Sourdough Discard substitute

Best substitute

Equal weights flour and water plus an acid

For 1 cup (240 g) discard: 120 g flour plus 120 g water plus 1 tablespoon lemon juice or vinegar

Best for sourdough discard crackers

Different taste

The direct arithmetic swap, and the one to reach for in crackers, biscuits, banana bread or anything where discard is quietly acting as part of the batter. Most starters are kept at one hundred percent hydration, meaning equal flour and water by weight, so splitting a cup of discard back into its two halves is exact.

Other sourdough discard substitutes

Ranked, with the exact amount to use

2Buttermilk plus flour
Close match
For 1 cup (240 g) discard: 120 g (about ½ cup) buttermilk plus 120 g (a scant cup) flour
The best-tasting substitute by a clear margin, and the right choice for pancakes, waffles and biscuits.
What changes
Buttermilk is soured by lactic acid bacteria, the same family that sours a starter, so the tang has the same rounded dairy quality instead of a vinegar edge.
Best for
sourdough discard pancakes, waffles, biscuits, scones, quick breads
Slightly richer and it browns noticeably more in the pan because of the milk sugars, which in a waffle is an improvement rather than a compromise. Whisk the flour into the buttermilk first and let it sit ten minutes so it hydrates, otherwise the batter can taste faintly raw. Plain kefir works identically and is a touch tangier.
3Plain yogurt thinned with water, plus flour
Close match
For 1 cup (240 g) discard: 80 g yogurt plus 40 g water plus 120 g flour
Effectively the same idea as the buttermilk route using something more likely to be in the fridge.
What changes
Thin the yogurt to pouring consistency first so it disperses instead of sitting in lumps, then whisk in the flour.
Best for
pancakes, waffles, muffins, flatbread, quick breads
Thicker and tangier than buttermilk, so the batter needs a little extra liquid and the sourness comes through more strongly, which is arguably closer to a well-aged discard. Greek yogurt is much thicker and needs more water. The extra fat makes cakes and muffins more tender and slightly heavier.
4Kombucha or beer as the liquid, plus flour
Different taste
For 1 cup (240 g) discard: 120 g kombucha or beer plus 120 g flour
A genuinely clever route for savoury applications, because both bring yeasty aromatics as well as acidity, which is the part vinegar cannot supply.
What changes
Kombucha is sour and faintly funky, beer is yeasty and malty.
Best for
crackers, flatbread, savoury waffles, pizza dough, batter for frying
Kombucha's flavour depends heavily on which one you bought, so a ginger or fruit-flavoured bottle will show up in the finished cracker. Beer pushes things malty and bready rather than sour, so add a teaspoon of vinegar alongside if the recipe relies on acid for baking soda. Neither works in a sweet cake.
5Make a fake discard overnight
Close match
Use Equal weights flour and water plus 1 tablespoon yogurt for every cup, left out 24 hours
If you have a day rather than an hour, mix flour and water in equal weights with a spoonful of live yogurt, cover loosely and leave it at room temperature for about 24 hours.
What changes
It will smell tangy and slightly boozy and behave very much like the real thing.
Best for
any discard recipe, crackers, pancakes, when the sour flavour is the point
This is the closest you get without a starter, because you are actually fermenting rather than imitating. It will not be as complex as a mature starter that has been going for a year, and it has no reliable leavening power, which is fine because discard does not either. Use it within a day or two and keep it in the fridge after the first day.
6The honest answer: a discard recipe without a starter is a different recipe
Different taste
If a recipe is named for the discard, the discard is the flavour, and a flour-water-vinegar batter will produce something good that does not taste sour in the way you were hoping.
What changes
Accept that and lean the other direction: add a little more salt, more butter or more cheese so the thing has a reason to exist.
Best for
setting expectations honestly
Worth knowing which way round the question runs. Discard is a poor leavener, so if you were planning to use discard in place of yeast in a loaf, that is a different and harder problem, and the answer is to feed the starter and wait rather than to substitute. In cracker and pancake recipes, discard is flavour and batter, not lift.

