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This homemade buttermilk is unlike any other you’ll find online. I teamed up with my husband (who has a Ph.D. in Chemistry) to figure out how to make buttermilk that tastes as close to the store-bought versions. Now I’m sharing the results and the best way to make buttermilk at home.

A spoon full of buttermilk being held above a mason jar full of buttermilk with fresh whole and sliced lemons all around
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Homemade Buttermilk

I always test and perfect my recipes before sharing, and this homemade buttermilk is no different. I noticed that almost every tutorial I found online follows the same ratio: one cup of buttermilk and one tablespoon of lemon juice or white vinegar. It made me wonder: where did this ratio come from, and is it really the best?

two mason jars with lids on labeled DIY buttermilk with tape with whole fresh lemons and a bottle of distilled vinegar in the background

How We Used Science to Make the Best Homemade Buttermilk

That’s where the experimenting started. Since my husband has a PhD in Chemistry, I brought him in to do a little science experiment and help me perfect it.

The purpose of the experiment was to determine exactly how much acidic ingredients (lemon juice or vinegar) we really should be adding to the milk. To do so, we first tested the pH of store-bought traditional buttermilk. 

Let’s pause for a moment because what is pH? I know this is a food blog, not a science blog, but cooking and baking has a lot of science in it! pH is a quantitative measure of the acidity or basicity of liquid solutions. The range goes from 0 – 14, with 7 being neutral.

Store-bought buttermilk has a pH range of 4.4-4.8. To make the best homemade buttermilk substitute, we needed to find a DIY alternative that yields a similar pH.

You can test the pH of any liquid solution using a pH test strip, which is what we did. The substance in the paper test strip causes the paper to show a different color at different acidities. 

You can watch a video of the whole tutorial in my Instagram story highlights here.

pH testing strips on a counter top beside yellow sticky notes and class containers of buttermilk, with the strips labeled: "1 tbsp white vinegar", "2 tbsp white vinegar", "buttermilk - control", "2 tbsp lemon juice", "1 tbsp lemon juice"

The pH levels we tested:

Store-bought buttermilk: This is our baseline. We are looking for a result similar in color to this test strip when we test our own recipes.

1 cup Whole milk + 1 Tbsp fresh lemon juice: (Indicated by the red arrow on the right side of the photo.) You can see that the bottom square is darker than the store-bought control. This means the pH is less acidic. 

1 cup Whole milk + 2 Tbsp fresh lemon juice: You can see from the photo that the color indicator is very similar to the store-bought control, meaning the pH is very similar. 

1 cup Whole milk + 1 Tbsp distilled vinegar: (Indicated by the red arrow on the left side of the photo.) You can see that the bottom square is darker than the store-bought control. This means the pH is less acidic. 

1 cup Whole milk + 2 Tbsp distilled vinegar: You can see from the photo that the color indicator is very similar to the store-bought control, meaning the pH is very similar. 

A countertop with the setup for a buttermilk experiment on it, with 5 clear glass containers with different buttermilk mixtures in them, sitting on yellow sticky note labels with pH test strips, and a carton of store-bought buttermilk, two whole lemons and a bottle of distilled vinegar sitting beside them

Conclusion

What we found from all of this testing was that using 2 tablespoons of acid (lemon juice or vinegar) with 1 cup of whole milk yielded a pH that was closest to store-bought buttermilk. This means the ratio of 1 cup:1 tablespoon provided in most of the tutorials you find online is not the best at-home solution if you really want to mimic the taste, texture, and chemical reaction of store-bought buttermilk.

Next, was the baking test!

I baked 2 batches of my lemon muffins. One using the DIY buttermilk method of 2 tablespoons of vinegar mixed with 1 cup of whole milk and the other using store bought buttermilk.

The result? Both batches looked and tasted identical! There was no discernible difference between them!

a mason jar full of buttermilk with a lid on, labeled with tape that says "DIY Buttermilk: vinegar + whole milk", with a measuring spoon beside it an a bottle of vinegar in the background

Why do we use buttermilk in baking? 

