Stir 1 tablespoon lemon juice or white vinegar into enough milk to make 1 cup, then let it stand 5 to 10 minutes. For better flavor, mix plain Greek yogurt and milk 1:2.
Ratios from university extension services and King Arthur Baking. Checked .
Buttermilk substitutes, best first
- For 1 cup buttermilk1 Tbsp lemon juice or white vinegar + milk to make 1 cup; let stand 5-10 minutesBest for: pancakes, cakes, quick breads
Nebraska/Utah State say 5 minutes, King Arthur 10-15. Rises well but tastes less tangy in biscuits (King Arthur).
- For 1 cup buttermilk1/3 cup Greek yogurt + 2/3 cup low-fat or skim milk (1:2)Best for: biscuits, pancakes
King Arthur's top performer: runner-up in biscuits, tied with buttermilk in pancakes.
- For 1 cup buttermilk1 cup plain yogurtBest for: baking
Utah State, NMSU, Mississippi State; thin with a little milk if very thick.
- For 1 cup buttermilk1 cup milk + 1 3/4 tsp cream of tartarBest for: baking when you have no lemon or vinegar
Utah State, NMSU, King Arthur.
- For 1 cup buttermilkSour cream thinned with milk or water to heavy-cream consistencyBest for: baking in a pinch
King Arthur; no exact ratio given.
What not to use
Plain milk with no added acid: in King Arthur's tests it gave flat-tasting biscuits, lower pancakes and a darker, denser cake, since there's no acid for the baking soda.
Why the swaps work
Buttermilk's acidity reacts with baking soda to make carbon dioxide and tenderizes gluten; any swap needs similar acidity.
Questions people ask
How long should homemade buttermilk sit?
Extension charts say about 5 minutes; King Arthur lets it stand 10-15 minutes.
Can I use regular milk instead of buttermilk?
Not on its own—add lemon juice, vinegar or cream of tartar so the baking soda has acid to react with.
Sources
- Buttermilk substitute (King Arthur Baking)
- Ingredient Substitutions (Nebraska Extension, UNL)
- Ingredient Substitution, FN 255 (Utah State University Extension)
- In a Pinch: Ingredient Substitution, Guide E-131 (New Mexico State University Extension)
- Ingredient Substitutions and Equivalents, P1690 (Mississippi State University Extension)