Most commonly, the issue here has to do with temperature (which is very important). If your sourdough starter is kept at a low temp, even 70°F (21°C), it will slow fermentation activity and appear to be sluggish, taking longer to rise and progress through the typical signs of fermentation.
Things that Will Kill A Sourdough Starter
High Temperatures - preheating your oven with your sourdough starter inside can lead to your starter's demise - but it would have to be completely baked for it to be completely unresponsive to some TLC.
What Does Bad Sourdough Starter Look Like? It's usually pretty obvious when your starter has gone bad. You will either see mold or discoloration (generally pink or orange). If you see either of these things, you will need to toss your starter. The smell is usually a big give away.
It needs a comfortable temperature, clean water, good food and a clean home. If it's warm, your starter will eat faster and mature faster. If it's cooler, it will eat slower and mature slower. If you prepare you starter at 1:1:1 it will be more concentrated and be ready sooner than of it was 1:5:5.
Do I have to discard my sourdough starter? It would be best to discard some portion of your starter each time you feed it unless you want to continue to let it grow. Eventually, you need to discard the used food (flour and water) that's sustained your starter during the last fermentation period.
There is no single best ratio, but I've found a ratio of 1:5:5 fed twice daily at 12-hour intervals to produce a sourdough starter that's strong and healthy. This ratio corresponds to 20% ripe starter carryover, 100% water, and 100% flour (a mix of whole grain rye and white flour) at each feeding.
If your starter gets completely covered on top with bubbles but does not rise, it is healthy but may just be a wet mix. Try reducing the water in your next feeding and see if you have different results. Also, the type of flour you are using can impede the rise of your starter.
An overfed starter can be too diluted and it will be very watery. Your workers are there, they are just overwhelmed with too much food and water. When this happens, first leave it out in the warmth overnight. In the morning discard all but a tablespoon of starter and feed it.
Most commonly, the issue here has to do with temperature (which is very important). If your sourdough starter is kept at a low temp, even 70°F (21°C), it will slow fermentation activity and appear to be sluggish, taking longer to rise and progress through the typical signs of fermentation.
It is important that you stir the sourdough starter every day in the morning and in the evening. Feed the starter. Add 60 g flour and 60 g lukewarm water, stir well to combine, and let sit out for 24 hours.
Too Hot and Too Cold
Sourdough performs really well anywhere from 74-86 degrees F (optimal 76-80).
What Happens If You Feed a Sourdough Starter Too Much Flour? If you add more flour than water into your sourdough starter jar, it will be a very stiff starter. This is not always a bad thing, and sometimes extra flour is necessary to rectify a runny starter or make the starter peak at a later time.
+ Chlorine in bleached flour and tap water will kill the yeast cultures and bacteria colonies quickly and your lovely bubbly airy starter will be no more. Or maybe it didn't get to that point and that's why the starter you're creating or maintaining isn't working.
A sourdough starter kept in the refrigerator is revived by feeding. If the starter has been in the fridge for a week or less, I'll take about 60 grams of it (equal parts by weight of water and flour) and add 60 grams of 100F water and 60 grams of plain flour. The new fed starter is about room temperature after mixing.
Why do you discard sourdough starter? Bakers often ask us, “Do I really need to discard my starter?” And the answer is yes. Regularly discarding a portion of your starter and refreshing it with flour and water keeps the microorganisms in it healthy, happy, and thriving — and healthy starter translates to better bread.
It's important to note that overfeeding can also have negative effects on a sourdough starter if done excessively or too frequently. If the starter is overfed, it can become too acidic or develop an unpleasant odor which is the result of excess food rotting in the jar.
Starter that's kept at room temperature is more active than refrigerated starter, and thus needs to be fed more often. Room-temperature starter should be fed every 12 hours (twice a day) using the standard maintenance feeding procedure: discard all but 113g, and feed that 113g starter with 113g each water and flour.
Ideally, your sourdough starter should be loosely covered with a lid or paper towel (secured with a rubber band) to keep out things like fruit flies and other debris floating around in the air. A loose lid will also stop it from drying out.
The best flour blend for creating a new sourdough starter is 50% whole-meal flour (whole wheat or whole rye) and 50% bread flour or all-purpose flour. I recommend a 50/50 mix of whole wheat flour and bread flour. Why do you need to use these two types of flour?
Feed it with 30g of strong white flour + 30g of water, stir it well, and allow it to become fully active and ready to use, this can take 2-6 hours depending on the room temperature. If you feel that the mix feels a bit thin, add a tablespoon more of flour.
If your sourdough starter won't rise anymore, reset it by putting 25 grams of starter in a jar and feed it 50 grams of flour and 50 grams of water. With this ratio, your starter should double in size in about 12-24 hours. If your starter has never risen before, follow a proven guide to create an active starter.
Things that WON'T kill your sourdough starter
METAL: Stirring your starter with a metal spoon or placing it in a metal bowl won't kill your starter. While we don't recommend making or keeping your starter in contact with reactive metals like copper or aluminum, stainless steel is harmless.
For more tang: Incorporate some rye flour and/or whole wheat flour early in the bread-making process, such as when feeding the mother culture and the preferment. Rye flour in particular will help your culture produce some acetic acid.
If your house is particularly warm (or if you keep your starter in the fridge), it could be sluggish. Try keeping it somewhere warm. I will keep mine in the oven (turned off) if it's particularly cold. If I want to speed up its rise time, I'll turn the oven light on, but not as a regular practice.