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If you’re wringing your hands, wondering “Why is my sourdough starter not rising?” You’re in the right place. Here we’ll talk about eight common problems that stunt sourdough starter growth and how to (easily!) fix them.

If you’ve found yourself here in my little corner of the internet, I’ll assume you’re having trouble with your sourdough starter.

I’ll assume that you’ve followed our How to Make a Sourdough Starter Guide to a T, gave it all of your attention and brain cells, only for it to sit as a sad little lump in your mason jar.

I’ll also assume that you’ve given it your final thread of patience and are now screaming, “Why is my sourdough starter not rising??” at the family pet who just ran to hide under the bed.

Deep breath, my friend. You are in the right place.

I’ve been where you are, frustrated. Pacing the kitchen floor. Wringing your apron, wondering “Why me? Why is everything better at sourdough than me?“

I thought my first few attempts at a sourdough starter were a gigantic failure.

Turns out, there were a few simple things that needed adjusting, and then, voila, bubbly, acting sourdough starter that passed the float test and gave me bread. Now here I am, running a support group for sourdough bakers.

Let me be the first to reassure you that everything is going to be ok.

If your sourdough starter is not rising, the most common causes are temperature, feeding ratio, flour type, water quality, or simply that it’s still too young (baby steps, my friends). Starters need a warm environment (ideally 75–80°F), consistent feedings, and unbleached flour to build strength. In many cases, a sluggish starter just needs a few small adjustments and a little time to become active and double reliably.

Pull up a chair and let me walk you through it.

How to Diagnose the Problem when asking “Why is my Sourdough Starter Not Rising?”

If you’re wondering, “Why is my sourdough starter not rising?” you already know the problem. What we’re here to figure out is the root cause. The key is to look at what it’s doing, not just what it’s not doing.

Before you do anything, take a deep breath and check:

• Is it bubbling at all?
• Does it smell sour, neutral, or unpleasant?
• Is your kitchen warm or cool?
• How old is your starter?

These clues will help you pinpoint the issue quickly. Let’s walk through each potential problem, step by step

1. Your Kitchen Is Too Cold

One of the most common reasons a sourdough starter is not rising is the temperature of its environment.

Wild yeast and beneficial bacteria thrive in warmth. When your kitchen drops below 70°F (21°C), fermentation slows dramatically.

Signs this is your issue:

• Small bubbles but very little rise
• Starter takes more than 12 hours to show activity
• Thick texture but minimal expansion

Ideal temperature: 75–80°F (24–27°C)

If you’re like me, your house doesn’t get to 75 degrees unless the AC is out. Don’t worry, you don’t have to live in the Sahara to have a healthy sourdough starter.

Here’s how to fix it:

• Place your starter on top of the refrigerator if it radiates warmth (mine does not, so this has never worked for me).
• Put it inside the oven with just the light on and a sign on the oven door to remind you not to turn it on with your starter inside.
• Use a proofing box or heating pad set to low (my absolute favorite method).
• Move it to the warmest room in your house (think closet, bathroom, mantle).

If temperature is your problem, you should see improvement within 24–48 hours after warming it up. Hooray!

2. Your Starter Is Too Young

If you just started your sourdough starter within the last 5–10 days, it may not be strong enough yet to rise consistently, and that’s ok. In fact, that’s perfectly normal

Many beginners panic around day 3 or 4 because the starter rises dramatically, then falls flat and goes maddeningly silent.

“What the heck?” you might say, “Why is my sourdough starter not rising?”

Patience grasshopper. This early rise is often caused by temporary bacterial activity (which is good!)— not stable wild yeast. A lull afterward is completely normal.

What to do:

• Keep feeding consistently according to your Sourdough Starter Guide
• Don’t skip days
• Stay patient (my nemesis!)

Most starters stabilize and begin doubling reliably around days 7–14. Hang in there. Your consistency will be rewarded (with bread).

3. Your Feeding Ratio Is Off

Another major reason your sourdough starter is not rising is an imbalance in feeding. In case you skipped this explanation in the sourdough starter guide, feeding is just giving your starter flour and water so it can grow and thrive. Established starters are pretty resilient, but they can still be temperamental if you mess with their feedings (aren’t we all?)

Too Much Water (Overly Thin Starter)

If your starter looks runny and spreads flat immediately after feeding, it may be too hydrated to trap gas.

Even if bubbles are forming, the structure isn’t strong enough to hold them.

How to fix it:
Feed using a 1:1:1 ratio by weight (starter : flour : water) using a scale or measuring cup. If it’s very thin, slightly reduce the water until it holds a soft, thick consistency.

Overfeeding a Weak Starter

If you use too much flour and water compared to the amount of starter, you dilute the yeast population.

