Why Is My Sourdough Starter Not Rising Common Mistakes And How To Fix Them

Sourdough baking is as much a science as it is an art. At the heart of every successful loaf lies a healthy, active sourdough starter—your living culture of wild yeast and bacteria. But what happens when your starter refuses to rise? You feed it religiously, keep it at room temperature, use filtered water, yet it remains flat and lifeless. This is one of the most common frustrations among home bakers, both new and experienced.

The good news: in nearly every case, a sluggish or inactive starter can be revived. The issue usually stems from preventable mistakes in feeding, environment, or ingredient quality. Understanding the root causes allows you to troubleshoot effectively and restore your starter’s vitality.

Understanding How Sourdough Starters Work

A sourdough starter is a symbiotic culture of wild yeast and lactic acid bacteria cultivated from flour and water. When fed regularly, these microorganisms ferment the starches in flour, producing carbon dioxide gas and organic acids. The gas creates bubbles that cause the starter—and eventually your dough—to rise, while the acids contribute to flavor and shelf life.

For this fermentation process to work efficiently, certain conditions must be met:

• Consistent food supply (fresh flour)
• Optimal temperature (ideally 70–78°F / 21–26°C)
• Balanced hydration (typically 100% hydration = equal parts water and flour by weight)
• Clean tools and containers to avoid contamination

If any of these factors are off, your starter may fail to peak or collapse shortly after rising. Let’s examine the most frequent errors and how to correct them.

Common Mistakes That Prevent Rising

1. Inconsistent or Incorrect Feeding Schedule

One of the top reasons starters fail to rise is irregular feeding. Wild yeast need fresh nutrients every 12–24 hours when kept at room temperature. Skipping feeds or delaying them causes the population to starve, weaken, and eventually die off.

Another issue is improper ratios. Some bakers use too much old starter relative to fresh flour and water, overwhelming the microbes with acidity. A standard feeding ratio is 1:1:1 (starter:water:flour by weight), but if your starter is struggling, switching to 1:2:2 or even 1:5:5 can help dilute acidity and give microbes a better chance to multiply.

Tip: If your starter hasn’t risen within 8 hours of feeding, try refreshing it with a lower inoculation ratio (e.g., 1 part starter to 5 parts flour and water).

2. Using Cold Water or Flour Straight from the Fridge

Temperature plays a critical role in microbial activity. Cold water or chilled flour can significantly slow down fermentation—even if your kitchen feels warm. Always use water at room temperature (around 70–75°F) and store flour in a cupboard, not the refrigerator, unless necessary for long-term preservation.

3. Poor Flour Quality or Type

Not all flours are equally effective for maintaining a starter. Highly processed white flours lack the nutrients wild microbes thrive on. While all-purpose flour works, many bakers find that whole grain flours like rye or whole wheat provide more robust microbial growth due to their higher mineral and enzyme content.

Using only bleached flour or low-protein cake flour can starve your starter over time. Similarly, expired or insect-infested flour introduces contaminants and lacks nutritional value.

“Rye flour is nature’s turbocharger for sourdough starters. Its high amylase and mineral content gives microbes a rapid energy boost.” — Dr. Karl Brenner, Microbial Fermentation Researcher, University of Copenhagen

4. Unfavorable Ambient Temperature

Most sourdough cultures perform best between 70°F and 78°F (21–26°C). Below this range, fermentation slows dramatically; above 85°F (29°C), harmful bacteria may outcompete beneficial ones.

Kitchens near drafty windows, air conditioning units, or exterior walls often have microclimates too cold for consistent rising. Conversely, placing a starter atop a warm fridge or near a stove can create excessive heat.

5. Chlorinated Tap Water

Municipal tap water often contains chlorine or chloramine, which are added to kill pathogens but also harm beneficial microbes in your starter. While small amounts may not kill a mature starter outright, they can inhibit growth and delay activity—especially in new or delicate cultures.

Switching to filtered, spring, or boiled-and-cooled tap water often results in noticeable improvement within one or two feedings.

