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What Should Sourdough Starter Smell Like?

A few times in the past few days I've been asked what sourdough starter should smell like. And I've blown the question off. "I cover that in the sourdough starter primer!" I say. Only.... I haven't.

Yeah, I mention smell in passing here and there. But never in any detail. At least not much past it smells "nice", "awful" or "like acetone (cheap fingernail polish remover)." Of course, two of the hardest things to share in words are smells and tastes. We're better at telling others how things look. Which is why wine, tea and even coffee lovers come up with such strange and tortured descriptions. Here's a description from a coffee ad. "For the loyal supporters who love their company but are nostalgic for taste notes reminiscent of Catfish Hunter or Charlie Parker: dark, oily, stanky, musty, full-bodied, peppery, meaty, and seasoned." Really? What does that even mean? Oddly enough, my fingers weren't on the right home spots on the keyboard and "really" came out as "freaky".)

Still, never let it be said I don't go the extra mile, or sniff, for Sourdoughhome fans!

There are a few categories to consider. Starter as it being created, before it stabilizes. Starter that has matured, when it is healthy and active. The neglected bottle of starter at the back of your fridge or - worse yet - on a countertop.

To recap what we discussed in the sourdough starter primer, flour has a wide range of bacteria and yeast on it. When you mix water with the flour, they become more active. They eat, they reproduce, they fight for dominance in a very Darwinian battle. There is a succession of bacteria and yeast in a starter over the first week. I discuss this in the "Sauerkraut und Sauerteig" blog post. We have found the same sorts of bacteria are in the succession for sauerkraut as with sourdough.

First there are coliform bacteria. They increase the acidity of the starter. At some point, the coliform bacteria can no longer tolerate the acidity they have created. (Among living organisms, only teen-aged human males can live in any serious concentration of their own waste.)

This sets the stage for the next round of organisms, the Leuconostoc bacteria. Many times these stages are over in hours or a day. Which causes the starter to become very frothy. However, Leuconostoc bacteria aren't in it for the long haul. They don't have the strength to raise dough. I get a fair number of emails that comment, "My starter was frothy in just a day! But it wouldn't raise bread!" If you use the starter at this point, you'll be disappointed. Which is why I suggest waiting to use a starter until it is at least a week old and it can consistently double - or more - in size between feedings. Again, the Leuconostoc bacteria makes the starter more acidic, until they can no longer survive in the acidity they created.

That acidity sets the stage for Lactobacillus bacteria, which are the characteristic bacteria in sourdough. Some people use pineapple juice or orange juice to skip the earlier stages of the sourdough starter development and get right to Lactobacillus bacteria. While I don't think that is a bad idea, I've also never found it to be necessary. In any case, the Lactobacillus bacteria make the starter more acidic, but with proper starter care the acidity remains in a range the Lactobacillus bacteria can tolerate. The acids that the Lactobacillus bacteria are primarily the mild lactic acid and stronger acetic acid. The acidity that the bacteria creates kills off competing bacteria, and creates an environment few yeast can survive. This is the last stage of sourdough starters, a symbiosis of Lactobacillus bacteria and acid tolerant yeast.

At one time it was believed there were something like three strains of bacteria and five strains of yeast that could create a stable sourdough starter. Now, scientists have identified 40 or 50 strains of each that can work. While interesting, this isn't of great importance to the practical baker, after all, it's not like we can - or have a real reason to - identify the strains in our starters. As long as our starter can make good bread, we really don't need to know what's in the starter.

OK, now, let's talk about smells! (You thought I'd gotten lost in another five paragraph digression, didn't you?) The smells that are produced at each stage depend on the kind of flour you are using and the "critters" who are working on the flour. The first stages can be unpleasant. Think dirty sweat socks. Or worse. However, in the early stages just observe and keep feeding the starter. Bubbles and smells are signs that something is happening in your sourdough starter, and that's a good thing.

When your starter reaches the last stage and stabilizes it will develop its own characteristic smells. However, despite the name "sourdough", a healthy sourdough starter usually has a fresh yeasty smell with, perhaps, a bit of an astringent note to it.

The idea of using a fresh starter bothers some people. They seem to think that that you get sourdough bread by adding a strongly flavored sourdough starter to dough in much the same way that adding chocolate chips to cookies makes them chocolate chip cookies. Using a fresh smelling starter just doesn't make sense to them.

