The best buttermilk substitutes depend on what you're baking

You can replace buttermilk with regular milk mixed with an acid, or with yogurt, sour cream, or kefir thinned with water. The choice depends on what you're making—a tender cake needs different chemistry than a tangy salad dressing. Most substitutes work in a 1:1 ratio, though some need thinning first.

Buttermilk's job in a recipe is twofold: it adds moisture and tang, and its acidity reacts with baking soda to create lift. When you swap it out, you're replacing both those functions. The acid matters most in recipes that rely on baking soda for rise (pancakes, biscuits, quick breads). The tang matters more in dressings and marinades where flavor is the point.

Key Takeaways

  • Milk plus lemon juice or vinegar is the fastest substitute and works in almost any recipe that calls for buttermilk.
  • Yogurt or sour cream thinned with water gives you tang and moisture without extra steps, though you may need to reduce other liquids slightly.
  • For baking soda recipes (biscuits, pancakes, cakes), the acid in your substitute matters as much as the liquid itself.
  • Let milk-and-acid mixtures sit for 5 to 10 minutes before using so the acid has time to curdle the milk slightly.

Milk plus lemon juice or vinegar

This is the most reliable substitute and the one that most closely mimics buttermilk's behavior. Mix 1 cup of whole milk with 1 tablespoon of fresh lemon juice or white vinegar. Stir and let it sit at room temperature for 5 to 10 minutes. The acid will cause the milk to curdle slightly and thicken, creating a liquid that behaves almost identically to buttermilk in baking.

Use this substitute in a 1:1 ratio for any recipe. It works equally well in pancakes, biscuits, cakes, and quick breads. The acid reacts with baking soda the same way buttermilk does, so you won't lose any rise. If you're using 2% or skim milk instead of whole milk, the result will be slightly thinner, but it still works—just expect a marginally less tender crumb in cakes.

The main mistake is not waiting those 5 to 10 minutes. If you mix and use when ready, the milk hasn't curdled yet and won't perform the same way. Set a timer or move on to another prep task while it sits.

Plain yogurt or Greek yogurt thinned with water

Yogurt is thicker than buttermilk, so you need to thin it. Mix equal parts yogurt and water—for example, 1/2 cup yogurt plus 1/2 cup water to replace 1 cup buttermilk. Stir until smooth. Plain yogurt works better than flavored varieties, and Greek yogurt (which is much thicker) needs more water than regular yogurt.

This substitute adds tang and moisture, and the acidity will still react with baking soda. Use it in a 1:1 ratio in your recipe. Yogurt-based substitutes work especially well in pancakes, muffins, and coffee cakes where the tang is a bonus. In layer cakes, the result can be slightly denser than with buttermilk, but the difference is usually small enough that most people won't notice.

One adjustment: if your recipe already calls for a lot of liquid (like a thin batter), reduce the water slightly or use less of the yogurt mixture, because yogurt adds more moisture than buttermilk does. Start with 3/4 cup of the mixture instead of a full cup, then add more if the batter looks too thick.

Sour cream thinned with water or milk

Sour cream is even thicker than yogurt, so you'll need to thin it more. Mix 1 part sour cream with 1 part water (or milk for richer flavor) to replace buttermilk in a 1:1 ratio. For example, 1/2 cup sour cream plus 1/2 cup water equals 1 cup buttermilk substitute.

Sour cream brings both tang and richness, making it ideal for biscuits, scones, and pound cakes where a tender, rich crumb is the goal. The acidity works with baking soda just like buttermilk does. Because sour cream is richer than buttermilk, baked goods made with this substitute tend to be slightly more tender and have a finer crumb.

The downside is that sour cream can make batter thicker than you expect. Stir the mixture well before measuring, and if your batter looks too stiff, thin it with a tablespoon of milk at a time. This substitute is less forgiving than milk-and-acid if you get the ratio wrong.

Kefir (plain, unsweetened)

Kefir is a fermented milk drink that's thinner than yogurt and already tangy. You can use it almost straight—just thin it slightly with water if it's thicker than buttermilk. Mix 1 cup kefir with 1 to 2 tablespoons of water, depending on how thick your kefir is.

Kefir has natural acidity and will react with baking soda the same way buttermilk does. It works in any recipe that calls for buttermilk and produces results nearly identical to using the real thing. The tang is slightly different (kefir tastes more yeasty), but most people won't detect the difference in baked goods.

The main limitation is availability. Kefir is less common than milk or yogurt and costs more. It's worth buying if you bake with buttermilk regularly, but it's not a practical substitute if you only need it once.

What to avoid and why

Avoid using regular milk alone, even if your recipe doesn't call for baking soda. Milk lacks the acidity that gives buttermilk its tang and its chemical reactivity. In recipes that use baking soda (most quick breads and pancakes), regular milk won't create the same rise. In recipes that use baking powder instead, regular milk will work, but the result will taste flat and bland.

Avoid sweetened or flavored yogurts and kefirs. The added sugar changes the recipe's balance, and vanilla or fruit flavors can clash with savory applications like marinades or salad dressings. Always use plain, unsweetened versions.

Avoid coconut milk or other non-dairy milks unless you're making a recipe specifically designed for them. Coconut milk is too thick and too rich; almond milk and oat milk lack the body and acidity you need. If you're baking dairy-free, look for recipes written for that purpose rather than trying to force a substitute.

Timing and temperature notes

Most buttermilk substitutes work best at room temperature. If your milk-and-acid mixture is cold when you add it to batter, the acid may not have fully activated. Let it sit on the counter for 5 to 10 minutes before using, even if you're in a hurry.

For yogurt and sour cream substitutes, stir them well before measuring. These products can separate slightly, and you want an even mixture. If you're making a large batch of pancakes or muffins, prepare your substitute a few minutes ahead so it reaches room temperature.

In recipes where buttermilk is mixed into dry ingredients (like biscuit dough), temperature matters less. In recipes where it's mixed into wet ingredients or batter, room temperature helps the substitute blend smoothly and perform consistently.

Frequently Asked Questions

Can I use regular milk if I add baking powder instead of baking soda?

Yes, but the result won't taste the same. Baking powder contains its own acid, so it will create lift without buttermilk. However, you'll lose the tang that buttermilk adds. The baked good will taste flatter and less interesting. If your recipe specifically calls for buttermilk, it was designed for that tang, so a substitute with acid (like milk plus lemon juice) is still better.

How long can I store milk mixed with lemon juice or vinegar?

Use it within 30 minutes of mixing. The acid will continue to curdle the milk, and after about an hour it starts to separate noticeably. If you're making a large batch and need to prepare ahead, mix the milk and acid just before you start baking, not the night before.

Will my biscuits rise the same way with a substitute?

Yes, if you use a substitute with acid (milk plus lemon juice, yogurt, sour cream, or kefir). The acid reacts with baking soda to create carbon dioxide, which creates the rise. Regular milk alone will not produce the same lift. The texture might be slightly different—substitutes can make biscuits marginally more tender or slightly denser—but the rise itself will be comparable.

What if I don't have lemon juice or vinegar for the milk substitute?

Use whatever acid you have on hand: lime juice, orange juice, or even cream of tartar (1/2 teaspoon per cup of milk). Apple cider vinegar, rice vinegar, or any other vinegar works. Avoid balsamic vinegar or flavored vinegars that might change the taste of your recipe. If you have no acid at all, yogurt or sour cream is your next best option.

Can I use buttermilk powder instead?

Yes. Mix buttermilk powder with water according to the package directions—usually 1/4 cup powder plus 1 cup water. Let it sit for a few minutes so the powder fully hydrates. Buttermilk powder is shelf-stable and works identically to liquid buttermilk, making it a good option if you bake with buttermilk often.