The microbes need time to multiply. Overfeeding can reset progress repeatedly.

How to fix it:
Try smaller, consistent feedings (for example, 1 tablespoon starter to 2 tablespoons flour and 2 tablespoons water every 12 hours).

Underfeeding

If your starter smells sharply sour or develops liquid (hooch) on top, it may be starving.

Fix:
Feed every 12 hours in a warm environment until it becomes active and predictable.

4. You’re Using the Wrong Flour

Sourdough starters aren’t overly fussy, but they can be picky about their flours. Bleached flour or flour with additives (like basic fortified flours) can slow fermentation. For everyday feedings, look for a good quality organic, unbleached flour.

If it’s overly sluggish and needs a little extra TLC, whole wheat and rye flours contain more nutrients and natural yeast, making them excellent for strengthening a weak starter.

If your sourdough starter is not rising:

• Switch to unbleached all-purpose
• Or try feeding with whole wheat or rye for a few days

Many starters respond quickly to this change and you should be on your way to making bread in no time.

5. Your Water Contains Chlorine

Chlorine is the silent killer of sourdough starter (and possibly our brain cells. A conversation for another time.) Tap water treated with chlorine or chloramine can inhibit yeast growth without you even knowing it.

Signs this might be the problem:

• No visible mold
• No terrible smell
• But consistently weak activity

How to fix it:

• Use filtered water
• Use bottled water temporarily
• Let tap water sit overnight (this removes chlorine, but not chloramine)

If chlorinated water is the issue, improvement is usually noticeable within a few feedings, and you can move forward using the correct water.

6. It’s Bubbling But Not Rising

A sourdough starter with bubbles but no rise is maddening. There are enough signs of life to tell you you’re on the right track, but not enough to give you bread. So, in this case, why is my sourdough starter not rising?

If your starter has bubbles but does not double in size, it means fermentation is happening, but the structure is too weak to trap gas.

Possible causes:

• Too much water
• Low-protein flour
• Not enough gluten development

How to fix it:

• Thicken the starter slightly by increasing the flour in your feeding
• Switch to stronger flour (more protein)
• Keep it warmer (heating pad, top of the fridge, warm closet)

Once the structure of your starter improves, rising should follow.

7. It Rises and Then Collapses Quickly

It’s common to think of your sourdough starter like an ocean tide, rising and falling. You want to bake when it’s at high tide. But what if you keep missing high tide?

If your starter doubles but falls within a few hours, it may not be weak; it may be peaking and then over-fermenting.

This doesn’t mean your sourdough starter isn’t rising. It means you’re missing its peak.

How to fix it:

• Feed and mark the jar with a rubber band
• Track how long it takes to peak
• Use or feed it at peak height

A predictable rise-and-fall cycle is actually a healthy sign. This will tell you when your ideal time to bake is moving forward.

8. Mold or Contamination

Finally, a self-explanatory issue! If your starter has mold or some other kind of contamination, it will be fairly obvious.

If you see:

• Pink streaks
• Orange discoloration
• Black or fuzzy spots

That is mold, and the starter should be discarded. This isn’t like cheese, where you can scoop off the mold and still use the rest of your starter (maybe that’s not the rule for cheese, either). You’re going to have to start over.

However, dark liquid on top (hooch) is normal and simply means it’s hungry, so don’t worry about that!

If the smell is extremely foul (rotten or putrid), it may be best to restart.

When to Start Over

Seven of the eight common problems that cause bakers to wonder “Why is my sourdough starter not rising?” are perfectly fixable, but sometimes it’s best to just scrap the starter and try again.

You may need to begin again if:

• There is visible mold
• There has been zero activity after 10–14 days
• The smell is persistently rotten despite adjustments

In most other cases, a starter that is not rising just needs warmth, consistency, and time. If you do need to start over, please don’t be discouraged. Sourdough isn’t like other types of baking. It takes a little bit to get the hang of things, and this doesn’t mean you’ve failed. Print out our Sourdough Starter Guide, and you’ll be back on your feet in a week or so.

You Will Get the Hang of Sourdough Starter

If you’re having trouble with your sourdough starter not rising, it can feel like a personal failure. But I promise it’s not. You’re learning. Growing. Practicing. One day soon, you’ll know sourdough like the back of your hand, and you’ll never be in a battle like this ever again. Instead, you’ll spend your days baking bread and making treats for all of your loved ones, stress-free.

For More sourdough Trouble Shooting, check out:

• Why is My Sourdough Bread Gummy? (and How to Fix It)
• Why is My Sourdough Not Rising?
• How to Make Sourdough Starter: A Beginner’s Step‑by‑Step + Free Printable!
• Why is My Sourdough So Sticky? (And How to Fix it!)

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