The difference is that when you open the bag of chocolate chips, the chips are as chocolaty as they are ever going to be.

However, the flavors and aromas of sourdough bread are developed through fermentation of the dough, and the flavors and aromas depend on the skill of the baker and what the baker is trying to do. I and the professional bakers I know use a fresh and active starter so that it will be able to survive a long fermentation and still raise the bread dough. Sourdough breads can range from having very mild sour tastes to very assertive sour tastes. Different people prefer different tastes, and different breads call for different levels of sourness.

I make a cinnamon raisin bread with sourdough. The sourdough flavor is very subtle, and many people don't know it's there. However, the bread has an uncommon depth of flavor, and it lasts longer than most breads because of the sourdough.

If you don't feed your starter for a while you'll notice other aromas creep in. When yeast eats sugars and starches, they produce carbon dioxide and alcohol. So, you'll notice more of an alcohol smell. If you still don't feed your starter for a longer period of time, the starter will develop some serious funky smells. What sort of smells? It depends on the critters in your starter, the kind of flour you are using, the temperature of the starter and how long it's been since you last fed the starter. However, I've had starters that were in serious trouble develop pronounced acetone aromas. Acetone is the main ingredient in cheap fingernail polish remover. If you smell that, it's probably time to start a new starter.

Refined white wheat flours, such as all-purpose flour, bread flour, high gluten flour, and Patent flour lead to milder aromas in the starter. Whole grains, such as whole wheat flour and rye flours tend to produce more pronounced and sharper smells in your starter. Switching from white flour to whole grain flour will change the smell of the starter in just a few days. And if you switch back to white flours, the smells of the starter will subside in another few days.

A friend tells me that his rye flour has aromas in it like over-ripe apples. Some people who make starter the way Gerard Rubaud does report apple and nutty aromas. I wish I could say something more definite like, "A fresh starter smells of the flour used to make it, and will have a fresh aroma with hints of woodruff, sage and chalk. An older starter will smell strongly of gym socks." However, I can't do that. Sourdough starters can, and do, have different smells. So, smell your starter and learn how it smells when it's fresh and when it's tired. A few bakers tell me they learn more about their starter by tasting it than by smelling it, so give it a taste too! Over time you will learn how your starter should smell and taste!

Except for one starter, all of my starters have smelled pleasant and clean. That exception was a commercial dried starter that I had purchased at a health food store. When it was active it smelled (sorry, this is going to be gross) like a wino's vomit. (Don't ask how I know about that. It's not that interesting a story. It involves an emergency stop at a convenience store on the wrong side of the tracks.)

I called the vendor and they said the smell was to be expected. Would you be surprised if I told you that something that smelled like that made bad bread? You shouldn't be surprised. My family refused to eat a second bite. I finished off a slice wondering, is it supposed to taste like this? As computer types say, garbage in, garbage out.

53 thoughts on “What Should Sourdough Starter Smell Like?”

    1. I can give you an unequivocal answer. Maybe.

      It depends on who you talk to. Some experts say to pitch it. Some say it can be saved. It may depend on how strongly it smells of acetone.

      When this happened to me I worked hard to rehabilitate the starter and it started working well. Until I skipped two feedings and then the acetone came back.

      We imagine that our starters are pure things with one yeast and one bacteria in them. The truth is much different. The grain the starter was started with had many strains of bacteria and yeast on them and a few became dominant. The Public Science Sourdough Project talks about this and shows what is actually in people’s starters.

      The issue is that when you don’t feed your starter something happens. The yeast and bacteria eat all the carbs and then they go hungry. At this point it’s unclear to me what happens. (Microbiologists, feed free to chime in!) Either a lesser strain which can eat protein takes over, or perhaps a main strain learns to eat protein. When they eat protein, they produce the acetone smell.

      The issue is when you make a dough with them, they REALLY weaken the dough and instead of dough, you get goo in less time than it takes the dough to rise.

      If you feed the starter religiously and frequently, there will be carbs and either the regular strains of critters take over again or the main strains switch back to eating carbs. However, in one case the lesser strains which enjoyed a day in the sun are looking for a chance to take over again or in the other the strains that learned to eat protein are ready to do it again. So, skip a few feedings and you’re back where you were.

