What You’ll Learn
- What healthy starter activity actually looks like.
- The most common reasons a starter stops bubbling or rising.
- Which variable to change first.
- When to wait rather than feed again.
- When colour or mould means the starter should be discarded.
Quick Answer
A sourdough starter that is not bubbling is usually too cold, underfed, recently changed or simply not yet active enough. Keep the flour, feeding ratio and temperature consistent for several feeds, then judge it by bubbles, rise and aroma rather than the clock alone. If you see pink, orange or fuzzy mould, discard it.
A quiet starter is frustrating because there is no single timer that tells you what is wrong. A culture may be healthy but slow, especially after travel, refrigeration, a flour change or a cold night.
Before changing everything, check the basics below. If you are still learning what normal activity looks like, compare this guide with the signs of a healthy sourdough starter.
First: what should a healthy starter look like?
After feeding, a healthy starter should gradually develop bubbles through the mixture, expand in the jar and eventually reach a peak before falling again. The exact rise time depends on feeding ratio, flour, starter strength and temperature.
- Bubbles throughout the jar, not only a few on the surface.
- A noticeable rise after feeding.
- A pleasantly fermented aroma: tangy, fruity, yoghurty or lightly yeasty.
- A repeatable rise-and-fall cycle once the culture is established.
Bake Slower Tip
Do not feed again just because a starter has not doubled by an arbitrary deadline. A cool starter may simply need more time. Watch the rise and bubbles before resetting the cycle with another feed.
1. Your kitchen is too cold
Temperature is one of the strongest controls on fermentation. A starter that is lively in a warm kitchen can look almost dormant when the room cools. That does not mean the yeasts and bacteria have disappeared; their activity has slowed.
Move the jar somewhere consistently warmer, but avoid direct heat. Then give it time to complete the feed. Our guide to temperature and sourdough fermentation explains why the same starter can behave very differently from one day to the next.
2. The feeding ratio does not match the starter
A very hungry starter may become acidic and weak; a large feed can also take much longer to peak because the culture has more fresh flour to ferment. Neither situation is fixed by repeatedly adding flour and water without observing what happened to the previous feed.
For a simple baseline, learn how often to feed your sourdough starter and keep the ratio consistent for several cycles. Once the starter is predictable, ratios such as 1:1:1, 1:2:2 and 1:3:3 become useful ways to control timing.
3. Your flour has changed
Starters often respond differently when you switch flour. Wholemeal and rye flours contain more of the grain and can produce visibly lively fermentation, while a refined white flour may behave differently. A change is not necessarily a problem, but it makes diagnosis harder if you also change the ratio and temperature at the same time.
If you are unsure what to use, start with our guide to choosing flour for sourdough.
4. Water may be part of the problem
Use drinking-quality water. Very hot water can damage the culture; very cold water can slow it. In most homes, ordinary tap water that you are happy to drink is a sensible starting point. If your local water has a very strong chlorine smell, letting it stand or using filtered water is a reasonable test.
5. A new or revived starter needs more time
A starter made from scratch can show an early burst of activity and then become quiet while the microbial community changes. A dried, refrigerated or travelled starter may also need several feeds before it returns to a predictable rhythm.
Do not chase the first dramatic rise. What matters is repeated activity over several feeds.
Common Mistake
Changing flour, feeding ratio, water and temperature all at once. If the starter improves, you will not know which change helped. Keep the routine steady and change one variable at a time.
What to do over the next two or three feeds
- Keep a small amount of starter rather than maintaining a huge jar.
- Feed by weight using one consistent ratio.
- Use the same flour and water for the test period.
- Keep the jar at a steady, comfortable room temperature.
- Mark the starting level and record whether it rises, how far and how long it takes.
- Only adjust one variable if the pattern remains weak.
If the starter bubbles but still barely rises, the mixture may be very loose, the flour may not hold gas well, or the culture may still be weak. That is slightly different from a completely inactive starter.
When should you throw a starter away?
A hungry starter can smell strongly acidic or alcoholic and may develop a dark liquid layer known as hooch. Those signs alone are not the same as mould.
Discard the starter if you see pink or orange discolouration or fuzzy mould. Read our guide to pink, orange or mouldy starter rather than trying to rescue visibly contaminated culture.
If it is still not working
If you have kept the routine consistent for several feeds and there is still almost no activity, work through the variables in order: temperature, starter age/recovery, feed ratio, flour and water. Avoid adding sugar, commercial yeast or other ingredients simply to force visible bubbles.
The aim is not to make the jar perform on command. It is to rebuild a culture that rises predictably enough to ferment dough.
Today You Learned
- A quiet starter is often slow rather than dead.
- Temperature and feeding ratio are the first variables to check.
- Keep changes controlled so you can see what actually helps.
- Judge repeated rise, bubbles and aroma rather than one feed.
- Pink, orange or fuzzy mould means discard.
Frequently Asked Questions
Why is my starter bubbling but not rising?
It may be too liquid to hold gas, the flour may behave differently, or the culture may still be weak. Mark the jar, keep the feed consistent and look for a repeatable rise over several cycles.
Should I feed my starter again if it has not risen?
Not automatically. If the starter is simply cold or slow, feeding too early can dilute the culture. Give the current feed time to develop unless there is a clear reason to change course.
Can I add rye flour to wake it up?
Rye can produce lively activity and can be useful, but treat it as one controlled change rather than changing several variables at the same time.
How warm should I keep my starter?
A comfortably warm, stable environment generally speeds fermentation compared with a cool room. Exact timing varies, so use temperature as context rather than a rigid deadline.
Need help diagnosing your starter?
Use the Starter Readiness Checker or ask Jim’s Baking Assistant after working through the checks above. The useful goal is to identify the variable that needs changing, not to buy your way out of a fermentation problem.
Continue Learning
Next: How Often Should I Feed My Sourdough Starter?
Build a repeatable feeding routine before moving on to more advanced ratios.
Written by Jim, founder of Sourdough by the Sea. Practical sourdough guidance for home bakers, based on clear process, careful observation and better bread.
A good way to learn
Focus on repeatability before optimisation. Use one straightforward recipe, keep notes on temperature and timings, and change only one thing on the next bake. You will learn faster from three comparable loaves than from three completely different methods.