Frequently Asked Sourdough Starter Questions

Your sourdough starter is a mixture of yeasts and suitable bacteria that co-exist to leaven and flavor bread dough. I’ve been maintaining my starter for over ten years now, regularly feeding it twice a day, every day, and the process is so familiar I don’t even think about it anymore. But it’s nothing mystical or magical, my sourdough starter is a culture I give nourishment (flour and water), and in return, it happily does work for me without even realizing it. But many uncertainties can arise along with its maintenance, and this frequently asked sourdough starter questions post is here to help.

I’ve been compiling this list of starter questions for almost as long as this website has been around. Each time I receive an email or comment asking a question about what I do in a particular situation, I’ve saved it and added the most commonly asked questions below.

If you’ve arrived here before you have a starter, it might be worthwhile to have a read-through to internalize some of these questions and answers. Then head to my guide to creating a sourdough starter and get started.

How do I create a sourdough starter?

I’ve written a detailed post with pictures and clear instructions on creating a sourdough starter in 7 easy steps.

In your starter guide, you say to use whole-grain rye flour. Can I use something else?

I call for whole-grain rye flour when creating a starter because the additional nutrients in rye flour help speed up the process. You can certainly use whole wheat flour or even white (sifted) flour if you’d like, but I find rye flour to be the most effective flour at the beginning. If you don’t have rye flour, then whole wheat works!

I think my sourdough starter died. Is it dead?

It’s normal to see a lapse of activity at some point when first creating a sourdough starter—this is normal. The initial proliferation of action at the beginning of creating a starter is from a different type of bacteria in your mixture that will eventually be replaced by the kind we are looking for (lactic acid bacteria). Keep feeding, and discarding, as I outline in my creation guide. Eventually, your mixture will slowly become more and more acidic (low pH), killing off other bacteria and allowing the beneficial yeasts and bacteria we are looking for to take hold.

I’ve been following your starter creation guide, but nothing is happening. What’s wrong?

The most common problem I see people face is low temperatures: it’s easier to create your starter if you keep it warmer. Cold temperatures (below 70°F/21°C) will slow the process down significantly, whereas warmer temperatures (around 76-82°F/24-26°C) will speed it up. Try to find a warm spot in your kitchen to keep your starter, or use more lukewarm water for feeding. For more information on starter and dough temperatures, see my post on the importance of dough temperature.

Should I cover my sourdough starter?

I like to keep mine covered loosely to keep anything from falling inside the jar and to keep the starter from drying out. The lid does not have to be airtight. I loosely place a glass lid on top, but it’s not sealed shut.

When is my starter strong enough and ready to bake with?

Once you see predictable signs of fermentation (rise, bubbles, a transformation in aroma from sweet to sour, etc.) each day, it should be strong enough for baking. When creating a starter from scratch, you might see a spur of activity at the beginning of the process, but you want consistent signs of fermentation day after day before it’s strong enough to use for leavening. Typically, when creating a new starter, this is after 5-8 days.

Do I have to make a levain or can I use part of my sourdough starter?

It’s always an option to use your starter instead of making a levain. But, for most recipes, I prefer making a levain so I can control the flour going into the levain, the ripening timeline, and when I use it to mix into a dough—all of this without having to adjust my continually maintained sourdough starter.

For example, I might make a levain with all white flour and use it before being overly ripe for my cinnamon rolls. This will help to ensure the end rolls will not have an overly sour flavor.

What kind of container should I use for my sourdough starter?

You can use just about anything. I like to use clear glass containers to observe the sides and bottom, and these Weck jars are my favorite. They have a glass lid that rests on top just in case too much pressure builds up inside the jar from fermentation. Canning glass jars are also a perfect choice.

How often do you change or clean your sourdough starter container?

Use the same jar daily and keep it as clean as possible. During a feeding, discard part of your starter per usual and then scrape down as much residual starter as possible, reincorporating it back into the mixture. Then wipe the top and sides of the jar with a towel to remove any remaining liquid. If you can get the top half reasonably clean, that’s good enough. The bottom half of the jar will most likely be covered when your starter rises during the day, anyway.

What kind of water should I use to feed my sourdough starter?

Regular drinking water from the tap is just fine. Fill up a large container and let it sit on the counter overnight before using it to allow any chlorine in your tap water to dissipate.

I hate throwing away excess sourdough starter after feeding. What can I do with the discard?

Cook or bake with it! You can use leftover starter into banana bread, waffles, pancakes, tea cakes, muffins, pizza, cookies, and so on. If you want to use less flour overall, check out my guide to maintaining a smaller sourdough starter. Aside from using sourdough discard in other foods, I will almost always compost any leftovers, only using the trash as a last resort.

Can I refrigerate my sourdough starter?

I have successfully refrigerated my starter many times, typically when I’m going out of town on vacation for a few weeks or won’t be baking for a while (rare!). To prepare for the fridge, I will wait until the starter needs a refreshment, discard all but 20g of ripe starter, and then refresh it with 100g flour and 80g water (I like the culture to be a bit on the stiff/dry side). After refreshing, let it sit on the counter for 1 hour, then toss it into the fridge. I will usually use the same Weck jars for this, and the cover will be loosely placed on top so nothing can fall in, but excess gasses can escape.

When I want to bake again, I will remove my starter from the fridge, let it ferment on the counter for a few hours, and then feed it as I would normally. I will do this a few days before I plan to bake to get the culture back up to strength.

See my post on storing a sourdough starter for tips on keeping it in the fridge or other methods for longer periods.

Why doesn’t the sourdough starter float test work?

The float test is a good general indicator for when a starter or levain has significant fermentation, but I find it is not 100% reliable in testing for when a starter is ready for use. It can lead to false positives, but, as I discuss below, when your starter makeup is not with a majority of white flour at a moderate to high hydration, it will also rarely float, even if your starter is ripe. Instead of using the float test, I look for signs of strong fermentation and ripeness.

My starter doesn’t seem as strong as yours (fewer bubbles, slow rise, etc.). What’s wrong?

If you’ve just created your starter, give it time to ripen. With consistent, predictable refreshments, you will “train” your starter into strength, and it will display the same signs of strong fermentation each day. Temperature is also incredibly important here: keeping your starter relatively warm (I prefer 76-80°F/24-26°C) will encourage increased activity.

Why does my sourdough starter take a long time to ripen?

Several factors play into the fermentation vigor of your starter, and the most important one is temperature. Try to find a warm spot in your kitchen to keep your starter, or use more lukewarm water to feed it. Shoot for 76°F – 80°F (24-26°C) ambient temperature for increased fermentation activity. Maintaining a stable temperature is important, and if there’s one thing I like to focus on with my starter, it’s temperature.

Flour selection also plays into the fermentation activity; the more whole grains you use to refresh, the higher the fermentation rate in your culture.

And, of course, the amount of ripe starter you carry over from feeding to feeding plays a significant role. The larger the percentage, the faster your newly refreshed culture will ripen.

All of these variables can be tweaked to speed up, or slow down, the time it takes for your starter to ripen and need a refreshment. My preferred method for changing my starter’s ripening timeline is to adjust the amount of starter I leave in the jar for each refreshment (the carryover). If it’s summertime, I will usually carry over a smaller percentage of ripe starter (15% or so) at each refreshment to slow things down so I can maintain my twice-a-day refreshment schedule. If it’s winter and temperatures are lower, I’ll carry over an increased amount of ripe starter (25% or so) into my next refreshment.

How many times should I feed my sourdough starter each day?

This question is very temperature and flour-dependent. If the ambient temperature in your kitchen is on the warmer side, 75-80°F (23-26°C), then you’ll find your starter ferments much faster than if it were cooler (less than 75°F/23°C). Likewise, you’ll see higher fermentation rates if you use a large percentage of whole grains in your refreshment.

I prefer to feed my starter twice daily to keep it healthy and ready to bake at any moment. But then again, I bake very, very frequently. If temperatures are not overly high, I recommend a single daily feeding. If your starter falls significantly in its jar, looks broken down and loose, and smells like harsh vinegar or paint, try using a smaller percentage of ripe starter at each feeding. You can also find a cooler spot in your kitchen or use colder water to feed.

For example, in the summer (typically 75-78°F/23-26°C in my kitchen), I feed my starter twice a day, but even then, I have to reduce my ripe starter carryover percentage. Instead of my usual 20-25% in the winter, I drop it down to 10-15% and find a shaded, cool spot in my kitchen to slow things down. For more information on this, including pictures, see my post on maintaining your sourdough starter.

How can I adjust my sourdough starter feeding schedule around my work schedule?

For a very in-depth discussion on how to maintain your starter in the fridge during the week and use it to bake on the weekend, head over to my Weekend Baking Schedule guide! Additionally, see the previous question for what “tools” you can utilize to speed up or slow down your starter’s fermentation rate.

Can my sourdough starter be above (or below) 100% hydration?

Of course. When it’s significantly hot and dry here in the summer, and the flour seems to need more water, I’ll increase my hydration to 105% or higher as required. You can adjust the amount of water you use at each refreshment so the mixture displays the desired viscosity. As the humidity level in your environment changes, adjust the hydration up and down by 5% to compensate.

My sourdough starter gets a clear, thin liquid that smells like alcohol on top. Should I throw it out?

You can either discard this liquid (or “hooch,” as it’s commonly called) or stir it back into the culture. I typically stir it all in together. This can be a sign you’re not feeding your starter often enough.

Why doesn’t the “float test” ever work with my sourdough starter?

When the hydration of your starter or levain is sufficiently low, the “float test”1 becomes less accurate and, in most cases, doesn’t ever pass.

Instead of using the float test, observe the actual culture and its progress. You want to see a slightly domed top to the levain with lots and lots of bubbles at the sides (see the picture before this section). You’ll see and smell significant fermentative activity if you peel back the top. These are signs that your levain is ripe enough to use in your final dough mix.

How does high altitude affect my sourdough starter?

You might see increased fermentation activity at high elevations. See my baking at high altitude guide for more tips.

What’s next?

If you’re having issues with your sourdough starter and haven’t found help above, post at our member community for help!

For more starter-related things, look at my ultimate guide to sourdough starters for help and advice with feedings, maintenance temperatures, long-term storage, and much more.

Happy baking!