      Feel free to try to rehabilitate your starter, you could have better luck than I did. But my best advice is to pitch it, sterilize everything it came in contact with, and start a new starter.

      1. I’m doing this for the first time ever. I have seen there are different instructions to start a starter. The one I found was to feed it once every 24 hrs. Today was day 3. I left it in the oven overnight without the light. When I opened it, it stunk (sorry) but looked bubbly, grayish on top, and looked like it had risen and fallen. I’ve fed it and set it to the side. Don’t think I’ll let it sit in the oven tonight. Do you think it’s still good?

        1. For a number of reasons, I don’t comment on other people’s methods. The main one is that since they aren’t my methods, I am not familiar with them.

          My suggestions are to either try my approaches to starting a starter, or ask the person whose instructions you are following.


  1. Hi, thanks for the helpful advice. I have two starters on the go, one further along than the other. The one that is about two weeks old is rising and frothing well but smells a little alcoholic (even though I have been feeding it regularly). The younger one (about a week old) is also frothing well but is starting to smell slightly cheesy. Neither smells bad as such, just very noticeably different from one another and also from starters I’ve had in the past. Any thoughts would be much appreciated.

    1. Hi Emily,

      Not all starters are the same. A while back I read there are over 50 known strains of bacteria that can develop into a sourdough starter. When I first got into sourdough, the number of known strains was around 5. They behave differently in terms of speed of rise and flavor. Some people collect strains of sourdough – at one time I had 6 or 7. There wasn’t enough room for important stuff in my fridge so I narrowed it down to 1, the one I liked. My feeling is many people have trouble keeping them pure and distinct. Also, many people won’t work with them often enough to really know how each of them work and how to get the best out of them.

      So, enjoy their differences and the baked goods they help you make.

      Best wishes,

      1. Thanks Mike, today I’m doing a test bake using the two differential starters. It’ll be really interesting to see if there’s a noticeable difference in flavor. Should be a fun experiment.

  2. Hi, how do you know there’s different stages of bacteria and how do you know how many strains are in the starter?

    I have a starter that smells like vinegar… What kind of stage is that? It’s 7 days old.

    According to this blog, does it mean that the more days you feed, the more strains it has?

    1. Hi Vale,

      There are two main ways I could know the answers to your questions. I could be a microbiologist, or I could read research done by microbiologists. I’ve read the research done by microbiologists, and have summarized it here. When you start a starter with whole grain flour there are many microorganisms on and in the flour. Adding water lets then grow. And then a Darwinian survival of the fittest begins. In the end, usually two microorganisms are dominant by orders of magnitude. We talk about the procession of microorganisms in a blog post about sauerkraut und sauerteig and even name names.

      We looked at this matter, and the organisms in charge, again in a blog post titled ““Another Delicate Matter” and then again in the blog post titled, “Another Look At The Delicate Matter“.

      In the main article on starting a starter, we go into some detail as to what is happening when you start a starter. At the end of that article, we point to three articles on different ways to start a starter. There are a number of tabs to that article that give different views of starting a starter. One of the tabs is Starter Troubleshooting which gives a lot of information on stubborn starters.

      It isn’t clear from your note whose method you are using. The main thing I recommend is that you feed a starter twice a day (more or less every 12 hours), and that you feed it enough to double it in size, and that you feed it equal weights of flour and water. Different people have different ratios. If you feed it less, or less often, you’ll have trouble.

      One of the things that sourdough produces is acetic acid, which is commonly called vinegar. Which suggests that your starter is working.

      The test I like to use to answer the “is my starter ready to make bread” question is that to be trusted a starter needs to be at least a week old, and able to double in size between feedings.

      It looks like you’re close to getting there, keep going,

  3. Hi Mike,
    Thanks for the wonderfully detailed article. My first time making a rye sourdough starter here. My question is, is it possible that the starter smells fruity and slightly sour to me, but smells like stinky vomit to the rest in the family (poor them, they are refusing to eat anything I touched with my fingers)?

    1. Hi Tina,

      Sourdough is a wild and crazy thing. There are something like 50 different strains of bacteria that will do the job and a good number of yeast. As a result, starters smell and behave differently.

      Smells and tastes are very personal. Many people feel that cilantro tastes like soap. My wife is one of them, so we have to order her Mexican food without cilantro.

