How to Make Buttermilk

Your Pancakes Will Thank You

Buttermilk

The Spruce / Zorica Lakonic 

We've all been there before. You've got the bowls and whisk out, are elbow deep in flour, sugar, salt, eggs, baking powder, baking soda, and chocolate chips, and are ready to start dropping pancakes like it's hot, when you realize that you don't have the star ingredient for your pancake batter: buttermilk.

What do you do? Do you go out to the store just for one ingredient? Do you just add regular milk and hope nobody notices the buttermilk pancakes are sans buttermilk? What is buttermilk anyway and is it really that important?

With hungry kids and plans for a nice weekend family breakfast about to be deflated, here are a few easy, quicky solutions to this common cooking dilemma.

What Does Buttermilk Do?

So, what does buttermilk actually do? The main reason a recipe will call for buttermilk—apart from the tart flavor and creamy thickness that the buttermilk provides—is the acid. The acid in buttermilk is a byproduct of the fermentation process and it will activate baking soda or baking powder, causing your bread, muffins, or pancakes to rise.

So, to answer your question, yes, buttermilk truly is that important.

Not to fear, though. If you don't have any buttermilk on hand and you're in a bind, there are four different ways to make your own buttermilk at home and salvage your recipe (and your cooking reputation).

Illustration for Easy Ways to Make Buttermilk
The Spruce / Catherine Song

The best method for you will depend on what you need it for, and how soon you need it.

Using the first two methods described below, you can make your own buttermilk substitute in 10 minutes or less, which is perfect for those life moments when you're in the midst of making the recipe and realize that you don't have any buttermilk in your fridge.

The second two methods will take longer, but they will save you an unneeded trip to the grocery store and some money.

So let's take a look at what the four methods to making your own homemade buttermilk are.

Lemon and milk
The Spruce / Zorica Lakonic 

How to Make Buttermilk With Vinegar or Lemon Juice

This first method is a really easy method. Just add one tablespoon of lemon juice or vinegar to one cup of milk and let it sit out at room temperature for about 10 minutes. If you need more than a cup, just keep the ratios the same. For two cups, use two cups of milk and two tablespoons of lemon juice or vinegar and so on.

As we noted, this method will not give you a true cultured buttermilk, but rather, acidified buttermilk. This means you can use it in a recipe for biscuits or pancakes or the like, and the acid will activate the baking powder or baking soda just as it should.

Yogurt
The Spruce / Zorica Lakonic 

How to Make Buttermilk From Yogurt

Another fast and simple method calls for taking 3/4 cup of yogurt or sour cream and thinning it out with 1/4 cup of milk (or even plain water). This will make a cup of "buttermilk," although just like the first method, it's not a true buttermilk, but it will be an adequate substitute in whatever recipe calls for buttermilk.

How to Make Cultured Buttermilk

If you aren't in a big hurry or if you're just interested in the process, here's how you can make your own cultured buttermilk from scratch. Unlike the two methods described above, which simply involve adding an acid to milk and letting it curdle, the methods described below will give you true, cultured buttermilk.

Just take note that If you want to make a true cultured buttermilk, which is what you buy at the store, it will take about 24 hours and you will need to start with either an active buttermilk culture or a cup of actual cultured buttermilk. This is great for if you ever have a little bit of leftover buttermilk from a previous recipe that you don't need and you don't want to pour it down the sink. Instead, you can use this method, similarly to how one extends sourdough starter, and create more.

"But if I had buttermilk, I wouldn't need to make my own buttermilk!"

Quite right. We hear you. These two methods are more of a way to reduce food waste and create more buttermilk for a later point in time.

How to Make Homemade Buttermilk From Store-Bought

The easiest way to make your own homemade buttermilk that is cultured is if you already have some cultured buttermilk on hand. Here are the steps:

  1. Start with a 3/4 cup (6 ounces) of cultured buttermilk in a very clean glass quart jar. Add 3 cups of whole milk. It does help if the buttermilk is fresh, because the live buttermilk cultures are more active in fresh buttermilk.
  2. Seal up the jar tightly, give it a good shake to blend everything together, and then let it sit at room temperature, like in your kitchen, for 24 hours. The ideal temperature range is 70 to 77 F. Up on top of your fridge can be a good spot.
  3. After 24 hours, the buttermilk will have thickened to where it will coat the inside of a glass, and it should have a pleasantly tart flavor. Refrigerate to chill or use right away, and store in the refrigerator, where it will keep for several weeks. Repeat the process as often as you like when you get down to the last 6 to 8 ounces of buttermilk.

The key here is the ratio of 4:1. You could use one cup of buttermilk and four cups of whole milk, but that won't fit in a quart jar. Even if all you have is two tablespoons of buttermilk left at the bottom of a carton, you can add four ounces of milk and wind up with five ounces of buttermilk, and you can just keep increasing it from there by repeating the process.

Or you could buy a quart of buttermilk and combine it with a gallon of milk to make five quarts of buttermilk.

The nice thing about this method is that you can keep repeating the process and theoretically never run out of buttermilk again. But you'd need to make sure that the buttermilk you use as your starter is always fresh.

How to Make Homemade Buttermilk From Active Culture

You can purchase active buttermilk cultures, usually in freeze-dried form, and use them to make your own buttermilk, basically by combining the culture with whole milk and letting it sit out for 12 to 24 hours, much like when trying to extend your store-bought buttermilk. As with the above method, you can keep repeating this process, using the last little bit of buttermilk to start the next batch.

Other Common Buttermilk Substitutes

If you don't have any dairy on hand, are allergic to dairy, or are a vegan and choose not to use dairy, but still want a similarly tangy flavor that buttermilk provides and will cause that acidic reaction to occur with baking powder and/or baking soda, don't worry. You can still create your flavorful recipe by substituting out the dairy portion with either coconut milk or soy milk, and adding either a tablespoon of vinegar or lemon juice. Just combine the ingredients as you would have with milk, and allow the mixture to sit for about five minutes before using.

Buttermilk Equivalents and Measures

1 cup buttermilk 242 grams
1 cup buttermilk 8.5 ounces 
1 cup buttermilk 1 cup yogurt
1 cup buttermilk 1 cup milk + 1 tablespoon vinegar or lemon juice
1 cup buttermilk 1 cup milk + 1 3/4 teaspoons cream of tartar
1 cup buttermilk 1 cup water + 4 tablespoons powdered buttermilk
1 cup buttermilk 1/4 cup milk + 3/4 cup yogurt
1 cup buttermilk 1/4 cup milk + 3/4 cup sour cream
1 cup buttermilk 1 cup coconut milk + 1 tablespoon vinegar
1 cup buttermilk 1 cup coconut milk + 1 tablespoon of lemon juice
1 cup buttermilk 1 cup soy milk + 1 tablespoon of vinegar
1 cup buttermilk 1 cup soy milk + 1 tablespoon of lemon juice