy buttermilk.
Heart health: Oat milk versions significantly reduce saturated fat compared to full-fat dairy buttermilk.