      The good news is most of the less pleasant smells in a starter will usually go away if you keep feeding the starter at room temperature. The first starter I purchased smelled very bad and I never got it to stabilize, so I tried making my own which was much more successful. So, if your starter keep stinking, you might pitch it and start over.

      Hood luck,

  4. Interesting you mention the start that smelled like “a wino’s vomit” b/c I just revived an old starter we had in our fridge. The thing hadn’t been touched since 2013. It started out smelling like alcohol, not quite the strong acetone scent you mention, but I would definitely describe hints of it… After a day of feeding it, it smelled much better, pleasant even. The two days that followed it smelled yeasty and mild. BUT this morning I definitely would describe the smell as kinda vomit’ish! Maybe more like cheesy and after I fed it, it mellowed to kind of a more buttery smell? After a few hours it’s back to kinda cheesy, not like a mmm I want to eat that cheese smell, more like the boxed Mac and cheese that comes with the sauce pack already saucy (i.e. not the powdered packets). I don’t know, but it was not what I expected and I wouldn’t describe it as a pleasantly yeasty smell! Is “cheesy” a normal smell??


    1. Hi Jenna,
      Thanks for your note. Yeah, we’ve all had unpleasant smelling starters. Normally, if you keep feeding them the settle down and “fly right.”

      Cheese is a normal smell – for cheese. If you haven’t used milk in your starter (I don’t, but some people do), it’s not clear what the issue is. My shoot from the hip guess is there is something in the starter that really doesn’t belong. The first way to deal with this is to feed your starter twice a day. Discard half of your starter and then add equal amounts of flour and water to double the size of the starter. Put another way, if you have 100 grams of starter, move 50 grams to a clean container to minimize the chances of the container continuing the contamination, then add 25 grams of water and stir the starter, then add 25 grams of unbleached all-purpose or bread flour, even if you are a whole grain baker. After a few feedings the starter should smell better and you don’t need to keep moving it to new containers. I’d keep feeding it twoce a day for a week or so to make sure the good microorganisms are well established and the bad ones have been beaten into submission.

      I would discard the part of the starter you didn’t feed for a while. Usually, I like to save the discard and use it for other projects. However, when the starter smells off, I’d rather err on the side of caution. Once the starter smells good and doubles in size between feedings, you can again save the discarded starter. We have a number of recipes that use discarded starter. Also, if you are a whole grain baker, you can again start feeding your starter whole grains. White flour adds fewer microorganisms to the starter than whole grain flour, and at this point we suspect the starter is impaired so it doesn’t need outside competition.

      That is the first approach. What if it doesn’t work in a few days? At that point, I’d suggest pitching your starter, washing all your starter handling equipment in the dish washer and starting over. We have a number of good ways to start a starter, but my favorite remains my way.

      Good luck,

  5. Hello … wondering, in the first week of the starter at room temp, are any of the bacteria dangerous for consumption. Can they make people sick? I forgot to give my starter the second feed suggested, so I’m keeping it room temp one more day to get that second feed in a 24 hr period. It’s been growing and bubbling with foam. And it not smells and makes me want to vomit. Before it just smelled like flour.

    1. Hi Erica!
      The first week or so, until the starter is reliably doubling in size between feedings, are spent in a wilderness, time where strange things happen. The first bubbles are caused by pneumococcus bacteria, then they make the starter too acidic and die off, making way for leuconostoc bacteria which foam like crazy but don’t have the strength to raise bread. They do, however, make the starter more acidic at which point sourdough bacteria take over, along with one of the strains of yeast that can tolerate the acidic environment. Bakers yeast can’t tolerate the acidity, and if you add bakers yeast toa starter, it goes away very quickly. We talk about this in an earlier blog post.

      All that said, since I don’t know what bacteria are in the starter at the beginning, I can’t say it’s safe. I prefer to err on the side of caution, so I don’t trust a starter that is less than a week old and which can not double in size between feedings.

      Once your starter stops smelling like wet flour, that’s a sign that something is happening which is good. The smells will change as you keep feeding the starter. Almost every time as you keep feeding the starter it will settle down and being to smell better and behave correctly. Too many beginners freak out when the starter smells bad and pitch it, only to get there again in a few days. So… just keep feeding it twice a day.

      You mention refrigerating your starter. I’d suggest against refrigerating so young a starter. Debra Wink has observed there is a noticeable change in her starters about 14 days after the first signs of yeast activity. Many people have reported that the starters will continue to mature and gain in power for 60 to 90 days. I’d try to bake a lot, and feed your starter a lot!

      Best wishes,

  6. Thank you so much, Mike! I truly appreciate your time! I have noticed that my started was smelling foul and is now not smelling foul. I see there is less bubbling this morning, but seems a bit more settled. It smells more like sour dough now and there seems to be a light liquid on top. It’s very earthy smelling, almost has a full like quality. Can I start making bread with it? And you mentioned not putting it in the refrigerator, do I ever have to refrigerate it? Is it just safe out? Thank you!!!!

    1. Hi Erica,
      The light liquid indicates the starter hasn’t been feed enough, or often enough. I prefer to weigh my ingredients because volume measurements of flour are very inconsistent. I also like to feed starters at room temeperature twice a day, more or less every 12 hours. While just feeding a starter to maintain it, I discard half, and then feed it with equal weights of flour and water, enough to double it’s size. If you have 200 grams of starter, pitch all but 100 grams and then add 50 grams of water, stir it up, and then add 50 grams of flour and stir again.

      When you are getting ready to bake, stop discarding but continue doubling the amount of starter with each feeding until you have enough to bake with. When you double the amount of starter twice a day, it doesn’t take long to accumulate enough to bake with.

      Earthy is a better smell.

      You don’t HAVE to refrigerate the starter. It is happiest when it’s at room temperature, being fed and used to make baked goods. However, even with the excitement of Covid-19 shelter in place, most folks still aren’t eating enough bread to bake every day. You can refrigerate a starter when you don’t want to deal with it. You might search for “storing a starter” in the search tool at the upper right part of the web page. There is a small text entry block and a magnifying glass there. I would rather not refrigerate a starter until it is 60 to 90 days old.

      Best wishes,

      1. You’re so kind! Thank you for taking the time to answer me. I appreciate your knowledge and patience!

        Erica 🙂

        1. Hello Aisha,

          Ideally, we wouldn’t refrigerate our starters at all. A happy starter is a starter that is fed and used often. However, with smaller family sizes and changing diets, most of us can’t really bake every day. So refrigeration is a reasonable approach.

          However, it takes 30 to 60 to 90 days for a starter to mature, to become as strong and flavorful as it can. When refrigerated, the starter doesn’t improve – in fact it declines.

          I discuss this at some length in the “Storing a Starter” page.

          Best wishes,

  7. Also, do I keep discarding? I started with an organic rye and water. I’ve been discarding and saving 113g and adding 1 cup of ap flour and 1/2 cool water.

    Thank you!!!

    1. Hi Erica,
      You might search for “feeding a starter” or “maintaining a starter” using the search tool in the upper right hand corner of the web site. There is a text entry box and a magnifying glass.

      There are two likely outcomes if you don’t discard. If you keep feeding your starter the same amount of flour and water, you’ll starve it. A fully grown dog wants to eat more than a puppy.

      Or, you can keep doubling the size of the starter. The down side here is that if you start with a teaspoon of starter and double it twice a day, in 10 days you’ll have enough to fill a swimming pool. And 12 hours later you’ll have a very upset neighbor. Discarding seems wasteful, but it is less wasteful than not discarding.

      Best wishes,

  8. Also, one more thing … at what point do I stop feeding it daily? Right now I’m on twice a day. I’m at day 7 today. I’m not sure I should feed it twice any more. Sadly I found this page after selecting the recipe for starter I chose.

    Thank you!! 🙂

    1. Hi Erica,
      At what point should you stop feeding your children? Once they bring home a good report card?

      Your starter is alive, and like all living things it needs to be fed. I recommend feeding twice a day as long as it at room temperature. You might look for “maintaining a starter” in the search box.

      You might also try searching for “Storing a starter” in the search bar in the upper right part of the web site. It’s the text entry box with the word “Search” in it and a magnifying glass icon on the left side of the box.

