Can I use plain milk as a buttermilk substitute?

Not on its own. Plain milk is approximately pH 6.5 — not acidic enough to react with baking soda. If a recipe calls for buttermilk AND baking soda, using plain milk will produce dense, flat results. Always add 1 tbsp of acid (lemon juice or vinegar) per cup of milk if substituting.

Does the milk need to be whole milk?

Any fat content works, but whole milk gives the best texture match. Skim milk substitutes will produce slightly drier baked goods.

How long does the milk+acid mixture need to sit?

Five minutes is enough to see the curdling that indicates the acid has activated. You can use it longer (up to 30 min) but no advantage past 5 min.

Buttermilk substitutes

Buttermilk's job in a recipe is two-fold — it adds acidity (which reacts with baking soda for lift) and contributes a tangy, creamy flavor. Most "buttermilk substitutes" you'll see only cover one of these. The ranking below sorts options by how well they handle both jobs in the most common use cases.

Rank	Substitute	Ratio (replaces 1 cup Buttermilk)	Notes
#1	Milk + lemon juice	1 cup milk + 1 tbsp lemon juice (let stand 5 min)	Best all-purpose substitute. Matches both acidity and consistency closely. Whole milk preferred but any milk works.
#2	Milk + white vinegar	1 cup milk + 1 tbsp distilled white vinegar	Identical results to the lemon version. Use whichever you have on hand. Don't use balsamic or apple cider vinegar — flavor is too strong.
#3	Plain yogurt (thinned)	3/4 cup plain yogurt + 1/4 cup milk or water	Excellent flavor match. Slightly thicker — thin with milk before adding to batters. Greek yogurt also works but needs more thinning.
#4	Sour cream (thinned)	3/4 cup sour cream + 1/4 cup milk	Rich and tangy. Particularly good in biscuits and pancakes.
#5	Kefir	1 cup kefir, used 1:1	A near-direct swap. Kefir is naturally acidic and slightly thinner than buttermilk. Use as-is.
#6	Cream of tartar + milk	1 cup milk + 1 3/4 tsp cream of tartar	Works for the chemistry but flavor is one-note. Use only when you have no other acid available.

Substituting for a specific recipe?

The best substitute depends on what you're making. Pick your use case:

Buttermilk in pancakes → Buttermilk in marinades →

Following a specific diet?

These substitutes are filtered for dietary restrictions:

dairy free Buttermilk substitutes → vegan Buttermilk substitutes →

When to be careful

Avoid water-based substitutions in baked goods where you need both acidity AND creaminess (biscuits, scones, soda bread). The thinner liquids change the dough hydration enough to noticeably affect texture.

Why these substitutes work

Buttermilk is acidic (pH around 4.5) thanks to lactic acid from bacterial fermentation. When you add it to a batter with baking soda, the acid reacts with the soda to release carbon dioxide, which is what makes pancakes rise and biscuits flake. Any substitute needs to bring acidity comparable to lactic acid. The lemon-juice and vinegar tricks work because they curdle the milk on contact, mimicking the acid level. Yogurt and sour cream already contain lactic acid from their own fermentation, which is why they're closer flavor matches.

Buttermilk substitutes work best when you match the original recipe’s purpose: acidity for baking soda reactions, creaminess for tender crumb, and tang for flavor. The ranking above is sorted with that priority order in mind. For more specific guidance, see the use-case pages linked below.

Frequently asked questions

Can I use plain milk as a buttermilk substitute?: Not on its own. Plain milk is approximately pH 6.5 — not acidic enough to react with baking soda. If a recipe calls for buttermilk AND baking soda, using plain milk will produce dense, flat results. Always add 1 tbsp of acid (lemon juice or vinegar) per cup of milk if substituting.
Does the milk need to be whole milk?: Any fat content works, but whole milk gives the best texture match. Skim milk substitutes will produce slightly drier baked goods.
How long does the milk+acid mixture need to sit?: Five minutes is enough to see the curdling that indicates the acid has activated. You can use it longer (up to 30 min) but no advantage past 5 min.