What is Sourdough Discard?

Sourdough Discard is the unfed starter you take out and set aside before refreshing the rest, a slack batter of roughly equal weights of flour and water that has already fermented and turned tangy but is no longer lively enough to leaven a loaf on its own, so in a recipe it is acting as flour, as liquid and as sourness all at the same time.

Cooking tips

Weigh rather than measure if you can. A cup of discard is a slack sticky batter that packs unpredictably, so scooping it gives wildly different amounts, and the whole substitution rests on splitting its weight in half. If a recipe gives grams of discard, halve that number for flour and halve it again for liquid.
Check the hydration of the starter the recipe assumes. Most home bakers keep starter at one hundred percent hydration, equal flour and water, so the fifty-fifty split works. A stiff starter fed at fifty percent hydration is two parts flour to one part water, so adjust accordingly or the batter will come out slack.
The acid is not optional when baking soda is present. Discard recipes lean on discard's sourness to react with the soda and produce lift, so if you replace discard with plain flour and water and no acid, the soda has nothing to react with and you get a flat pancake with a distinct soapy aftertaste. One tablespoon of lemon juice or vinegar per cup of discard replaced is the fix.
Older discard from the back of the fridge is much more sour than fresh discard, and its liquid layer, sometimes called hooch, is the sourest part of all. If a recipe was written for week-old discard and you are imitating it, be generous with the acid.
Discard also brings enzyme activity that softens the flour and makes doughs more extensible, which is why discard crackers roll out so thinly. A flour-and-water substitute will feel springier and fight you a little; let the dough rest twenty minutes before rolling and it relaxes.

Frequently asked questions

Can I just leave the sourdough discard out?

No, not without replacing the volume, because in most discard recipes it is a substantial share of the total flour and liquid. Leaving out a cup of discard from a pancake batter removes about half a cup of flour and half a cup of liquid, and what is left will be far too dry and will not pour. Split it back into flour and liquid as above, add an acid, and the recipe works.

What is the difference between sourdough discard and sourdough starter?

Physically nothing; they are the same mixture at different points in its cycle. A starter that has just been fed and has risen is active and can leaven bread. Discard is the portion you remove before feeding, so it is hungry and deflated and has spent most of its raising power, which is exactly why discard recipes pair it with baking powder or baking soda rather than relying on it for lift. Unfed starter and discard mean the same thing.

Can I use active starter instead of discard?

Yes, and it is a straight swap by weight. Active fed starter is less sour than discard because the acids have been diluted by the recent feeding, so pancakes and crackers made with it taste milder. It will also contribute a little extra rise, which in a cracker is harmless and in a pancake just makes it slightly puffier. Nothing goes wrong.

Does discard still work if it has been in the fridge for a month?

For flavour, yes, and it will be very sour. Stir the dark liquid on top back in, or pour it off if you want it less sharp. It should smell tangy, yeasty and vinegary, perhaps of acetone. What it should not have is fuzzy mould, pink or orange streaks, or any smell of rot; any of those and the whole jar goes out. Do not use very old discard in a recipe that has no other leavener.

What is the best substitute for discard in crackers specifically?

Equal weights flour and water with a tablespoon of vinegar, plus a twenty-minute rest before rolling. Crackers are the application where the flour-water arithmetic matters most and the flavour matters least, because the salt, olive oil and whatever herbs or cheese you add do most of the talking. Kombucha in place of the water is a small upgrade if you happen to have a plain bottle open.

Related substitutes

More baking substitutes

Sourdough Discard substitute

Other sourdough discard substitutes

2Buttermilk plus flour

3Plain yogurt thinned with water, plus flour

4Kombucha or beer as the liquid, plus flour

5Make a fake discard overnight

6The honest answer: a discard recipe without a starter is a different recipe