Sourdough Starter Troubleshooting Guide and FAQ

Ripe Sourdough Starter in Weck Jar

Many people are creating sourdough starters and exploring sourdough bread baking for the first time. It’s exciting to see people diving into a subject that I’m so passionate about! 

Over the past month, I’ve received many questions on sourdough starters. To create a helpful and easily referenced resource, I’ve put together an extensive Sourdough Starter Troubleshooting Guide below. 

If you’ve already established a strong sourdough starter and are experiencing troubleshooting issues related to bread baking, please check out my Sourdough Bread Troubleshooting Guide


Here you’ll find answers to the following questions and much more: 

  • How do I get started?
  • How can I reduce sourdough discard and waste? 
  • What flour should I feed my starter? What is a feeding ratio? 
  • Why isn’t my starter more active? Should I start over? When can I start baking with it?

Note: If you have additional questions not addressed, please leave them in the comment section. 


Skip to Various Sections:

Sourdough Starter FAQ: 

Q: How do I get started?

A sourdough starter is a culture of naturally occurring wild yeast and lactic acid bacteria used to make naturally leavened, fermented bread. Sourdough staters are active organisms that requires regular feedings for best results. 

If you’re new to sourdough and interested in creating a sourdough starter from scratch, I recommend checking out my favorite sourdough resources and tools before starting. 

While I don’t have a sourdough starter recipe (coming soon!), I recommend The Perfect Loaf starter guide or Baker Bettie’s starter guide. Be patient as it can take up to 2 weeks or longer to build an active, strong sourdough starter ready for bread baking. 

Q: Do I really need a kitchen scale?

Yes. This is less of a deal-breaker for creating a starter, but absolutely vital for sourdough bread baking. 

Volume measurements are wildly inaccurate (be sure to learn how to measure flour!) and won’t yield consistent or good results for this. I recommend this basic scale, but any accurate scale with 1-gram increments will work. 

Q: Where can I find the sourdough starter jar that you use? 

I’ve found these Weck jars to be perfect because they’re straight-sided, making them easy to clean and helpful for providing a visual cue to my starter’s activity.

You want to choose a container that meets the following criteria: 1) is easy-to-clean, 2) includes a lid, which can be set askew or is not completely airtight, 3) is appropriately sized and allows your starter to grow at least 3-4x in volume. 

Q: Do I have to discard sourdough starter? How can I reduce waste? 

Yes! Discard is required to maintain a healthy sourdough starter. This actually reduces waste. Also, please remember that homemade bread is less wasteful/resource-intensive than packaged store-bought bread too. 

I scale down my starter when I’m not baking bread and scale it up during the previous night’s feeding (same ratios, just larger quantities) when I plan on making sourdough bread the next morning. Please remember that you can always scale a starter up or down (keeping the feeding ratios constant). 

If you do not discard a portion of your starter at each feeding, your sourdough starter will require larger and larger quantities of flour and water at each feeding to provide enough food for the ever-growing number of yeast/bacteria present. 

The best way to reduce sourdough starter discard is to maintain a small starter or use the sourdough discard in other sourdough discard recipes or bread baking. You can also compost it. 

Note: If you want to use the discard, but don’t want to bake every day, you can compile the discard into one jar at each feeding and store this in the refrigerator. You’ll need to bring it back to room temperature (wake it up!) or give it additional feedings, depending on what you are using it for. 

Q: Why do some starter guides call for different flours?

Methods will vary depending on a baker’s preference and experience. While you can make a sourdough starter with many flour types (do not use bleached flour for any bread baking), whole grain flours will generally yield faster results. 

Rye flour is one of the best, as it is higher in nutrients, which can speed up the process. If you don’t have access to rye flour, organic whole wheat flour is the next best option. Most starter guides will transition flour types and feeding ratios over time.

Whole grain flours contain the germ and endosperm, which become rancid if stored for extended periods at room temperature. Make sure your flour isn’t spoiled before starting. Learn more about different types of baking flour

Q: What kind of flour should I feed my starter? 

Sourdough starters can be made and maintained with many types of flours. All sourdough starters will behave differently, but different flours will yield different characteristics and flavor profiles. 

Once your starter is active, I generally recommend feeding it with the type of flour that you will most often bake with. Therefore, if you’re making mostly whole grain bread, you might want to maintain a whole wheat (or predominantly whole grain) starter. 

If you plan on mainly baking with bread flour, you might want to slowly transition it to bread flour or unbleached all purpose flour over time. See more on transitioning to different flour types below. 

Q: Can I make a gluten free sourdough starter? 

Yes, technically this is possible. Gluten free starters behave extremely differently and require a completely different baking approach. There are various flour options you can try, so you’ll need to do more research to figure out what is best for you.

I am not experienced on gluten-free sourdough baking, but there are lots of other resources (Vanilla and Bean, as well as King Arthur Flour) if you’re interested. 

Q: Can I use packaged yeast in my starter? 

No! Sourdough starters are cultures of wild yeast/lactic acid bacteria. You cannot jumpstart or create a starter with commercial or dried yeast. 

Q: What is a 100% hydration starter? What does that mean? 

Hydration refers to water quantity relative to total weight of flour. A 100% hydration sourdough starter is fed and maintained with equal parts water and flour. Most sourdough bread recipes use this type of starter. 


Starter Maintenance Questions;

Q: Can I switch or transition flours over time? 

If your starter is brand new, I don’t recommend constantly switching your flours (type or brand) as it will impact activity and can create a lot of confusion. 

However, if your starter is active and mature, you can definitely change your flours as desired or if simply run out of one type. I recommend transitioning the flours slowly over the course of a week. Remember that flours behave differently and feeding schedules might need to be adjusted. 

Q: How do I scale my starter up or down for baking or other reasons? 

Simple increase or decrease the quantities in your next feeding using the same feeding ratio (see explanation below) to maintain your current schedule. Example: 

Current Starter Feeding: 20 grams starter: 100 grams flour: 100 grams water (1:5:5 ratio) 

Scaled Down Starter: 5 grams starter: 25 grams flour: 25 grams water (1:5:5 ratio) 

Scaled Up Starter: 40 grams starter: 200 grams flour: 200 grams water (1:5:5 ratio) 

Q: Can I refrigerate my starter if I don’t plan on baking frequently?

Yes. If you don’t plan on baking frequently or are going out of town, you can refrigerate a sourdough starter for up to 2 weeks or much longer. To do this, I feed my sourdough starter as usual and allow it to sit at room temperature for just 1 hour before transferring it to the fridge. 

You’ll need to allow your sourdough starter to come back to temperature (it usually requires 2-3 regular feedings) before baking with it for best results. 

There are different opinions on this, but I don’t recommend continuous refrigeration as it can change the balance of wild yeast/lactic acid bacteria and yield inconsistent results.

Q: What do you mean by feeding ratio? Which feeding ratio should I use? 

Feeding ratios are used to indicate the ratio of sourdough starter, flour, and water in each feeding. Here are a few examples: 

1:1:1 ratio = equal amounts of sourdough starter, total flour, and total water by weight.  [Eg. 20 grams sourdough starter: 20 grams flour: 20 grams water]. 

1:2:2 ratio = [Eg. 20 grams sourdough starter: 40 grams flour: 40 grams water] 

1:5:5 ratio [Eg. 20 grams sourdough starter: 100 grams flour: 100 grams water]

*Most sourdough starter guides begin with a 1:1:1 ratio. As your starter becomes more active (more wild yeast/lactic acid bacteria), you will change your feeding ratio to account for the increased activity level. 

Once your starter is active and on a reliable feeding schedule, you can adapt your feeding ratio as needed to adjust baking timelines, etc. 

Sourdough Starter Baking Questions

Q: How do I know when my starter is ready for bread baking?

Your sourdough starter should be rising predictably and on regular feeding schedule. If your starter is barely rising between feedings or taking a significantly long period to peak using a high feeding ratio (1:1:1), it is most likely not strong enough to naturally leaven bread. 

This will vary depending on the type of flour you’re using, but your starter should at least double in volume (or more) at peak activity and pass the float test.

My current feeding and starter activity: My two-year-old starter is currently fed King Arthur unbleached all purpose flour. Using a 1:5:5 ratio, my starter peaks in about 10-12 hours when held at a temperature of roughly 75F. 

Q: Do I have to use my starter at peak activity? Can it be used early or late? 

Once your starter is active, you can play with these elements  to introduce different flavor profiles in your bread. Younger starters will have a more delicate, sweet flavor. Peaked, slightly fallen starters are higher in acetic acid and will contribute more sourness/tanginess in your loaf. 

I prefer to use my sourdough starter at peak activity and just when it is barely beginning to fall, as this has yielded the best results for me. Remember that changing these variables will impact your dough and bulk fermentation times. 


Sourdough Starter Troubleshooting

Q: My starter is developing mold. How do I know if my sourdough starter is bad?

If your starter is developing any mold (pink, etc.), throw it out immediately and start over. There is no way to fix or salvage a moldy starter. Check your flours (are they rancid? spoiling?) before trying again. 

Q: My starter isn’t showing any signs of activity and it has been several days. Did I kill my sourdough starter?

Be patient and try placing it in a warmer area of your home (76F-80F is ideal). Use your nose as a guide, as it a better tool than visual activity in the beginning. Use recipes as guidelines, not strict timelines. If your starter peaks in activity, feed it. If it sluggish, wait and give it more time. 

Many guides indicate that your sourdough starter should be active and ready for baking within less than a week. This is best case scenario and is not common. Many starters take up to 2 weeks or longer to become active enough to use in bread.

Q: My starter was really active on day 2 and 3, and then there was zero activity. What is happening?

It is common for a sourdough starter to have a surge in activity those first few days and then die down. This is normal and the results of another type of bacteria build up, not an indication that your starter is dead.

It will pick up again with time and the right types of bacteria (wild yeast/lactic acid) will increase and become more stable. 

Q: My starter is active, but is barely rising between feedings. What do I do?

Stay the course, be patient, and continue with regular feedings until it strengthens. If you’re using a smaller ratio of sourdough starter in your feedings, consider increasing it until the starter gains more strength. 

If your starter is not doubling or growing substantially in volume between feedings, it is not strong enough to leaven dough. You can certainly try baking, but you most likely will not achieve proper fermentation. 

Q: Why isn’t my starter passing the float test? 

Float tests are not fool-proof, but are generally reliable for 100% hydration sourdough starters (starters that are fed equal portions of flour and water). Failed float tests generally indicate the following: 

  1. Your sourdough starter is too young and not strong enough for bread baking. 
  2. The starter is strong and active, but not quite ready. Allow the starter to sit at temperature for another 30 minutes or hour and test again. 

Q: My ambient kitchen is very cold. What can I do?

Wild yeast prefers warmer temperatures. If you’re dealing with cooler temperatures, your sourdough starter will take longer to develop, require more time to peak between feedings, and your bulk fermentation time for bread baking will be extended considerably. This isn’t a deal-breaker, but something to be aware of. 

You can try storing your starter in an oven with the light on (please use an ambient thermometer to keep an eye on the temperature as some ovens can easily become too hot). You can also try placing your starter container in a microwave next to a warm bowl of water. 

If you’re serious about bread baking and struggling with temperature regulation, I highly recommend a bread proofing box (I own this and love it). 


If you enjoyed this post, be sure to check out my other sourdough bread baking resources: