Should You Clean Your Sourdough Starter Jar?

So you’ve gone ahead and joined the sourdough bandwagon, or perhaps this is an old hat for you – and you’ve had the same sourdough starter for several years. Either way, at one point or another we’ve all asked ourselves whether or not we should clean our sourdough starter jar. 

The short answer is no, you don’t need to clean your sourdough starter jar. Or rather, it isn’t all that necessary. You can use the very same jar every day, simply make sure you are maintaining as clean an environment as possible.

Feed as you normally do, only make sure to scrape as much of the leftover starter down the sides of the jar to join the mix at the bottom. After that, merely wipe up the top half of the sides, the top, and the lid with a paper towel or clean cloth.

A Wee Bit of History: Sourdough Starter

Although sourdough bread is quite trendy at the moment, sourdough bread can be traced back to ancient Egypt as the oldest known appearance of leavened bread. Very likely accidentally discovered, its lighter texture and superior flavor likely was a result worth acquiring on the regular. Fast forward a lot, and we’re in North America a sourdough tradition arose amongst miners and the like during the Gold Rush. These folk would often be found carrying their sourdough starter in pouches around their necks. No jars, pouches. This gives you an idea of just how resilient a good sourdough starter can be.

You Can Clean Your Sourdough Starter Jar, but You Don’t Need Too

The question of whether or not you should clean your sourdough starter jar comes up a lot, particularly for those who are just starting down the long and winding road that is sourdough. You may have noticed that the sourdough bread you bake, stays fresh a little longer than yeasted homemade bread. The fresher aspect of sourdough bread is attributed to the extra fermentation which traps more moisture in the dough.

A sourdough’s long life may also be due to its ability to inhibit mold growth. The bacteria in some sourdough starters create compounds that eliminate mold, basically a natural preservative.

To give you an idea of just how wild this is, in a 2013 research paper published in Applied and Environmental Microbiology,  researchers observed a French strain of sourdough starter, called Lactobacillus hammesii and discovered that this particular strain pumps out a potent antifungal that was able to resist mold for up to 15 days! That’s one seriously strong natural preservative.

So, now we understand why there is no need to wash your sourdough starter jar regularly. That being said, it doesn’t mean that there won’t be an occasion where it’s absolutely necessary that you wash your jar.

When & Why You Might Need to Clean your Sourdough Starter Jar

Because we now know that a good sourdough starter essentially wards off mold, you may nonetheless encounter mold. Why would mold be growing, if the environment isn’t supposed to allow it? Well, it could be a couple of things: 

  1. The starter isn’t healthy – We’ve all been there, life got busy and you’re not baking as often as you were, and the sourdough starter has been neglected. An infrequently or irregularly fed starter can get unhealthy enough to weaken the environment and thereby allow mold to grow.
  2. Cleaning the jar too often – if you find yourself cleaning the jar, because esthetically the crusty bits are just not doing it for you, well that could be the culprit. An improper clean or residual soap left in the jar can be the root of a mold issue. Every time you clean you’re using soap and a sponge that could introduce a harmful bacteria to the home of your sourdough starter.

The key is washing down the sides of the jar and feeding it regularly. Those two simple tasks should be ample effort on your part, to keep mold at bay.

If you do happen to see mold growing on, or around your starter, it’s best to toss and start over (…unless you happen to have a backup for just such an occasion or you can ask a friend for some of theirs).

If you are starting over, thoroughly cleaning and sterilizing your jar is an ideal starting point. You’ll be providing your starter with as clean a home as possible to produce a superb environment for all those healthy microbes to grow.

Basic Sourdough Starter Hygiene

As long as you use ceramic, glass, or a stainless steel container, it isn’t at all necessary to clean your sourdough starter jar. Feed your starter with new flour and water, using a silicone spatula to scrape down the sides of your jar and keep them as clean as possible. You may also want to scrap the top of the jar when there’s a build-up of dried up sourdough starter. 

If you want to clean your jar go ahead. You can do so about once or twice a year no more than that.

Make sure to sterilize your jar by boiling it in hot water and don’t touch it directly with your hands. always use tongs and gloves. this way you are ensuring you will not be introducing new bacteria to the starter.

If you are in the market for a new sourdough starter jar then check out this link for cool new sourdough starter jars that have been popping up on the market lately. They come with a built-in thermometer ( very smart ) and a magnet strip on the back to mark the level of your starter after feeding ( also smart ) Thi product is reasonaly priced the built in functionality of it is totaly worth it.


Hi, my name is Amit. I started baking at a young age at my father's bakery. I hope I can answer some of your questions and hopefully you will find some hidden gems to help you out with your home baking skills.

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