Proof & LoafSourdough Starter Not Rising? 8 Common Causes and Fixes
A starter that won’t rise is the most common sourdough frustration, especially once the weather turns cold. The fix is usually simple and free.
How we chose: we compared manufacturer specs, independent test-kitchen results and owner feedback. We haven’t hands-on tested these products ourselves. Our methodology.
Quick answer
- Most often it’s temperature. Below about 70°F (21°C) a starter can take twice as long to peak. A warmer spot fixes more starters than anything else.
- New starter (under two weeks)? A burst of bubbles around days 2–3 followed by a quiet spell is normal. Keep feeding on schedule.
- Check flour, water and ratio next: unbleached flour, a little whole grain, and a feeding ratio that matches how warm your kitchen is.
- A cheap instant-read thermometer tells you whether the kitchen is the problem before you buy anything bigger.
First: is your starter new or established?
The fix depends on the starter’s age. A new starter (roughly the first one to two weeks) often bubbles dramatically early on, then goes flat for a few days. That early rise is usually caused by bacteria that die back as the mix gets more acidic, not by the yeast you want. The quiet spell is a normal stage, so the right move is patience and steady feeding, not starting over.
An established starter that used to double and suddenly doesn’t has usually had something change: the season, the flour, the feeding schedule, or a long stretch in the fridge.
8 common causes and what to try
1. Your kitchen is too cold
Fermentation slows a lot in a cool room, which is why starters seem to “die” every autumn. Many bakers aim for roughly 75–80°F (24–27°C). Free ways to get there: the oven with only the light on (check with a thermometer, since some get too hot, and leave a note so nobody preheats it), the top of the fridge, near but not on a warm appliance, or a small cooler with a jar of warm water inside. Feeding with lukewarm water helps too.
2. It’s peaking while you’re not looking
In a warm kitchen, a starter can rise and fall back within a few hours. If you only check it in the morning, it may already have peaked and collapsed overnight. Look for streaks on the jar wall above the current level. A rubber band or marker line at the level right after feeding makes this obvious, which is one reason straight-sided glass jars are popular (see our starter jar guide).
3. The feeding ratio doesn’t match the temperature
A big feed like 1:5:5 (starter:flour:water by weight) takes much longer to peak than 1:1:1. In a cold kitchen, a smaller ratio peaks sooner; in a warm one, a bigger ratio stops it from running out of food. If you’re unsure what the numbers mean, our beginner guide covers the basics, and a kitchen scale makes ratios easy to repeat.
4. Measuring by volume
A cup of flour can vary a lot depending on how it’s scooped, so a starter fed by cups gets a slightly different thickness every day. Weighing in grams keeps it consistent. Hydration matters too: a thinner, wetter starter tends to rise less visibly than a thick paste, even when it’s just as active.
5. The flour
Bleached flour and some very refined flours give the microbes less to work with. Many bakers revive a sluggish starter by swapping some of the white flour for whole wheat or rye, often 10–25% of the feed. Unbleached all-purpose or bread flour is a good everyday base.
6. Chlorinated water
This is less common than people think, but if you’ve tried everything else, use filtered water or tap water left out uncovered for a few hours. Note that chloramine, which some cities use, doesn’t evaporate the same way; filtered or bottled water sidesteps that.
7. It just came out of the fridge
A starter stored cold for a week or more often needs two or three feeds at room temperature before it rises reliably again. Gray liquid on top (hooch) just means it’s hungry: pour it off or stir it in, then feed.
8. It’s actually fine
Not every healthy starter doubles. Some flours and thinner starters rise less but still raise bread well. Signs it’s ready to bake with: it rises predictably after feeding, has bubbles throughout, smells pleasantly sour or yeasty, and has a domed or just-flattening top. The float test (a spoonful floating in water) is popular but unreliable, especially for wet or whole-grain starters, so trust the rise and bubbles more.
When it is worth buying something
Most sluggish starters need warmth and consistency, not gear. If your kitchen stays cold all winter, though, these are the tools bakers most often use.
ThermoPro TP03 Instant Read Thermometer
A simple instant-read thermometer to check your water, your dough and your “warm spot” (like the oven with the light on) so you know whether temperature really is the problem.
- Inexpensive
- Useful for dough and bread temperature too
- Not a room monitor; take spot readings
Brod & Taylor Sourdough Home
A small box that holds a starter jar at a set temperature, and can also cool it to slow it down. It’s a convenience, not a requirement; our proofer and warmer guide compares it with free options.
- Holds a set temperature
- Can also cool
- Only fits a jar, not dough
- Free warm spots often work just as well
Weck 743 Mold Jar (3/4 L, box of 6)
Straight glass sides make it easy to see how far your starter rose and when it peaked, and spare jars make switching to a clean one simple.
- Easy to read the rise
- Loose glass lid lets gas escape
- Six jars is more than one starter needs
Escali Primo Digital Food Scale
A simple scale with 1 g steps and tare, so every feed uses the same ratio. Compare others in our scale guide.
- Simple and reliable
- Compact
- Wide bowls can hide the display
A simple reset plan
- Discard all but about 25–50 g of starter.
- Feed it 1:1:1 by weight with unbleached flour (swap in some whole wheat or rye) and lukewarm water.
- Keep it somewhere around 75–80°F and mark the level.
- Repeat every 12–24 hours, checking a few times a day for the peak.
- Once it rises predictably within roughly 4–8 hours, go back to your normal ratio.
Most bakers see a difference within a few days. Throw a starter out only if it has pink or orange streaks or fuzzy mold; that usually means starting over is the safe choice.
Want to try baking before your starter is perfect? Our no-Dutch-oven baking guide shows you don’t need special gear to start.
Frequently asked questions
Why is my sourdough starter not rising?
The most common cause is a cold kitchen. Other causes are a missed peak, a feeding ratio that is too large for the temperature, measuring by volume, or bleached flour.
Why did my new starter stop bubbling after a few days?
A big rise around days 2 or 3 followed by a quiet spell is normal for a new starter. Keep feeding on schedule; it usually becomes active again within a week or so.
Does a sourdough starter have to double?
No. Many healthy starters rise less, especially thin or whole-grain ones. A predictable rise, bubbles throughout and a pleasant sour smell matter more than doubling exactly.
What temperature does a sourdough starter need?
Many bakers aim for about 75 to 80°F (24 to 27°C). Starters still work in a cooler kitchen, just more slowly.
Should I throw out a starter that won't rise?
Usually not. Try a few warm, consistent 1:1:1 feeds first. Discard it only if you see pink or orange streaks or fuzzy mold.
Related guides
Is a Sourdough Proofing Box Worth It? Proofers and Starter Warmers Compared
Free ways to keep dough and starter warm, and when a Brod & Taylor proofer or Sourdough Home is worth it.
StarterThe Best Sourdough Starter Jars (and What Makes One Good)
Straight sides, wide mouth, loose lid: how to choose a jar for your starter, and the jars bakers rely on.
Beginner kitSourdough Starter Kit for Beginners: The Tools You Actually Need
The short list of tools that make your first sourdough easier, and the things you can skip.
ScalesThe Best Kitchen Scale for Sourdough Bread Baking
Why grams matter, what capacity you need, and four scales that work well for sourdough.
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