Buttermilk is a slightly acidic, tangy dairy product used in pancakes, waffles, cakes, quick breads, and fried chicken marinades. Its acidity tenderises gluten, reacts with baking soda to create lift, and adds a mild tang. But most recipes only call for a small amount, making it impractical to buy a full carton.
The Classic Buttermilk Substitute
For 1 cup (240ml) of buttermilk:
- Measure 1 tablespoon of white vinegar or lemon juice into a liquid measuring cup.
- Add milk (whole milk works best) to reach the 1-cup line.
- Stir briefly and let stand for 5 minutes.
- The milk will curdle slightly — this is exactly what you want.
Use this in place of buttermilk in a 1:1 ratio.
Why It Works
Regular milk is neutral (pH ~6.5). Adding an acid (vinegar or lemon juice, both pH ~2–3) lowers the pH to around 4.5–5, similar to real buttermilk. This acidic environment reacts with baking soda, producing carbon dioxide bubbles that leaven your recipe. The acid also partially denatures the milk proteins, creating the slightly curdled texture of buttermilk.
Other Buttermilk Substitutes
| Substitute | Ratio |
|---|---|
| Plain yogurt | 1:1 (thin with a splash of milk if needed) |
| Sour cream | 1:1 (thin with milk to pouring consistency) |
| Kefir | 1:1 |
| Milk + lemon juice | 1 cup milk + 1 tbsp lemon juice |
| Milk + white vinegar | 1 cup milk + 1 tbsp vinegar |
Does It Taste Different?
Homemade buttermilk substitute is very close to the real thing in baked goods. The slight tang of real buttermilk is mostly undetectable once baked — the main functional role (acidity) is what matters.