There's nothing quite as disheartening as checking on your sourdough starter only to find it sitting there, flat and lifeless, refusing to rise. You've been feeding it diligently, following all the advice, and yet... nothing. Trust me, every sourdough baker has been there, and I'm here to tell you that a sluggish starter is almost always fixable.
After years of troubleshooting starters for myself and countless other bakers, I've identified the seven most common culprits behind a starter that won't rise. Let's dive into each one so you can get your starter bubbling and active again.
1. Your Water Temperature Is Off
This is the single most common mistake I see, and it's an easy fix. Your starter is home to wild yeast and beneficial bacteria, and these microorganisms are extremely sensitive to temperature.
If you're using water that's too cold—anything below 21°C (70°F)—you're essentially putting your starter into hibernation mode. The fermentation process slows to a crawl, and you won't see much rise at all. On the flip side, water above 38°C (100°F) can actually kill the yeast and bacteria you've worked so hard to cultivate.
The sweet spot: Use water between 24-27°C (75-80°F) for feeding. This temperature range encourages active fermentation without shocking your microbes. I keep a kitchen thermometer handy specifically for this purpose—it's worth the small investment.
2. You're Keeping It Too Cold (Or Too Hot)
Water temperature matters, but so does the ambient temperature where your starter lives. Your starter needs a consistent, warm environment to thrive.
If your kitchen is consistently below 18°C (65°F), your starter will be sluggish or completely inactive. I've seen bakers struggle for weeks, only to discover their starter was sitting next to a drafty window or in a basement pantry.
The solution: Find a spot that stays between 21-24°C (70-75°F). Some of my favorite warm spots include on top of the refrigerator, inside a turned-off oven with the light on, or near (not on!) a heating vent. In winter, I sometimes use a proofing box or even wrap my starter jar in a towel and place it near a warm appliance.
Just remember: consistency is key. Wild temperature swings confuse your starter's ecosystem.
3. Your Feeding Ratio Is Wrong
This one trips up a lot of bakers. If you're feeding your starter too much flour and water relative to the amount of starter you're keeping, you're diluting the yeast population. There simply aren't enough active microorganisms to ferment all that fresh flour in a reasonable timeframe.
Conversely, if you're not feeding enough, your starter will exhaust its food supply, become overly acidic, and the yeast will struggle to stay active.
For a sluggish starter, try a feeding ratio of 1:1:1 (equal parts starter, flour, and water by weight). This gives the existing yeast population plenty to work with without overwhelming them. Once your starter becomes more active, you can adjust to 1:2:2 or even 1:5:5 if you want to extend the time between feedings.
4. You're Not Feeding It Often Enough
Here's a hard truth: if your starter is active and healthy, it needs regular feedings. A starter that's left unfed for too long will consume all available sugars, the pH will drop dramatically, and the environment becomes inhospitable for yeast.
In this overly acidic state, you'll see liquid (often called "hooch") pooling on top, and the yeast activity will plummet. Your starter might smell like nail polish remover or extremely sour vinegar—not the pleasant tangy aroma of a healthy culture.
The fix: At room temperature, most starters need feeding every 12-24 hours when active. If you can't commit to that schedule, store your starter in the refrigerator where it only needs weekly feedings. Just remember to bring it back to room temperature and give it 2-3 feedings before you plan to bake.
5. Your Flour Isn't Providing Enough Fuel
Not all flours are created equal when it comes to feeding a sourdough starter. Highly refined white flour, while it works, contains fewer nutrients and minerals than whole grain options. If your starter seems perpetually weak, your flour choice might be the culprit.
Whole grain flours like whole wheat or rye contain more of the bran and germ, which are rich in minerals, enzymes, and nutrients that wild yeast and bacteria love. They also have higher populations of wild microorganisms on the grain itself.
My recommendation: If your starter is struggling, try switching to a blend of 50% all-purpose flour and 50% whole wheat or rye flour. Many bakers find that even a small percentage of whole grain flour (as little as 10-20%) can dramatically improve starter activity. Once it's thriving, you can experiment with different ratios.
Also check that your flour is fresh and hasn't been sitting in your pantry for months—stale flour produces sluggish starters.
6. You're Using Chlorinated Water
Chlorine is added to municipal water supplies to kill bacteria and other microorganisms. While this keeps our drinking water safe, it can seriously inhibit the growth of the beneficial bacteria and wild yeast in your starter.
If you're using straight tap water, chlorine might be preventing your starter from developing a robust microbial community. Some regions have higher chlorine levels than others, so this issue varies by location.
The easy solution: Let your tap water sit out in an open container for 24 hours before using it. The chlorine will evaporate naturally. Alternatively, use filtered water or bottled spring water (avoid distilled water, which lacks beneficial minerals).
I've seen starters transform within 2-3 feedings simply by switching from chlorinated tap water to filtered water. It's worth testing if nothing else has worked.
7. Your Starter Is Too Young
I know, I know—patience isn't easy, especially when you're excited to bake your first loaf. But the truth is that a brand new starter takes time to develop a balanced, active microbial ecosystem.
During the first week or two of creating a starter from scratch, it's completely normal to see an initial burst of activity followed by a period where nothing seems to happen. This is when the early-colonizing bacteria give way to the true sourdough microorganisms—the lactobacilli and wild yeasts that will eventually dominate your mature starter.
The timeline: A truly active, reliable starter typically takes 7-14 days to develop, sometimes longer depending on conditions. If your starter is less than two weeks old and not rising much, just keep feeding it consistently. Don't give up! The microbes are building their community, and you'll see results if you stay the course.
Troubleshooting: Bringing Your Starter Back to Life
If your starter has been struggling, here's my proven revival protocol:
Day 1-3: Feed at a 1:1:1 ratio twice daily using lukewarm water (24-27°C / 75-80°F) and a blend of flour that includes some whole grain. Keep it in a warm spot around 24°C (75°F).
Day 4-7: You should start seeing increased bubbling and rise. When your starter doubles in size within 4-8 hours of feeding, it's on the right track.
Signs of success: Look for a dome-shaped rise, lots of bubbles throughout (not just on top), a pleasant sour-yeasty aroma, and a consistency that's thick and elastic when stirred.
You've Got This
A sluggish starter can feel like a baking crisis, but now you have a clear checklist of potential issues to investigate. In my experience, it's usually a combination of temperature and feeding ratio that's causing the problem. Make these adjustments, be consistent, and give your starter a little time to respond.
Remember: sourdough starters are remarkably resilient. Even if yours has been neglected or struggling, it can almost always be brought back to vigorous life with the right care. The wild yeast and bacteria want to thrive—your job is simply to create the right environment for them.
Keep feeding, stay patient, and soon you'll have that beautiful, bubbly starter rising predictably and ready to bake with. Happy baking!