Buttermilk is really popular in baking; in fact, it’s in almost all of my muffin recipes. There are several reasons why it is popular in baking, including: 

  • Tenderizing: The acidity helps tenderize gluten in baked goods, resulting in a softer texture. 
  • Leavening: It contains lactic acid, which reacts with leaveners to produce carbon dioxide bubbles, helping the baked goods rise. To achieve the amount of rise you want without sacrificing the tangy taste (which might happen if you use too much baking soda), you’ll need to add baking powder as well. Using its delayed double-action, you can make the end result even lighter.
  • Flavor: It adds a tangy flavor to baked goods, which can enhance the overall taste and balance sweetness in recipes like cakes and scones.
  • Moisture: It adds moisture to baked goods, keeping them from drying out and resulting in a more moist and tender crumb.

Overall, buttermilk contributes to the texture, flavor, and moisture of baked goods, making them more delicious and enjoyable.

a mason jar full of buttermilk with a strip of tape on it labeled "DIY Buttermilk: lemon + whole milk", with fresh lemons all around

What is Buttermilk?

Buttermilk is a dairy beverage with a tangy flavor and creamy texture, and it’s often used in cooking and baking to add moisture and acidity to dishes. It is typically made by fermenting low-fat milk with lactic acid bacteria, giving it its characteristic taste and texture.

a clear class jar of buttermilk with a white tablespoon and a small clear glass jar of vinegar and a bottle of vinegar in the background

Why you’ll love this Buttermilk Recipe

You no longer need to make a trip to the grocery store for buttermilk. There are so many things to love about this buttermilk substitute recipe, including:

  • Just 2 simple ingredients
  • Perfect ratio of milk to acid
  • Classic buttermilk taste with a pleasant tang
  • Easy recipe with only 2 minutes of prep
  • Perfect for baking, pancake recipes, and more!
a mason jar full of buttermilk surrounded by fresh whole and sliced lemons, a white tablespoon measurer and a small clear glass jar of lemon juice

DIY Buttermilk Recipe Ingredients

This homemade buttermilk substitute only has two basic ingredients that you likely already have on hand:

  • Whole milk or 2% milk
  • Fresh lemon juice OR distilled white vinegar 

How to make Buttermilk

Making an easy buttermilk substitute at home only takes 2 minutes of actual prep, and then it’s ready in under 15 minutes! To make this recipe:

For every 1 cup of whole milk, stir in 2 tablespoons of lemon juice or white vinegar. Let the mixture stand for 10 minutes. You can scale the recipe up or down depending on how much you need. Use as directed in your recipe. 

How to Store Homemade Buttermilk

The best way to store homemade buttermilk is in a clean, glass airtight container. Use it within one week, and give the sealed container a little shake before use if it’s been sitting for a while.

How long does Buttermilk last?

This buttermilk is best when used within one week.

Can you freeze Buttermilk?

Yes, this recipe freezes well. Store it in an airtight container or freezer-safe bag for up to 3 months. You can also freeze it in tablespoon portions in an ice cube tray (sealed inside a freezer safe bag).

How to tell if Buttermilk is bad?

You will notice signs of spoilage if this recipe has gone bad, such as a foul odor, unusual texture, or discoloration.

a mason jar with buttermilk from a clear class measuring cup being poured into the jar and fresh whole and sliced lemons surrounding the jar

Homemade Buttermilk Recipe FAQs

Is it better to use vinegar or lemon juice when making buttermilk?

Based on our test results from the pH testing, it doesn’t matter if you use vinegar or lemon juice, as long as you use 2 tablespoons total.

Is homemade buttermilk the same as buttermilk?

Homemade buttermilk and store-bought buttermilk can be similar but are not identical. The homemade version is made by combining milk with an acid, such as lemon juice or vinegar, and allowing it to sit and curdle. While homemade can mimic store-bought, it may not have the same consistency or exact flavor profile because store-bought buttermilk undergoes controlled fermentation.

Why does homemade buttermilk taste different?

The homemade version tends to be a bit thinner than storebought, but this recipe comes very close in taste because we use the correct ratio of acid to milk, as proven in our pH testing.

Can you drink buttermilk?

Yes, this recipe is safe to drink.

Recipes that use Buttermilk

two mason jars with lids on labeled DIY buttermilk with tape with whole fresh lemons and a bottle of distilled vinegar in the background
5 from 4 ratings

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DIY Buttermilk Recipe

By: Beth
Prep Time: 2 minutes
Cook Time: 10 minutes
Servings: 1 cup
This homemade buttermilk is unlike any other you'll find online. I teamed up with my husband (who has a Ph.D. in Chemistry) to figure out how to make buttermilk that tastes as close to the store-bought versions we love as possible. Now I'm sharing the results and the best way to make buttermilk at home.

Ingredients

  • 1 cup Whole milk or 2% milk, 237 mL / 8 oz
  • 2 Tbsp fresh lemon juice OR distilled white vinegar, 30 mL

Instructions 

  • For every 1 cup of whole milk, stir in 2 tablespoons of lemon juice or white vinegar. Let the mixture stand for 10 minutes. You can scale the recipe up or down depending on how much you need. Use as directed in your recipe.

Notes

Not suitable for raw applications, such as buttermilk dressing
Scaling Cup Measurements
  • For 1/2 cup buttermilk:
    1/2 cup whole milk + 1 tablespoon fresh lemon juice or white vinegar
  • For 3/4 cup buttermilk:
    3/4 cup whole milk + 1 ½ tablespoons fresh lemon juice or white vinegar
  • For 1 cup buttermilk:
    1 cup whole milk +2 tablespoons fresh lemon juice or white vinegar
  • For 1 & 1/2 cups buttermilk:
    1 & 1/2 cups whole milk + 3 tablespoons fresh lemon juice or white vinegar
  • For 2 cups buttermilk:
    2 cups whole milk + 4 tablespoons fresh lemon juice or white vinegar
Scaling Metric Measurements
  • For 1/2 cup buttermilk:
    118 mL / 4 oz whole milk + 15 mL fresh lemon juice or white vinegar
  • For 3/4 cup buttermilk:
    177 mL / 6 oz whole milk + 22 mL fresh lemon juice or white vinegar
  • For 1 cup buttermilk:
    237 mL / 8 oz whole milk + 30 mL fresh lemon juice or white vinegar
  • For 1 & 1/2 cups buttermilk:
    355 mL / 12 oz whole milk + 44 mL fresh lemon juice or white vinegar
  • For 2 cups buttermilk:
    473 mL / 16 oz whole milk + 59 mL fresh lemon juice or white vinegar

Nutrition

Serving: 1cup | Calories: 146kcal | Carbohydrates: 11g | Protein: 8g | Fat: 8g | Saturated Fat: 5g | Polyunsaturated Fat: 0.3g | Monounsaturated Fat: 2g | Cholesterol: 29mg | Sodium: 93mg | Potassium: 366mg | Sugar: 12g | Vitamin A: 395IU | Calcium: 300mg
Like this recipe? Rate and comment below!

About Beth

I believe that everyone should have a go-to dessert to bring to parties! With hundreds of recipes, I'll help you find yours!

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10 Comments

  1. Thanks so much for posting this. I love to bake and I always keep buttermilk on hand. Sometimes when using a lot I might come up a little short and run out. I have used those recipes online but they just don’t taste the same. I will try this and thanks again.

  2. I often use buttermilk to make Scandinavian puddings. These are generally made with heavy cream (whipped) as well. The texture of store-bought is thicker than whole milk. How will your DIY recipe compare? Will these puddings set or do I need to add gelatin?

    1. Hi Ellen! Without personally testing it, I can’t give an accurate answer. I don’t have any experience in using buttermilk or DIY buttermilk in pudding.

    1. Hi Karen! The DIY version isn’t stable like the store bought versions, so I recommend that you make it and use it within the hour.

  3. Hello!
    Would you specify what percentage vinegar is used in your recipe?
    I have sometimes 5%,sometimes less.
    Thank you!

  4. 5 stars
    This is so interesting! Thank you and your husband for taking the time to figure out the best diy buttermilk!

    Some other time, when you’re bored (ha, ha!), I’d be interested to know if this same ratio works well in dairy-free “milks”.

  5. 5 stars
    Sounds good. Will this come out as good with soy or other plant-based milk replacements?

    Thank You!

    1. I haven’t personally tried it, but other readers are reported using dairy free milk and that it works!