Vegan buttermilk substitutes: ratios and which bakes suit
Many baking recipes call for buttermilk because it is acidic, and that acid does real work: it tenderises the crumb and reacts with baking soda to make gas that lifts the bake. You can get the same effect without dairy by adding a little acid to plant milk. This guide gives the amount to use per cup, explains why some plant milks thicken better than others, and shows which bakes suit each version.
What buttermilk does in a recipe
Buttermilk is tangy, slightly thick and acidic. In a recipe it usually does three jobs at once, and a good substitute needs to cover all of them:
- Acid for lift: baking soda needs an acid to react with. When it meets the acid in buttermilk it releases carbon dioxide, which makes batters rise. This is why buttermilk recipes so often use baking soda, sometimes alongside baking powder.
- Tenderness: acid softens gluten strands and proteins, which gives a finer, softer crumb in cakes, biscuits and pancakes.
- Moisture and body: buttermilk is thicker than ordinary milk, so it gives batters a slightly heavier, creamier consistency.
- Flavour: the gentle tang balances sweetness and gives a recognisable taste to soda bread, biscuits and cornbread.
Because the acid is the key ingredient, the substitute only has to be acidic and reasonably thick. It does not need to be cultured or fermented.
The basic method: plant milk plus acid
Put 1 tablespoon (15 ml) of lemon juice or white vinegar in a measuring cup, then add plant milk until you reach the 1 cup (240 ml) line. Stir once and leave it for 5 to 10 minutes. The milk will look slightly curdled and thicker, and that is what you want. Use it as you would use the same amount of buttermilk.
Adding the acid first and topping up with milk means the total volume is correct. If you pour the milk first and add the acid afterwards, you end up with a little more than a cup.
| Buttermilk needed | Lemon juice or white vinegar | Then add plant milk to |
|---|---|---|
| 1/4 cup (60 ml) | 3/4 teaspoon | 1/4 cup (60 ml) |
| 1/2 cup (120 ml) | 1 1/2 teaspoons | 1/2 cup (120 ml) |
| 3/4 cup (180 ml) | 2 1/4 teaspoons | 3/4 cup (180 ml) |
| 1 cup (240 ml) | 1 tablespoon (3 teaspoons) | 1 cup (240 ml) |
| 2 cups (480 ml) | 2 tablespoons | 2 cups (480 ml) |
Apple cider vinegar works in the same amounts. Lemon juice gives the cleanest taste; vinegar is stronger smelling in the bowl but disappears once baked. Bottled and fresh lemon juice are both fine.
Which plant milk to use
All plant milks can be soured, but they do not thicken equally. Curdling depends on protein, so higher-protein milks react more visibly.
| Plant milk | What happens | Worth knowing |
|---|---|---|
| Soy milk | Curdles and thickens the most | Usually the closest match to buttermilk. Choose unsweetened and plain. |
| Oat milk | Thickens a little, curdles lightly | Mild taste; works well in pancakes and muffins. |
| Almond milk | Thickens slightly, may separate into flecks | Thinner result, but fine for batters. Whisk before use. |
| Coconut milk beverage (carton) | Thickens a little | Adds a faint coconut taste. Not the same as canned coconut milk. |
| Rice milk | Little visible change | Thin and low in protein. Acid still works for lift and tenderness. |
Use unsweetened, unflavoured plant milk. Vanilla or sweetened versions add sugar you have not accounted for and can brown the bake faster. If you only have a sweetened milk, cut a little sugar from the recipe.
Another way to make it: plant yogurt
Plain, unsweetened plant yogurt is already acidic and thick. Thin it with plant milk or water until it pours like single cream. A roughly equal mix of yogurt and liquid is a common starting point; adjust until the consistency looks like buttermilk, then measure out the amount the recipe needs.
Yogurt gives the thickest and creamiest result, which suits dense bakes such as muffins, scones and loaf cakes. Because yogurt varies between brands in thickness and sourness, treat the first batch as a trial and add liquid a spoonful at a time.
Which bakes it suits
| Bake | Best choice | Worth knowing |
|---|---|---|
| Pancakes and waffles | Soy or oat milk plus lemon juice | Let the batter rest briefly. Do not overmix, because lumps cook out and a stiff batter makes tough pancakes. |
| Biscuits and scones | Soured soy milk, or thinned yogurt | Keep the fat cold and handle the dough as little as possible. Keep the fat cold; warm hands melt it and the bake turns heavy. |
| Cakes and cupcakes | Soured soy milk or thinned plant yogurt | Keep the baking soda in the recipe. It needs the acid, and the swap supplies it. |
| Muffins and quick breads | Any soured plant milk, or yogurt | Stir only until the flour disappears. |
| Soda bread | Soured soy milk | The acid and the soda do all the raising, so bake straight after mixing. |
| Cornbread | Soured oat or soy milk | Gives the traditional slight tang. |
| Fried-style coatings and marinades | Soured soy milk | Thick enough to cling to vegetables or tofu before breading. |
| Dressings and dips | Thinned plant yogurt | Soured milk is thin; yogurt gives body for ranch-style dressings. |
Common problems and fixes
- The batter tastes sour or vinegary: use lemon juice, check you measured 1 tablespoon and not more, and make sure the bake has finished cooking, since the sharp note fades in the oven.
- The bake did not rise: baking soda that is old loses strength. Also check that you did not leave the batter standing for a long time before baking, because the gas escapes.
- The milk did not curdle: that is normal for rice milk and some brands of almond milk. The acid is still present and still works.
- The crumb is gummy or dense: you probably overmixed. Mix just until combined.
- The bake browns too fast: sweetened milks and extra sugar speed browning. Use unsweetened milk.
- The recipe has no baking soda: acidic milk still tenderises, but some recipes are balanced for plain milk. Use plain plant milk unless the recipe asks for buttermilk or sour milk.
Storage and gluten-free baking
Make soured plant milk when you need it and use it the same day. It is not a cultured product, so it has no advantage from sitting, and plant milks go off like any other fresh product.
Gluten-free bakes also benefit from the acid and moisture, and the same ratios work. Use the flour blend and gum guidance in the gluten-free flour blends guide, and replace the eggs using the egg substitutes guide. If you or someone you bake for needs to avoid certain ingredients, check labels on plant milks and yogurts, since some contain oats, nuts or soy, and ask a doctor or dietitian about allergies and coeliac disease.
What this guide is based on
- The ratio of 1 tablespoon of lemon juice or vinegar per cup of milk, with a 5 to 10 minute rest, is the commonly published rule of thumb for homemade soured milk. It is general cooking knowledge, not a result from our own test baking.
- That acid reacts with baking soda to release gas and tenderises the crumb is general food-science knowledge.
- How each plant milk curdles, and which bakes suit the substitute, is a judgement from how the ingredients generally behave. Brands vary, and none of this comes from our own testing.
- Smaller quantities in the table are simple scaling of the 1 cup ratio. Plant yogurt thinning amounts are a starting point, not an exact figure.
- Allergy, nutrition and coeliac statements are general. Read ingredient labels and ask a doctor or dietitian about your own needs.