      Best wishes,

  9. Apologies if this was already covered, I didn’t have time to read all the comments. First, THANK YOU SO MUCH for such an informative post!! This made me feel so much better. I’ve been trying to start a starter all quarantine (I know I know, just like everyone else!) and I’ve had to scrap three. I’m hoping this fourth is “the one” but I’m nervous. I had that huge burst of activity on day 2 and then just blah, almost no rise since, and a strong (but not very strong, and not unpleasant) acetic acid smell still now on day 6. Your post put me at ease as far as smell (although I’m still convinced it should smell like yogurt), but I’m concerned about consistency. It’s very thin (even though it’s quite thick right after a feeding) and not very fluffy (although it does indeed have bubbles). I’m so insecure about this!! Any encouragement to give? I’m using rye and bread flour, just FYI.

    1. Hi Ashley,
      It alwauys makes me scratch my beard when someone says they don’t have time to read and then ask me to write something. Anyway….

      I’ve never had a sourdough starter that smells like yogurt. Even one that I started with a bit of yogurt. (That was to make Katrine Kirk’s Rugbroed, which is a delightful bread.) Normally, I say all you need is flour and water. (And the Beatles would add Love, but that;s not for sourdough.)

      Slumps are not uncommon when starting sourdoughs. The keys are to trust the process, to feed twice a day, to keep the starter at a reasonable room temperature, and to feed it enough to double its size with each feeding. Some people call that a 2:1:1 feeding, or 2 parts starter, 1 part water and 1 part flour. Some people prefer a more generous feeding, such as 1:1:1 or 1:5:5. Feeding more tends to get the yeast working very well, and extends the peak rise time. 2:1:1 works for me, but it’s not carved in stone. Feel free to feed more aggressively, but remember to discard before you feed.

      Best wishes,

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  11. Hi Mike,

    I think I must have read each of your pages at least 5 times over this past month!

    I have tried to rescue my original starter after reading Your pages as it was producing way too much alcohol (I forgot to feed it once 🙁 ). I took 5% of the original and have been feeding my new one twice a day with just white flour now for 3 days. Whilst it doesn’t smell like alcohol when I open the lid (like my last one did) and I’m not getting a layer of alcohol liquid, if I smell it real close up it does have a slight acetone/alcohol smell. It bubbles well after each feed, doesn’t double but I would say increases by 50% and then drops by the time it’s ready for another feed.

    Reckon I should just give up and start over? My husband is laughing at the amount of flour I’ve used this past month and the fact that I still haven’t baked a loaf of bread! To save him teasing me further I was thinking maybe I should just start over instead of waiting to day 7 to give up on this one too.

    Thank you!

    1. Hi Sacha,
      Not feeding a starter once isn’t really a problem. Have you ever missed a meal? I’m sure you have. Did you die or become ill as a result? Since you’re able to send me messages, I’m fairly sure death didn’t follow. When a healthy person misses a meal, no real problem results. Same with a sourdough starter. If you normally take good care of your starter, missing a feeding won’t really be a problem.

      As your starter digests the flour, the yeast will produce alcohol and carbon dioxide. It’s what yeast does. It also creates many flavor compounds. An alcohol aroma isn’t unusual. Acetone isn’t uncommon either. However, acetone can be a sign that there problems. If it’s a mild acetone smell, just feed your starter. If it’s a strong acetone smell, you might look at our article on “Reviving A Healthy Storage Starter” and scroll down to the section that starts, “The Ugly Tale of the Long Neglected Starter”.

      Sadly, my crystal ball broke a while back, so I have no real idea of what you are doing. I wore the poor thing out doing computer support. You say you are feeding the starter twice a day. Great! That’s a good start! However, it isn’t clear how much you are feeding it. I prefer to feed my starter enough to double its weight each time I feed it. Some would call that a 2:1:1 feeding, or 2 parts starter, 1 part flour and 1 part water by weight. Some feed more. When my starters are sluggish, I’ll feed them enough to triple their weight, or 1:1:1. When you feed a starter enough to double, or triple, it’s weight twice a day it gets very large, very fast. If you start with a teaspoon full, it is enough to fill a swimming pool in 10 days. And a second swimming pool 12 hours later.

      That’s a lot of flour, and a lot of stirring. So, I discard 1/2 or 2/3 of the starter before feeding it to keep the amount of starter under control. When your starter is healthy, you can set aside the discarded starter and use it for other projects. If it is fresh, you can bake with it. When it’s a few days old, you can look at our Discarded Starter recipes. If you feed the starter the same amount each time you feed it without discarding some in short order you will be underfeeding it. The feeding is based on its size. Imagine you bring a Great Dane puppy home. You start feeding it 1/2 cup of food a day. That won’t be enough to help the puppy grow for long.

