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Best Buttermilk Substitute in Brownies

5 tested options with exact ratios, science-backed explanations, and tips for success.

Quick Answer

The best substitute for Buttermilk in Brownies is Milk + Lemon Juice or Vinegar because it replicates the acidity and moisture of buttermilk, which helps activate baking soda for proper leavening and maintains the desired tender crumb.

Top 5 Buttermilk Substitutes for Brownies

Substitute Ratio
Milk + Lemon Juice or Vinegar (Best) 1 cup milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)
Plain Kefir 1 cup plain kefir
Milk + Cream of Tartar 1 cup milk + 1 1/2 teaspoons cream of tartar
Soy Milk + Lemon Juice or Vinegar 1 cup soy milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)
Almond Milk + Lemon Juice or Vinegar 1 cup almond milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Detailed Guide: Each Buttermilk Substitute in Brownies

Milk + Lemon Juice or Vinegar (Best Option)

1 cup milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)
Nut-Free Gluten-Free
Quick tip: Closely mimics buttermilk’s acidity and moisture, preserving brownie texture and lift.

Buttermilk’s acidity is crucial in brownies as it reacts with baking soda to produce carbon dioxide, which helps leaven the batter and create a tender crumb. Adding lemon juice or vinegar to milk creates a similar acidic environment that curdles the milk slightly, replicating buttermilk’s chemical properties.

For best results, use whole or 2% milk and allow the acid to sit in the milk for 5-10 minutes before adding to the batter. This ensures proper curdling and acidity. Avoid using skim milk as it lacks fat, which can affect richness.

This substitute maintains the expected rise, moistness, and slight tang of buttermilk brownies, resulting in a texture and flavor very close to the original recipe.

Plain Kefir

1 cup plain kefir
Gluten-Free Nut-Free
Quick tip: Provides acidity and moisture similar to buttermilk, with a mild tang that complements chocolate.

Kefir is a fermented milk product with natural acidity and a consistency close to buttermilk, making it an excellent substitute in brownies. Its lactic acid content activates baking soda, promoting rise and tenderness.

Use plain, unsweetened kefir to avoid altering the sweetness or flavor profile. Because kefir is thinner than yogurt but thicker than milk, it blends well without thickening the batter excessively.

Brownies made with kefir will have a comparable moist crumb and subtle tang, enhancing the chocolate flavor without overpowering it.

Milk + Cream of Tartar

1 cup milk + 1 1/2 teaspoons cream of tartar
Nut-Free Gluten-Free
Quick tip: Adds acidity to milk without changing texture significantly, preserving brownie structure.

Cream of tartar is an acid that can be combined with milk to simulate the acidity of buttermilk. This acid-base reaction is essential for activating baking soda in brownies, ensuring proper leavening and tenderness.

Mix cream of tartar thoroughly into milk before adding to the batter to ensure even acidity. This substitute lacks the slight thickness of buttermilk but maintains moisture well.

Using this substitute results in brownies with good rise and crumb, though the flavor may be slightly less tangy compared to traditional buttermilk.

Soy Milk + Lemon Juice or Vinegar

1 cup soy milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)
Vegan Dairy-Free Nut-Free Gluten-Free
Quick tip: Dairy-free and acidic, suitable for vegan or lactose-intolerant diets but may slightly alter flavor.

Soy milk, when acidified with lemon juice or vinegar, curdles similarly to dairy milk, creating a buttermilk-like substitute. This acidity activates baking soda in brownies, promoting rise and tenderness.

Allow the mixture to sit for 5-10 minutes before use to ensure proper curdling. Soy milk’s protein content supports structure, but the flavor is more neutral and can slightly affect the final taste.

Brownies made with this substitute will have a slightly different flavor profile and may be less rich, but the texture and rise remain comparable to those made with buttermilk.

Almond Milk + Lemon Juice or Vinegar

1 cup almond milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)
Vegan Dairy-Free Nut-Free Gluten-Free
Quick tip: Dairy-free and acidic but lower in protein, which may reduce structure and tenderness slightly.

Almond milk acidified with lemon juice or vinegar can mimic the acidity of buttermilk, helping activate baking soda in brownies. However, almond milk is lower in protein compared to dairy or soy milk, which can affect the batter’s structure and final crumb.

Let the mixture sit for 5-10 minutes to curdle before adding. Because almond milk is thinner and less rich, it may result in slightly less moist and tender brownies.

The final brownies may have a subtle nutty flavor and a slightly different texture, but this substitute works well for dairy-free and vegan diets when buttermilk is unavailable.

Vegan Buttermilk Substitutes for Brownies

Full Vegan guide →
Soy Milk + Lemon Juice or Vinegar
Ratio: 1 cup soy milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Dairy-free and acidic, suitable for vegan or lactose-intolerant diets but may slightly alter flavor.

Almond Milk + Lemon Juice or Vinegar
Ratio: 1 cup almond milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Dairy-free and acidic but lower in protein, which may reduce structure and tenderness slightly.

Gluten-Free Buttermilk Substitutes for Brownies

Full Gluten-Free guide →
Milk + Lemon Juice or Vinegar
Ratio: 1 cup milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Closely mimics buttermilk’s acidity and moisture, preserving brownie texture and lift.

Plain Kefir
Ratio: 1 cup plain kefir

Provides acidity and moisture similar to buttermilk, with a mild tang that complements chocolate.

Milk + Cream of Tartar
Ratio: 1 cup milk + 1 1/2 teaspoons cream of tartar

Adds acidity to milk without changing texture significantly, preserving brownie structure.

Soy Milk + Lemon Juice or Vinegar
Ratio: 1 cup soy milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Dairy-free and acidic, suitable for vegan or lactose-intolerant diets but may slightly alter flavor.

Almond Milk + Lemon Juice or Vinegar
Ratio: 1 cup almond milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Dairy-free and acidic but lower in protein, which may reduce structure and tenderness slightly.

Dairy-Free Buttermilk Substitutes for Brownies

Full Dairy-Free guide →
Soy Milk + Lemon Juice or Vinegar
Ratio: 1 cup soy milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Dairy-free and acidic, suitable for vegan or lactose-intolerant diets but may slightly alter flavor.

Almond Milk + Lemon Juice or Vinegar
Ratio: 1 cup almond milk + 1 tablespoon lemon juice or white vinegar (let sit 5-10 minutes)

Dairy-free and acidic but lower in protein, which may reduce structure and tenderness slightly.

❌ What NOT to Use as a Buttermilk Substitute in Brownies

Plain Yogurt

Plain yogurt can be too thick and tangy, which may alter the texture and flavor of brownies, making them denser and more sour than intended.

Sour Cream

Sour cream is much thicker and richer than buttermilk, potentially resulting in overly dense brownies with a heavier mouthfeel and altered crumb structure.

Regular Milk without Acid

Using regular milk without adding an acid fails to provide the necessary acidity to react with baking soda, leading to less rise and a denser, less tender brownie.

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