Can I Replace Buttermilk With Whey? A Comprehensive Guide

November 25, 2025 •

4 min read

According to food scientists, whey and buttermilk share similar properties that allow for effective substitution in many recipes, particularly due to their comparable pH levels. So, can I replace buttermilk with whey? Yes, but success depends on understanding the differences in their thickness and fat content to make the right adjustments.

Quick Summary

This guide explains the key differences between whey and buttermilk and provides practical tips for a successful substitution in baking and cooking. Learn how to adjust liquid quantities, manage texture, and achieve the desired leavening and flavor profile in your recipes. Proper storage and understanding different types of whey are also covered.

Key Points

Acidity is Shared: Both whey and buttermilk are acidic, which allows whey to effectively trigger baking soda and provide the necessary lift in baked goods.
Adjust for Consistency: Whey is much thinner than buttermilk, so you need to use less (around 20-25% less) to achieve the correct batter or dough consistency.
Monitor for Faster Browning: The lactose in whey accelerates the Maillard reaction, causing baked goods to brown more quickly; lower your oven temperature to prevent this.
Add Fat for Richness: To compensate for whey's lower fat content, consider adding a small amount of extra fat like melted butter or oil for a richer texture.
Great for Pancakes and Biscuits: Whey is a perfect buttermilk replacement for pancakes, waffles, biscuits, and scones, where a fluffy, tender crumb is desired.
Freeze for Future Use: Unused whey can be frozen in ice cube trays for long-term storage and easily thawed for later use in baking or smoothies.

Understanding the Differences Between Buttermilk and Whey

Before attempting a swap, it's crucial to understand the distinct properties of buttermilk and whey. Buttermilk, specifically cultured buttermilk, is known for its creamy, viscous texture and tangy flavor, which is a result of bacteria fermenting milk sugars. It also contains milk solids and fat globules that contribute to a rich taste and texture. Whey, the liquid leftover from straining yogurt or making cheese, is much thinner and clearer. While it also has a tangy, acidic character, it lacks the fat and milk solids found in cultured buttermilk. This fundamental difference in consistency is the main factor you must address for a successful substitution.

The Role of Acidity and Leavening

Both buttermilk and whey are acidic, which is their key function in many baking recipes. The acid reacts with baking soda to create carbon dioxide bubbles, which acts as a leavening agent to make baked goods light and fluffy. This chemical reaction is what allows whey to effectively activate baking soda in the same way buttermilk does. However, because whey is thinner, it's important to adjust the quantity to prevent a runny batter or dough. King Arthur Baking, for example, suggests reducing the amount of whey by about 20–25% when substituting for buttermilk in many baking recipes.

Flavor and Browning Profile

While both offer a pleasant tang, the flavor profile can differ slightly. Acid whey, from yogurt or cottage cheese, is often tangier than sweet whey from cheese-making. Additionally, whey contains lactose, a reducing sugar that promotes the Maillard reaction, leading to a more pronounced browning in baked goods. Some bakers suggest lowering the oven temperature slightly to prevent over-browning. True buttermilk, containing more milk fat globule membranes (MFGM), offers a richer, more complex flavor and superior emulsification properties. The result with whey may be slightly different in both flavor and color, but it can still produce delicious results.

Practical Steps for Substituting Whey for Buttermilk

Here is a step-by-step guide to help you make a successful swap in your next recipe.

Adjust Liquid Volume: The most important adjustment is the quantity. Since whey is thinner, start by using less liquid than the recipe calls for. For every 1 cup of buttermilk, use about 3/4 to 4/5 of a cup of whey. You can always add a little more if your batter seems too thick, but you can't take it out once it's in.
Consider Adding Fat: If the recipe relies on buttermilk for richness, such as in biscuits or cakes, consider adding a small amount of extra fat. A teaspoon of melted butter or oil can help compensate for the lower fat content of whey.
Monitor Baking Time and Temperature: The lactose in whey can cause your baked goods to brown faster. Keep a close eye on your item and consider reducing the oven temperature by about 25°F (around 10–15°C) to prevent burning.
Trial and Error is Key: Every recipe and every batch of homemade whey is slightly different. The whey from Greek yogurt is a concentrated, acid whey, while the whey from a softer cheese might be sweeter. Experiment with small batches to see how the substitution affects your specific recipe.