Step-by-Step Guide to Reviving a Dormant Starter

If your starter has been neglected for days or weeks, don’t discard it immediately. Most dormant starters can be brought back with consistent care. Follow this timeline:

1. Day 1: Discard all but 20g of starter. Feed with 100g whole rye flour and 100g lukewarm filtered water. Mix well, cover loosely, and place in a warm spot (75°F ideal).
2. Day 2: Check for bubbles and aroma. Even slight signs mean life remains. Repeat feeding with same ratio. If no activity, proceed anyway—microbes may still be recovering.
3. Day 3: Switch to 1:5:5 feeding (20g starter, 100g flour, 100g water). Use whole wheat or rye flour again. Bubbles should appear, along with a tangy, yogurt-like smell.
4. Day 4: Begin twice-daily feedings (every 12 hours). Use unbleached all-purpose or bread flour if desired. Watch for doubling in volume within 6–8 hours.
5. Day 5–6: Once doubling consistently, switch to maintenance mode (1:1:1 ratio). Your starter is ready for baking.

This method works even for starters stored in the fridge for months. Patience and consistency are key.

Do’s and Don’ts: Quick Reference Table

Do’s	Don’ts
Use filtered or spring water	Use chlorinated tap water
Feed at consistent intervals (12–24 hrs)	Feed sporadically or skip days
Store in a warm, draft-free area	Keep near AC vents or cold windows
Use whole grain flour during revival	Rely solely on bleached all-purpose flour
Clean jar weekly to prevent mold buildup	Leave starter in a dirty container long-term
Discard before feeding to maintain balance	Add new flour without discarding first

Real Example: Sarah’s Comeback Starter

Sarah, a home baker in Portland, Oregon, left her sourdough starter unattended for three weeks while traveling. She returned to find a layer of gray liquid (hooch) on top and a sharp acetone smell—classic signs of starvation. Many would have discarded it, but she decided to try reviving it.

She poured off the hooch, saved 20g of the thick sludge at the bottom, and began feeding it twice daily with rye flour and filtered water. By day three, bubbles appeared. On day five, it doubled within seven hours. Within a week, she baked a beautifully airy boule with a crisp crust and complex tang.

Her mistake? Going too long without feeding. Her fix? Diligent feeding with nutrient-rich flour. Now, she keeps a backup portion frozen and sets phone reminders for feedings when she plans to travel.

Tip: Pouring off hooch (the dark liquid) is safe and often necessary. It indicates your starter needs food, not that it’s dead.

How to Test Starter Readiness

Before baking, always confirm your starter is active. The “float test” is popular but unreliable. A better method is the **rise-and-fall observation**:

• Feed your starter with a 1:1:1 ratio (by weight).
• Mark the level on the jar with a rubber band or tape.
• Observe every hour. A healthy starter should double in size within 4–8 hours, depending on temperature.
• It should have a pleasant, fruity-sour aroma—not harsh or rotten.
• After peaking, it will slowly deflate. Use it at its peak or just before collapse for best leavening power.

If it doesn’t double, repeat the feeding with a lower inoculation ratio until it does.

Frequently Asked Questions

Can I use tap water if I boil it first?

Yes. Boiling tap water for 5–10 minutes removes chlorine, though not chloramine. For chloramine, use a carbon filter or leave water uncovered for 24 hours to allow dissipation.

Why does my starter rise slightly then fall quickly?

This usually means the starter peaked and collapsed before you noticed. It’s a sign of activity but inconsistent timing. Try feeding earlier or using a warmer location to speed up fermentation so you can catch the peak.

Is it safe to bake with a starter that smells like vinegar or nail polish remover?

Strong acidic or solvent-like odors indicate over-fermentation or starvation. While not dangerous, such a starter lacks strength. Refresh it 1–2 times before baking to restore balance.

Checklist: Troubleshooting Your Sourdough Starter

Use this checklist to diagnose and fix issues:

• ✅ Is the starter being fed every 12–24 hours at room temperature?
• ✅ Am I discarding part of the starter before each feed?
• ✅ Am I using non-chlorinated water?
• ✅ Is the ambient temperature between 70–78°F?
• ✅ Am I using whole grain or unbleached flour?
• ✅ Has the container been cleaned recently?
• ✅ Did I check for mold or pink/orange hues? (If yes, discard immediately.)
• ✅ Have I given it at least 5–7 days of consistent feeding if reviving?

Run through this list whenever your starter underperforms. Often, correcting just one factor leads to immediate improvement.

Final Thoughts: Patience and Observation Are Key

Your sourdough starter is a living ecosystem, sensitive to changes in routine, environment, and ingredients. When it fails to rise, view it not as a failure, but as feedback. Each adjustment you make deepens your understanding of fermentation and strengthens your baking skills.

Don’t rush the process. Even the most experienced bakers face setbacks. What separates success from frustration is persistence, attention to detail, and a willingness to learn from each batch.

💬 Have a starter rescue story or tip? Share your experience in the comments below—your insight could help someone save their first (or fiftieth) starter.