Learn how to make an easy homemade buttermilk substitute for baking recipes, as well as what buttermilk does for baked goods, why it’s required in some baking recipes, and more about the unique properties of this curious ingredient. My team and I tested several substitutes including regular milk, DIY soured milk, sour cream, kefir, and powdered buttermilk.

Welcome back to my baking tips series. If you’ve ever wondered what certain ingredients do in baking, when to use them, and why, this is where I share what I’ve learned. Like what’s the difference between baking powder vs. baking soda, or Dutch-process vs. natural cocoa powder? Today we’re exploring the whats, whys, and hows of buttermilk.

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What Is Buttermilk?

Buttermilk is fermented milk. Traditionally, it was a byproduct of making butter; the liquid leftover after churning fat out of cream was left out to ferment. Nowadays, the kind of buttermilk you can buy in the grocery store is made in a controlled environment by adding bacteria to milk, which produces lactic acid.

While I don’t exactly crave a tall glass of buttermilk to wash down my cookies, I often have it in my refrigerator because it’s a key ingredient in so many baking recipes.

How to Make a Buttermilk Substitute

Because of buttermilk’s unique contributions to baking recipes, you shouldn’t simply substitute regular milk, especially if there is baking soda in the recipe.

Instead, you can make a homemade DIY buttermilk substitute or “DIY soured milk” by adding an acid—either white vinegar or lemon juice—to regular milk and letting it sit for a few minutes. This simple step only adds about 5 minutes to your baking prep time, and makes a BIG difference in your finished baked good. It’s a fine substitute in recipes that call for less than 1 cup of buttermilk.

You’ll find the instructions in the printable recipe card below, but here’s an overview of the process:

Add 2 teaspoons of white vinegar or lemon juice to a liquid measuring cup. Then add enough whole milk to the same measuring cup until it reaches 1 cup. Stir it around and let sit for 5 minutes. The homemade “buttermilk” will be somewhat soured and curdled and ready to use in the recipe.

Success Tip: I typically use low-fat buttermilk, which is plenty thick (there’s really no discernible difference between whole and low-fat buttermilk in the finished baked goods), but if you’re making this DIY buttermilk substitute, I strongly recommend using whole milk. Low-fat or nondairy milks work in a pinch, but your cakes/muffins/biscuits won’t taste as moist or rich. Avoid using nonfat milk.

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Side-by-Side Comparisons

Baking science experiment time! To explore the difference buttermilk makes in the taste and texture of baked goods, and determine the best substitute to use if you don’t have any on hand, my team and I tested 3 different recipes, each made 4 times exactly the same way but with 1 ingredient change:

1. Store-bought buttermilk (our “control”)
2. DIY homemade buttermilk substitute (white vinegar + whole milk)
3. Whole milk
4. Powdered buttermilk + water

We tested these 4 ingredients in my recipes for cornbread muffins, strawberry shortcake biscuits, and no-yeast bread (soda bread).

Note: For the powdered buttermilk test recipes, we followed the package’s instructions, mixing the powder into the dry ingredients, and the water into the wet ingredients. The package didn’t mention mixing the powder with water first, which would have obviously helped dissolve the powdery chunks we tasted in some of these bakes.

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Cornbread Muffins Test

First, let’s look at the cornbread muffins:

The whole milk muffins rose surprisingly high with a tall peak, and were a little more crumbly and dry. There wasn’t enough acid in this batter, so there was leftover baking soda that wasn’t neutralized, which left a slightly bitter aftertaste.

The real buttermilk muffins looked the way we expected and they tasted the best.

The powdered buttermilk muffins tasted sour—the flavor was definitely off. They also had a denser texture and didn’t rise as high.

The DIY buttermilk muffins yielded a similar result to the real buttermilk. They were great!

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Shortcake Biscuits

Now let’s take a look at the shortcake biscuits:

The whole milk shortcake biscuits looked good, but were lacking flavor and tasted a bit flat.

The real buttermilk shortcake biscuits rose beautifully, with lots of flaky layers, and browned nicely on top.

The powdered buttermilk shortcake biscuits had chunks of orange-colored powder clumps, which didn’t dissolve properly. They also spread more, didn’t rise as high, and didn’t produce as many flaky layers.

The DIY buttermilk biscuits rose as high as the real buttermilk biscuits and had nice flaky layers; the flavor was good and these tasted most similar to the real buttermilk biscuits.

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No Yeast Bread

Finally, let’s look at the recipe that calls for the most buttermilk, which is this no-yeast bread:

The whole milk no-yeast bread had an incredibly dense texture, bordering on “hard as a brick.” It was also lacking in the flavor department. This recipe NEEDS the acidity of buttermilk.

The buttermilk no-yeast bread came out nicely shaped and browned, with a dense yet moist texture, crusty exterior, and rich flavor as intended.

The powdered buttermilk no-yeast bread over-spread a significant amount, and once again the powder didn’t fully dissolve so there were visible chunks of it throughout. It also had a particularly sour flavor.

The DIY buttermilk no-yeast bread rose and browned nicely and tasted good. This is a naturally dense bread because the only leavening comes from the buttermilk’s acid + baking soda, but the crumb of this loaf was slightly denser than the one made with real buttermilk.

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What About Using Sour Cream or Yogurt?

We went one step further in this test and tried the shortcake biscuits with a sour cream and whole milk combination to produce a DIY buttermilk substitution. This substitution can work most of the time. For every 1 cup of buttermilk, you can use 1/2 cup (120g) full fat sour cream or whole milk yogurt and 1/2 cup (120ml) whole milk.

But keep in mind that the results may not be the same compared to using real buttermilk.

In particular, with the shortcake biscuits, they weren’t as tangy and they had a fluffier, less flaky texture. They were still delicious—they just lacked the intended flavor and texture. In recipes where you want a fluffy, soft texture, you could easily use this sour cream/milk substitution instead of buttermilk.

What about using kefir instead of sour cream? I’ve used kefir as a 1:1 substitute for buttermilk in scones and cupcakes and it works very well. If you happen to have kefir and not buttermilk, you can absolutely use it. In fact, pastry chef Stella Parks has written that it’s one of her favorite buttermilk subs.

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In Conclusion

All the baked goods made with regular store-bought buttermilk had the best taste and texture. The DIY homemade buttermilk substitute came in second place. It gave the baked goods a similar texture and flavor and is my preferred alternative, but only if you can’t get your hands on the real thing. The sour cream/milk combination works too, but you’ll notice a cakier/fluffier texture (which isn’t a bad thing in some cakes, cupcakes, etc). Kefir can work as a 1:1 substitute if you have it on hand. However, in baking recipes that require more than 1 cup of buttermilk, I strongly recommend using real buttermilk because using alternatives will likely compromise the flavor and texture.

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How Can I Use Buttermilk?

Here are all of my recipes that call for buttermilk. The following are some of my very favorites:

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