      At the end of a longer note than I’d started out to write, your starter is probably fine. Make sure you are feeding it twice a day, as I’ve outlined above. If it is still sluggish, go to the higher feeding rate for a few days.

      Good luck,

  12. Hi

    I see a cheesy smell was discussed…. Do you think that’s similar to a pastey smell? I don’t think it smells as bad as cheese or rotten, but it did get pastey and didn’t seem to go back to sour or acidic. This was after I left it in the fridge for 5 days and brought it back to room temp and fed. I kept it going for several days (a week?) and used it and didn’t make anyone sick, but I couldn’t get the thought out if my head that it might be off and didn’t like the results.
    (However my flour brand changed around the same time.)
    I ended up tossing and starting a new starter, but I’m worried I might have that kind of change again. (My new started is 10 days old and ok.)
    Have you dealt with a pasty smell and have any advice? Thank you so very much for your site and feedback!

    1. Hi Lynn,
      Since you discarded the old starter, this is all academic.

      Describing smells is not easy, and is always in comparisons, like wine tastings. And in wine tastings one person says they taste hints of cherries, while another says fresh berries. And even that is vague given the myriad strains of cherries and berries in the world. All of which is to say, what’s pastey? I’m thinking something like library paste, which is just flour and water. If a starter keeps smelling like that, it is fair to think that nothing is happening. When the starter changes, that’s a sign that something is happening.

      My own view is there there is no reason to wait until a starter warms up to feed it. It’s cold and hungry. Adding water (even room temperature water) and flour (even room temperature flour) will warm the starter and feed it. It isn’t clear how often you fed it over the week.

      We have an article on reviving a starter, and there is a special section in there on reviving a long neglected starter.

      And, to keep the problem from arising again, we have an article on maintaining a starter as a part of our sourdough starter primer.

      Good luck,

      1. Thank you!
        Yes, it’s academic, and I wasn’t very descriptive…. The smell was like a mix of old school white paste (glue) and playdough. (I don’t like the smell of play-doh, but some people do)
        I was at my mom’s for 5 days so it was unfed. (I split it and took some with me… And then left that with my mom. The other jar was in the fridge at home.) It’s helpful to know not to rewarm. I’ll check out your starter maintenance links. I’ve read so many variations on what people recommend, but it makes sense to feed it cold. Thanks again!

        1. Hi! I have a question about my starter. I started it in a mason jar, feeding once a day, half white, half wheat flour at the 1:1:1 ratio that is commonly recommended. I read enough to understand to be patient and expect mysterious changes before a consistent product is achieved.

          However around week 2 I started getting a strong acetone smell. Even though I was feeding daily, I tried increasing my feeding ratio, as many suggested the smell meant my starter was “starving”. I did not see any improvement.

          Somewhere else I got the impression that the plastic lid I had on my jar, just barely cracked, was maybe not letting enough air in to let my microbes breathe. I took it off, and replaced it with doubled coffee filters and a rubber band, and I saw great results! No more acetone smell and much better rise, even the the doubling point!

          Confident now, I started stepping up my feed ratio, because I saw somewhere that I should feed my starter enough that it has just peaked by the next feeding. I got close to 1:8:8 or 1:10:10, if I recall. I used a new clean jar at every feed.

          Then, one morning, I opened my jar, and did not notice immediately notice anything off, but as soon as I stirred it up, it smelled distinctly — and disappointingly — of farts. I kept feeding a couple of days more, but my rise between feedings decreased noticably, and every morning… more farts.

          I have read all I can find on farty starter, and seen everything from “it’s contaminated, trash it immediately”, to “it’s hot weather, mine smells like that every summer.” I DO live in the southeastern U.S., and my house this time of year is a humid 76 – 80° F during the day, but I also know things are going wrong because my rise has decreased to about 50%, max. This is not a healthy smell.

          I stuck this thing in the fridge in exasperation after my last feeding several days ago.

