Buttermilk Substitute Calculator

No buttermilk in the fridge? Mix your own from milk and a splash of acid. Tell the calculator how much buttermilk you need and it works out the exact milk and lemon juice (or white vinegar) to combine, in any unit. Reach for it when:

  • Buttermilk isn't on the shopping list: a carton goes off before most home bakers finish it. Mix the amount you need.
  • Soda bread, scones, or pancakes: recipes that lean on baking soda need an acid to lift them; this substitute supplies it.
  • Lemon juice vs white vinegar: lemon juice suits sweet bakes; white vinegar is more neutral once baked and works better in savoury recipes.
  • Any quantity, any unit: scale up for a big batch of pancakes or down to a few tablespoons for a single bake.

Calculate Substitute

Per 1 cup of buttermilk:

  • 1 tablespoon lemon juice or white vinegar
  • Milk to fill the cup (about 1 cup minus 1 tablespoon)

You'll need:

Milk234.38
Lemon Juice1.04

Tip: stir the lemon juice into the milk, then let it sit at room temperature for about 5 minutes until it thickens and curdles slightly. The acid sours the milk so it behaves like buttermilk in the recipe.

Why This Substitute Works

Buttermilk brings two things to a recipe: a tangy flavour and gentle acidity that reacts with baking soda to help cakes, pancakes, and quick breads rise. Adding a small amount of lemon juice or white vinegar to ordinary milk gives you the same acidity, so the leavening chemistry still works. After a few minutes the milk curdles slightly, mimicking buttermilk's thicker texture.

Lemon Juice or White Vinegar?

For this substitute, both work in the same 1 tablespoon per cup ratio. The acid amount is small, so lemon juice and white vinegar give the same lift. (When swapping one acid for the other in a recipe directly, white vinegar is sharper and you typically use about half as much.) Lemon juice adds a faint citrus note that suits sweet bakes, scones, and pancakes. White vinegar is more neutral once baked and is a better choice for savoury recipes like soda bread or fried chicken marinades.

Frequently Asked Questions

What can I use instead of buttermilk?
Stir 1 tablespoon of lemon juice or white vinegar into milk and top up to the buttermilk amount your recipe needs. Let it sit for about 5 minutes until it curdles slightly. The acid mimics buttermilk's tang and reacts with baking soda the same way. Open buttermilk converter
How do I make buttermilk from milk and lemon juice?
Use 1 tablespoon of lemon juice for every 1 cup of buttermilk you need, then add milk to fill. Stir, rest for 5 minutes, and the milk will curdle slightly. The calculator above gives the exact amount of each in any unit, so you can scale it up or down to fit the recipe. Open lemon juice converter
Can I use white vinegar instead of buttermilk?
Yes. White vinegar works the same way as lemon juice. Use 1 tablespoon per cup of buttermilk and top up with milk. The flavour is more neutral than lemon juice once baked, which suits savoury recipes like soda bread, fried chicken marinades, and cornbread. Open white vinegar converter
How long does the buttermilk substitute need to sit?
Five minutes at room temperature is enough. The acid lowers the pH of the milk, causing it to curdle slightly and giving the same tang and reactivity buttermilk brings to a recipe. Longer doesn't help; the milk won't fully thicken like real buttermilk. Stir before adding to the batter. Open buttermilk converter

Other Ingredients

If you need help with any other ingredients click below: