The most common reason: your starter is not active enough
A sourdough starter that looks bubbly on top but has not doubled in size within 4 to 8 hours after feeding is not ready to use. Many home bakers feed their starter, wait an hour, and assume it is active. That is too soon. Your starter needs to reach peak activity — the point where it has roughly doubled and shows a dome of bubbles across the surface — before you mix it into dough.
If your starter is sluggish, it is usually because the room is too cold. Sourdough fermentation slows dramatically below 70°F. If your kitchen runs at 65°F or lower, your starter will take 12 to 16 hours to peak instead of 4 to 8. A straightforward fix is to place the jar in a warmer spot: on top of the refrigerator, inside an oven with the light on, or in a proofing box if you have one. Even moving the jar from a cool counter to a sunny windowsill can make a difference.
Another possibility is that your starter is very young — less than two weeks old — or has been neglected for weeks. A neglected starter can revive, but it takes consistent daily feeding for 3 to 5 days before it becomes reliable again. If you feed it once and expect it to work, it will not.
Key Takeaways
- Your starter must double in size and show a dome of bubbles at peak activity before you use it; a bubbly surface alone is not enough.
- Cold temperatures slow fermentation dramatically, so move your dough to a warmer spot if your kitchen is below 70°F.
- Bulk fermentation usually takes 4 to 6 hours at room temperature, but can stretch to 8 to 12 hours in a cool kitchen.
- Overproofing — letting dough rise too long — causes it to collapse rather than spring up in the oven, and is harder to spot than underproofing.
- The poke test (pressing your finger into the dough) tells you whether bulk fermentation is done better than the clock does.
Your dough is fermenting too slowly during bulk rise
Even with an active starter, your dough will not rise on schedule if the room is cold. Bulk fermentation — the first rise, when you let the mixed dough sit in a bowl — typically takes 4 to 6 hours at 75°F. At 68°F, expect 8 to 12 hours. At 60°F, it can take 16 hours or longer, and the dough may not rise noticeably at all.
The fix is the same: move the dough to a warmer place. An oven with the light on, a proofing box, or even a cooler with a jug of warm water inside will speed fermentation. You can also use the cold fermentation method on purpose — letting the dough rise slowly in the refrigerator overnight — which actually improves flavor. But if you are leaving dough at room temperature and expecting it to rise on a normal schedule, cold is working against you.
Do not rely on time alone. Use the poke test instead: gently press your finger into the dough about half an inch deep. If the indent springs back slowly and leaves a slight dimple, bulk fermentation is done. If it springs back when ready, the dough needs more time. If it does not spring back at all, you have likely overproofed.
You are overproofing the dough
Overproofing — letting the dough rise too long — is harder to spot than underproofing, and it ruins the loaf more completely. An overproofed dough looks puffy and soft, but it has run out of strength. When you score it and put it in the oven, it collapses instead of springing up. The crumb ends up dense and gummy rather than open and airy.
This happens most often when you let bulk fermentation go too long, or when you proof the shaped dough (the second rise) for hours at room temperature. A shaped loaf usually needs only 1 to 4 hours at room temperature before baking, depending on how warm the room is and how active your starter is. If you shape the dough in the morning and bake it in the evening, you have almost certainly overproofed.
The poke test works here too. A properly proofed shaped loaf will spring back slowly when you press it. An overproofed one will not spring back at all, or will spring back so slowly that you can watch it happen. If you see that, bake when ready — do not wait longer.
Your starter is too weak or your hydration is too high
If you are using a very small amount of starter — say, 10 grams in a loaf — the dough will rise slowly no matter what. A standard ratio is 20 percent of the dough weight, which means 100 grams of starter for a 500-gram loaf. If you are using less, increase it and see whether the rise speeds up.
High hydration dough — dough with a lot of water — also rises more slowly and can feel like it is not rising at all, because the dough spreads out rather than puffing up. A dough that is 85 percent hydration will look flatter and more slack than a 75 percent hydration dough, even if fermentation is progressing normally. If you are new to sourdough, start with 75 percent hydration and increase it only after you can read the dough reliably.
Check your recipe's hydration percentage. If it is above 80 percent and your dough is not rising visibly, lower it to 75 percent and try again. The dough will be easier to handle and you will see the rise more clearly.
Your oven is not hot enough
Even if your dough rises perfectly, it will not spring up in the oven if the oven is not preheated to at least 450°F. Sourdough needs high heat to set the crust quickly while the interior is still expanding. If your oven runs cool — many home ovens do — the bread will rise slowly in the oven and end up dense.
Preheat your oven for at least 45 minutes, and use an oven thermometer to check the actual temperature. Many ovens are 25 to 50 degrees cooler than the dial says. If your oven is consistently cool, bake at 475°F or 500°F instead of 450°F, or invest in an oven thermometer and adjust the dial to compensate.
You are not scoring the dough
A sourdough loaf needs a score — a deliberate cut made with a sharp blade before baking — to direct where the bread expands. Without a score, the dough will expand unevenly and may not rise much at all. The score tells the dough where to go.
Use a bread lame, a clean razor blade, or a very sharp knife. Make a cut about a quarter-inch deep at a 30 to 45-degree angle across the top of the loaf. One score is enough for a round loaf; longer loaves may need two. Score quickly and confidently — hesitation creates a ragged cut that does not work as well.
Your dough is too dry or too stiff
If your dough is very stiff and hard to stretch, it will not rise well. Sourdough dough should feel slightly tacky and soft, not dry. If you are adding flour by habit or because the dough feels sticky, you may be making it too stiff.
Start with the hydration your recipe calls for and resist the urge to add more flour. If the dough is truly too sticky to handle, wet your hands instead of flouring them. Wet hands let you work with the dough without adding flour. After a few minutes of handling, a slightly sticky dough will feel much easier to work with.
Frequently Asked Questions
How do I know if my starter is ready to use?
Your starter should have roughly doubled in size and show a dome of bubbles across the surface. The top may have a few small bubbles or a slight peak. If it looks bubbly but has not grown noticeably, it is not ready yet. Feed it again and wait another 4 to 8 hours.
Can I use cold fermentation to speed up my baking schedule?
Cold fermentation actually slows the rise — that is the point. You shape the dough, put it in the refrigerator overnight or for up to 48 hours, then bake it straight from cold. This gives you flexibility in when you bake, but the dough takes longer overall. Use it when you want to bake on your schedule, not when you want to speed things up.
What if my dough rises in bulk but collapses when I shape it?
You have likely overproofed during bulk fermentation. The dough has fermented so long that it has lost strength. Next time, use the poke test to end bulk fermentation earlier — aim for a slow spring-back rather than no spring-back. You can also reduce bulk fermentation time by 30 minutes and see whether that helps.
Should I cover my dough while it rises?
Yes. Cover it with a damp towel, plastic wrap, or a shower cap to prevent the surface from drying out. A dry surface will not rise well and may crack unevenly when you score it. Keep the cover on until you are ready to score and bake.
Does the type of flour matter for rise?
Yes. Bread flour (12 to 14 percent protein) rises better and faster than all-purpose flour (10 to 12 percent protein). If you are using all-purpose flour and your dough is rising slowly, switching to bread flour may help. Whole wheat flour also ferments faster than white flour, so a loaf that is 20 percent whole wheat will rise noticeably quicker than one made with only white flour.