To make 1 cup of buttermilk substitute: measure 1 tablespoon of white vinegar (or lemon juice) into a liquid measuring cup, fill with milk to the 1-cup line, stir briefly, and let sit for 5 minutes. Use in any recipe 1:1 in place of real buttermilk.
This works because buttermilk’s two key functions in baking are acidity (which activates baking soda) and tanginess (flavor). The acid-milk combination delivers both.
The 5 best substitutes
1. Milk + white vinegar (quickest, most neutral)
- 1 tablespoon white vinegar
- Milk to fill 1 cup (about 235 mL)
Stir and let sit 5 minutes. The milk will curdle slightly — this is correct. White vinegar has a neutral flavor that doesn’t affect baked goods.
To scale:
- 1/2 cup: 1.5 teaspoons vinegar + milk to 1/2 cup
- 1/4 cup: 3/4 teaspoon vinegar + milk to 1/4 cup
- 2 cups: 2 tablespoons vinegar + milk to 2 cups
2. Milk + lemon juice (same ratio, slightly citrusy)
Same ratio as vinegar — 1 tablespoon lemon juice per cup of milk. Fresh or bottled lemon juice both work. The citrus flavor is usually undetectable in the final baked good, but it pairs especially well in blueberry, lemon, or citrus-flavored recipes.
3. Plain yogurt thinned with milk (richest result)
- 3/4 cup plain yogurt (170 g)
- 1/4 cup milk or water
Whisk until smooth. Use 1:1 for buttermilk. Greek yogurt works if thinned more aggressively — it’s thicker, so use 1/2 cup yogurt + 1/2 cup milk for 1 cup substitute. Yogurt has natural lactic acid that behaves like buttermilk, and it adds fat, which makes baked goods especially tender.
4. Sour cream + milk
- 3/4 cup sour cream
- 1/4 cup milk or water
Whisk until smooth. Sour cream and buttermilk have similar fat content and acidity. This substitute works especially well in pancakes, cakes, and quick breads.
5. Kefir (1:1, no adjustment needed)
Plain, unflavored kefir replaces buttermilk cup-for-cup with no mixing required. It’s already fermented, has a similar tangy flavor, and similar viscosity. Use wherever buttermilk is called for.
Dairy-free options
| Non-dairy milk | Acid | Notes |
|---|---|---|
| Soy milk | 1 tbsp vinegar or lemon juice per cup | Curdles most like dairy; best non-dairy option |
| Oat milk | 1 tbsp vinegar per cup | Doesn’t curdle, but provides the acid |
| Almond milk | 1 tbsp vinegar per cup | Thinner than buttermilk; works in most recipes |
| Coconut milk (canned) | 1 tbsp vinegar per cup | Rich and fatty; good in tropical or chocolate recipes |
What buttermilk does in baking
Understanding the function helps you choose the right substitute:
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Activates baking soda: Baking soda needs an acid to react. Buttermilk (pH around 4.5–4.8) provides that acid. Without the acid, baking soda doesn’t produce CO2 and the recipe won’t rise properly.
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Tenderizes gluten: Acid weakens some gluten bonds, producing a more tender crumb. This is why buttermilk pancakes, biscuits, and cakes have a softer texture than versions made with regular milk.
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Adds tangy flavor: The lactic acid from fermented buttermilk adds depth. Your homemade substitute replicates this with added acid.
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Contributes moisture: Buttermilk is a liquid; any of the substitutes above provide the same liquid volume.
Comparison table
| Substitute | Acid source | Works in |
|---|---|---|
| Milk + vinegar | Added acid | All buttermilk recipes |
| Milk + lemon juice | Added acid | All; slight citrus note |
| Yogurt + milk | Natural lactic acid | Baked goods, pancakes |
| Sour cream + milk | Natural lactic acid | Baked goods, pancakes |
| Kefir | Natural lactic acid | All buttermilk recipes, 1:1 |
| Soy milk + vinegar | Added acid | Dairy-free baking |
All of these work with the baking soda in your recipe because they deliver the acid at the right quantity. The one thing none of them replicate perfectly is the complex flavor from long fermentation — but in most baked goods you won’t notice the difference.
Real buttermilk: how long it keeps
If you buy cultured buttermilk and only need 1 cup, the rest keeps well. Cultured buttermilk sold in US grocery stores (brands like Darigold, Knudsen, or store-brand) typically has a use-by date 2–3 weeks after purchase. Once opened, use it within 7–14 days. It should smell tangy but not rotten; a slightly stronger sour smell is normal as it ages.
Freeze leftover buttermilk in ice cube trays (each cube = about 2 tablespoons) and store frozen cubes in a sealed bag for up to 3 months. Thaw in the refrigerator overnight. The texture becomes slightly grainy after freezing — whisk well before using in baking, where the texture change is invisible.
Adjusting thickness
The acid-milk substitute is thinner than commercial buttermilk. Commercial cultured buttermilk has a fat content of about 1.5% and is viscous, almost pourable-yogurt consistency. The milk-and-vinegar version is thinner, closer to regular milk. This matters in:
- Pancake batter: A thinner substitute can make slightly thinner pancakes. For fluffy pancakes, use the yogurt substitute (3/4 cup yogurt + 1/4 cup milk) — it’s closest in viscosity.
- Biscuits: In biscuit dough, thinner buttermilk can make the dough slightly stickier. Reduce the milk-and-vinegar mix by 2 tablespoons and add them gradually if the dough seems too wet.
- Cakes and muffins: Thickness doesn’t matter — the batter absorbs either.
Buttermilk powder
Dried buttermilk powder (sold by Saco and King Arthur Baking) reconstitutes with water and behaves like real buttermilk in baking. The ratio is typically 4 tablespoons powder per 1 cup water. It stores at room temperature for up to 2 years (check packaging), making it a practical pantry staple for occasional buttermilk recipes. The flavor is very close to fresh, and it works 1:1 in any recipe.