Why is my sourdough starter not rising? Causes and fixes

A starter that won't rise is probably not dead. King Arthur Baking says a starter is really hard to kill. It may be cold, young or hungry, or it rose while you weren't looking. Work through these checks in order.

First, make sure it didn't rise and fall already

A starter doesn't stay at its peak. King Arthur's starter lifecycle chart shows about 6 to 8 hours of rising, a peak of about 2 to 3 hours, then a fall. So if you feed it and check 12 hours later, you may have missed the whole rise.

Look at the side of the jar. Once a starter falls, it no longer looks doubled. King Arthur says fresh residue on the side of the container is the evidence it did double. Streaks above the current level mean your starter is working.

Next time, mark the level after feeding with a rubber band or an erasable marker.

Is your kitchen too cold?

King Arthur says that at 75°F (24°C) or above, a healthy starter should double within 6 to 8 hours of feeding. Below 68°F (20°C), fermentation can take much longer. University of Illinois Extension says 70–82°F (21–28°C) works best. Illinois and Clemson extensions give a faster 4 to 6 hours to double. King Arthur says temperature and your starter's health both affect timing.

If your kitchen is chilly, King Arthur suggests:

• Move it somewhere warmer, like the top of the fridge or near a radiator or vent.
• Use a heated mat.
• Feed it with warm water, 80–90°F (27–32°C), instead of cool.

Don't overdo it. Colorado State University Extension says fermentation can run too fast or even stop when it's too hot for your own comfort, and King Arthur notes that yeast dies at 140°F (60°C).

Is your starter still young?

King Arthur has a name for a new starter that stalls: the starter fake out. After the first few days, a new culture can double fast and look ready, then suddenly stop. The early rise is a rush of activity as wild yeasts and bacteria start feeding. As the culture gets more acidic, some microbes die off and it looks inactive. King Arthur's tips for new bakers describe one set of bacteria giving way to another, with the starter resting while neither is dominant.

King Arthur says a brand-new starter might stop rising for a week or more, even with regular feedings. Keep feeding it, and a strong yeast colony takes over. This can also happen when you wake up a dormant starter. For dried flakes, see how to revive a dried sourdough starter.

Sources disagree on how long it takes: King Arthur says a week or less up to a couple of weeks, longer in a cool kitchen; South Dakota State Extension says 7 to 10 days on average; Illinois Extension says 14 days to a month. King Arthur says to watch the benchmark, not the calendar: a starter is ready when it reliably doubles within 6 to 8 hours of feeding.

Is it hungry?

King Arthur says a starter left unfed on the counter for a few days, or in the fridge for a couple of weeks, becomes less active. Once it has eaten all its food it goes to sleep, and a gray layer of liquid alcohol, called hooch, forms on top. Sharp smells like alcohol, acetone or vinegar are hunger signals too, not spoilage.

King Arthur suggests feeding it at room temperature every 12 hours until it doubles within 4 to 8 hours. A fridge starter needs a couple of days of room-temperature feedings before you bake. See how often to feed a sourdough starter for a schedule, and is my sourdough starter dead? if it's been a long time.

Give it some whole grain flour

King Arthur says whole grain flour gives the yeasts and good bacteria more nutrients, which means a stronger rise. Add rye, whole wheat or pumpernickel at 10% to 20% by weight of the white flour in a feeding. For a 50 g feeding, that's roughly 5 to 10 g. Illinois Extension suggests switching a sluggish starter from all-purpose or bread flour to rye. Both recommend unbleached flour.

Check the consistency

A starter that's too thin can bubble but not grow. King Arthur says some starters are so liquid that there's not enough structure for them to expand, so the bubbles rise and escape. If yours pours easily instead of being gloppy, feed it a little more flour until it thickens, or use higher-protein bread flour.

Aim for something like muffin batter, which is how King Arthur describes a fresh feeding. A thicker starter isn't automatically a problem: King Arthur's stiff starter has twice the flour of a regular equal-parts starter and still doubles in about 8 hours.

Check the feeding ratio

A 1:1:1 feeding means equal weights of starter, flour and water, such as 50 g of each. It's the minimum King Arthur recommends. The more flour and water you add relative to the starter, the slower it rises. In King Arthur's tests at 78°F (26°C), 1:1:1 had doubled after 4 hours, 1:2:2 peaked at about 8 hours, and 1:4:4 took about 12 hours. If your starter seems sluggish, go back to 1:1:1.

What about chlorinated water?

King Arthur says chlorine and other chemicals in tap water aren't ideal for a starter, but you don't need bottled water. If your tap water smells of chemicals, leave it in an open container at room temperature overnight before using it. Illinois Extension agrees tap water is usually fine, but says very hard or heavily chlorinated water may keep a starter from fermenting well.

When not rising means start over

Very occasionally, bad bacteria get in and affect a starter's ability to rise. Throw it out and start fresh if you see:

• any mold, fuzzy or colored;
• a pink or orange tint, streaks or liquid;
• a putrid smell, like garbage or rotting food.

Colorado State Extension says to clean and rinse the container thoroughly before starting over. Gray or dark liquid on top is just hooch. See what your starter's smell means if you're not sure.

How Sourdough Starter Tracker helps

The app's Troubleshooting screen covers "My starter isn't rising at all," with the likely causes (too cold, or still young) and what to try: a spot at 75–80°F (24–27°C) and some whole wheat flour. A Quick Health Check lets you log smell, rise, bubbles and consistency, with an optional photo, so you can compare day to day. Making a new starter? The 14-day Create Your Starter guide shows what to do and expect each day, and tells you when it's mature. Each starter's face shows when it's getting hungry. Premium, a one-time purchase, adds Smart Health Tips, which look at your temperature, feeding ratio and more.

Sources

• King Arthur Baking: Why is my sourdough starter not rising?, Beware the sourdough starter fake out, 10 tips for new sourdough bakers, How to make sourdough starter, Creating a starter, Sourdough feeding ratios, Stiff sourdough starter, Sourdough starter troubleshooting, Sourdough Tips and Recipes (2026)
• University of Illinois Extension: Sourdough 101
• Colorado State University Extension: Sourdough starter best practices
• South Dakota State University Extension: Sourdough starters
• Clemson Extension: How to make, feed and bake with a sourdough starter