Stiff sourdough starter: what it is and when to keep one
A stiff sourdough starter is fed with about half as much water as flour, which gives 50-60% hydration instead of the usual 100%. It behaves like a small piece of dough rather than a batter: firm enough to knead, slower to peak, and noticeably milder and sweeter than a liquid starter. Italian bakers keep one as lievito madre or pasta madre; French bakers call the firm version levain dur.
What the lower hydration changes
Less water means less mobility, and less mobility changes which organisms thrive.
- Milder flavor. Stiff starters favor lactic acid over acetic acid, so the tang is rounder and less sharp. This is the main reason to keep one.
- Slower fermentation. Expect a stiff starter to take roughly 1.5 to 2 times as long to peak as a 100% hydration starter at the same temperature.
- A longer window at peak. It holds near its peak for hours rather than minutes, which is forgiving when your schedule slips.
- More strength. The firmer matrix traps gas better, so a stiff starter often lifts more per gram in the final dough.
- Better keeping. It tolerates a week in the fridge more gracefully, with less hooch and less acid buildup.
The trade is convenience. You cannot stir it with a spoon, it needs squeezing or kneading to incorporate, and it is harder to judge by eye than a bubbly liquid starter.
The ratio
A stiff feed is written the same way as any other, with a smaller water part. Common feeds:
| Feed | Hydration | Peak at 24C (75F) |
|---|---|---|
| 1:2:1 | 50% | 8-10 hours |
| 1:3:1.5 | 50% | 10-14 hours |
| 1:5:3 | 60% | 12-16 hours |
For 20 g of starter at 1:3:1.5, that is 60 g of flour and 30 g of water. Mix it in a bowl, then knead for a minute until it comes together as a smooth, firm ball. It should feel like a tight bread dough, not a paste. The feeding-ratio calculator will do the arithmetic for any keep weight; halve the water it gives you for a 50% stiff feed.
How to convert a liquid starter to stiff
You do not need to start over.
- Take 20 g of your ripe 100% hydration starter.
- Feed it 60 g of flour and 30 g of water. Knead into a firm ball.
- Leave it at room temperature until it has roughly doubled, which will take longer than you are used to.
- Repeat two or three more feeds. By the third the rhythm settles and the smell turns noticeably milder.
Going back the other way is the same process in reverse, and just as quick.
How to tell when a stiff starter is ready
You cannot read a stiff starter by bubbles on the surface, so use these instead:
- Volume. It should roughly double. Marking the jar is more useful here than with a liquid starter.
- The tear. Pull a piece apart. Ready dough is webbed with fine, even holes throughout.
- The dome. A ready stiff starter domes and then cracks across the top as it starts to fall.
- Smell. Yogurt and ripe fruit rather than vinegar.
The float test does not work on a stiff starter. Ignore it.
Baking with one
Use a stiff starter at the same percentage as you would a liquid one, but remember it carries less water into the dough. At 20% starter on 500 g of flour, a 100% hydration starter brings 50 g of water and a 50% stiff one brings 33 g. If you keep your total water the same, your dough will come out roughly 3% drier than the formula says.
Two options: add the missing water back, or run the baker’s percentage calculator with the real starter hydration so the overall figure is honest. The second is more useful once you start comparing bakes.
Also budget more time. A dough leavened with stiff starter typically bulks 20-30% longer than the same formula with a liquid starter. Take the dough temperature and estimate from there with the fermentation calculator.
Is it worth it?
Keep a stiff starter if your bread is consistently sharper than you want and you have already ruled out a long warm bulk and a hungry starter (why is my sourdough too sour). It is also the better choice for enriched doughs like panettone, where sharp acidity fights the butter and sugar.
For everyday country loaves, a well-fed 100% hydration starter on a sensible feeding ratio does the job with less fuss. There is no prize for keeping the harder one.