Yeast to sourdough converter
Make any yeast recipe with your sourdough starter, or a sourdough recipe with yeast. Enter the flour and water in grams or cups and get the new amounts, with the starter’s own flour and water taken into account.
Milk counts too; it’s mostly water.
Share of the recipe’s flour. 20% suits most breads; less gives a slower rise.
Equal weights of flour and water is 100%, the most common starter.
Your sourdough version
- Starter100% hydration, active and bubbly
- 100g3.5 oz
- Flour
- 450g15.9 oz
- Water
- 300g10.6 oz
Leave out the yeast. Salt and everything else stay the same.
The first rise takes about 5–6 hours at 75°F, instead of 1–2 hours with yeast
For other temperatures, see the bulk fermentation calculator.
How the conversion works
A starter is flour and water with wild yeast in it. Add it to a recipe without changing anything else and the dough ends up wetter and heavier than it should. So the converter takes the starter’s flour and water out of the recipe’s, keeping the dough the same.
A yeast recipe with 500 g of flour and 350 g of water, made with 20% starter at 100% hydration, becomes:
- 100 g starter, which holds 50 g of flour and 50 g of water
- 450 g flour
- 300 g water
- no yeast; the salt and everything else stay the same
New rise times
| At about 75°F (24°C) | With yeast | With 20% starter |
|---|---|---|
| First rise | 1–2 hours | 5–6 hours |
| Second rise after shaping | 45–90 minutes | 2–4 hours, or overnight in the fridge |
Sourdough rises more slowly but tastes deeper and keeps longer. Watch the dough rather than the clock: the first rise is done when it has grown 50–75% and looks airy. The bulk fermentation calculator gives times for your kitchen’s temperature, and the schedule calculator plans the whole bake.
Converting sourdough to yeast
It works the other way too. Leave out the starter, put its flour and water back into the dough, and add instant yeast at about 1% of the flour for a same-day loaf. A sourdough recipe with 450 g flour, 300 g water and 100 g starter becomes 500 g flour, 350 g water and 5 g of instant yeast.
Tips
- Feed your starter so it peaks when you mix. A sluggish starter is the most common reason a conversion disappoints.
- Weigh instead of using cups if you can. A cup of flour can weigh anywhere from 110 to 150 g depending on how you scoop it.
- Need exactly the right amount of starter? The starter feeding calculator works out the feed.
Tools for baking with a starter
Weighing in grams is what makes sourdough repeatable. Links go to Amazon search results, so you can pick any brand.
- Digital kitchen scale
Every number on this site is in grams. Any scale that reads to 1 g, holds at least 5 kg and has a tare button will do.
- Straight-sided starter jar
A clear jar with straight sides and a rubber band around it shows at a glance when your starter has doubled.
- Instant-read thermometer
Dough temperature sets the pace of bulk fermentation. Around 75–78 °F (24–26 °C) keeps the timings in most recipes on track.
Questions bakers ask
How much sourdough starter replaces a packet of yeast?
There's no exact swap, because starter is also flour and water. Use starter that weighs about 20% of the recipe's flour: for a recipe with 4 cups (480 g) of flour, that's 96 g, about ½ cup of active starter. Then take its flour and water out of the recipe, which is what the converter does.
Can I convert any yeast recipe to sourdough?
Most breads, rolls and pizza doughs convert well. Rich doughs with lots of butter, sugar or eggs, like brioche and cinnamon rolls, rise much more slowly with starter alone; many bakers keep a pinch of yeast in those. Quick breads made with baking powder or soda aren't yeast recipes and don't need converting.
Do I change the salt or other ingredients?
No. Salt, sugar, butter, eggs and everything else stay the same. Only the flour, the water and the leavening change.
Can I use sourdough discard instead of active starter?
Discard adds flavor but usually can't raise a loaf on its own. Keep the yeast, add the discard, and take the discard's flour and water out of the recipe: with a 100% hydration discard, half its weight is flour and half is water.
Why is my converted dough rising so slowly?
Sourdough is slower than yeast: a first rise of 4–8 hours is normal, compared with 1–2 hours for yeast. Make sure the starter is at its peak when you mix, keep the dough around 75°F (24°C), and judge the rise by how much the dough has grown, not by the recipe's original times.