Recipe Applications

Whey can be a fantastic substitute in a wide range of recipes where buttermilk's acidity is the primary requirement. Some successful applications include:

Pancakes and Waffles: Whey provides the perfect acidity for a fluffy texture.
Biscuits and Scones: The acidic nature of whey reacts with baking soda for a great rise, yielding a light and flaky result.
Sourdough Bread: Adding whey can enhance the tanginess of a sourdough starter and is a great way to use up excess.
Marinades: The lactic acid in whey is an excellent meat tenderizer, similar to buttermilk.

Whey vs. Buttermilk: A Comparison Table


Feature	Buttermilk	Whey	Effect on Substitution
Consistency	Thicker, more viscous	Thinner, watery	Reduce whey quantity to prevent a runny batter.
Fat Content	Higher, contains milk fat globules	Very low, mostly water	May need to add a bit of fat for richer results.
Acidity	Tangy, but with more complex flavor notes	Tangy, depends on source (acid vs. sweet)	Both effectively activate baking soda for leavening.
Flavor	Richer, more creamy profile	Can be sharper (acid whey) or milder (sweet whey)	Flavor may be slightly less complex but still tangy and pleasant.
Browning	Standard browning effect	Promotes faster, deeper browning (Maillard reaction)	Monitor oven temperature to prevent over-browning.

Storing and Handling Whey

To maximize the utility of your homemade whey, proper storage is essential. Store whey in an airtight container in the refrigerator and use it within one to two weeks. For longer storage, whey can be frozen in ice cube trays and transferred to a freezer bag once solid. Frozen whey can be used in smoothies, soups, or thawed for baking. This prevents waste and ensures you always have a tangy, acidic liquid on hand for your recipes.

Conclusion: Making the Most of Your Whey

Ultimately, the question of "can I replace buttermilk with whey?" has a positive answer, but with the caveat that success requires a few mindful adjustments. While whey lacks the thickness and fat of traditional buttermilk, its comparable acidity makes it a perfectly viable and nutritious substitute for activating leavening agents and adding a pleasant tang to recipes. By reducing the liquid volume, monitoring for faster browning, and being prepared for a slightly different richness, you can successfully leverage leftover whey from cheese or yogurt making. This not only makes for a resourceful kitchen practice but also a delightful culinary experiment, proving that one person's byproduct can truly be another's baking gold.

Frequently Asked Questions

You can replace buttermilk with whey in most recipes, particularly baked goods like pancakes, biscuits, and cakes where its acidity is the primary function. However, adjustments for liquid volume and richness are typically necessary.

A good starting point is to use 3/4 to 4/5 of a cup of whey for every 1 cup of buttermilk called for in a recipe. It is best to start with less and add more if needed, as whey is thinner.

Yes, it can. Whey adds a tangy, slightly different flavor than buttermilk. The type of whey (e.g., from yogurt vs. hard cheese) will also influence the final taste, from more acidic to slightly sweeter.

Since whey is lower in fat than cultured buttermilk, it is often a good idea to add a small amount of fat, like a teaspoon of melted butter or oil, to recipes where richness is important.

Whey contains lactose, a sugar that contributes to the Maillard reaction. This chemical process causes the baked goods to brown more quickly. To avoid over-browning, you can reduce the oven temperature.

Whey can be stored in an airtight container in the refrigerator for one to two weeks. For longer preservation, freeze the whey in ice cube trays and then transfer the cubes to a freezer bag.

Yes, but be aware of the different types. Acid whey from Greek yogurt is tangy and works well in baking. Sweet whey from hard cheese is milder. Experimentation is recommended for the best results in specific recipes.