          What do you think? Any guess on what caused the microbe shift (too much playing around with feed ratios, maybe)? Is there any way to remediate a farty starter, or should I scrap it and start over? How could I avoid it happening again? I am about 4 weeks into this experiment, and all I’ve done so far is a single batch of discard pancakes, made in that brief, magical window after the acetone had cleared up and before the farts set in… They were delicious. I am sad. -__-

          Thanks for any suggestions you might have.

          1. Hi Katy,

            Your email is filled with, “I read somewhere” and “I heard” and “someone told me”. Before we redid the web site I had an article about picking one guru and sticking with them, and avoiding Google and social media. The problem you are facing is when you ask 4 bakers you will get 10 opinions. And whatever you ask, you’ll be told, “Oh, that can’t work!” “Oh, that can’t work” is code for, “I don’t do it that way! And I don’t think Hank did it this a way!“. So, my suggestion is to pick one guru and stick with them until you get a starter that works or you realize that it isn’t going to work for you. I tend to prefer online resources that answer questions. The three ways of starting a starter here have all been battle tested and refined by input from people who had trouble with the process or places where we could have been more clear on the instructions.

            I’d start with the “Starting a Starter” tutorial. Some people are upset that introduction doesn’t tell you how to start a starter. Nope, it is an overview of what is happening when you start a starter by any method. Some people don’t like all that reading. It takes about 5 or 10 minutes to read, but since it will take a week or so to start a starter, it’s a small investment. Especially if it keeps you from going down the wrong rabbit hole and wasting a month or more, as some people have done. From that article, you can to to any of three ways to start a starter. Once you are able to start and maintain a starter, and to make bread with the starter, you’ll have a better idea of what works and what doesn’t, and be ready to look for more teachers.

            One of my mantas as a systems engineer is that it takes a consistent process to create a consistent product. And consistency is what is missing in your description. Some specific comments…

            Sourdough cultures are what is called facultative anaerobic organism which means that it can use oxygen but doesn’t need it. On short, there is no reason to leave a sourdough culture – at any stage of development – exposed to air. We cover that in the Starting a Starter article.

            When a starter is at room temperature, my experience suggests it should be fed twice a day. If you feed it less, it can get into trouble.

            With regards to the starter you have put into the fridge, I’d probably revive it. Most starter problems can be resolved by feeding the starter. Regularly. And by weight, not volume. We have an article on Reviving A Starter in the Sourdough Tutorial. Scroll down to the section on “Reviving a Long Neglected Starter”.

            Hope this helps,

  13. Hi – Your article has been so helpful! I have a whole wheat sourdough starter that’s a couple months old that I left in the fridge for a few weeks without feeding it. Brought it out on the counter, did a feed, but forgot to put it back in the fridge right away and went out of town for a few days. We turned the air conditioning off and our house got up to around 28C/82F… not enough to kill the yeast I think. Anyways, once we got home I shoved it back in the fridge. A week later, I bring out the starter with its dark layer of hooch on top and it smells so rank…. to me, it smells like a baby’s poopy diaper. Perhaps this is the wino’s vomit you speak of. It has never smelled like this before.

    Have you ever come across a smell like that? There was no visible signs of mold. I’m now on my 3rd day of feeding it to try and revive it (2nd day of feeding 2x/day). It is bubbling but not rising. I’m going to take your suggestion of using a fresh clean jar for my next feeding. Any other suggestions? At what point do I just start over?

    1. Hi Morgan,
      A starter is kinda like a pet or a child. While more resilient than some pets or kids, it does need to be fed fairly regularly. I like to be sure it is active and happy before I refrigerate it. Refrigerating it doesn’t stop the biological activity, just slows it. As anyone who has had food spoil in a fridge can attest.

      I’ve smelled that smell, and think you’re probably still OK. I’d suggest the instructions in the “Reviving a Sourdough Starter” post, and I’d probably to to the 3 time a day feeding where each feeding will triple the size of the starter, or to 50 grams of starter add 50 grams of 2ater and then 50 grams of flour. Some people call this a 1:1:1 ratio.

      Then you might look at the article on “Storing a Starter“.

      Good luck,

  14. Hi Mike!

    I have an established sourdough starter that’s about 3 months old made from rye and bread flour at 100% hydration. I’ve tried to make bread with it 3 times and the bread has turned out under-proofed each time. I think its been a starter issue so wanted to spend some time strengthening my starter and started to realize my starter has been starting to smell terrible (vomit + dirty socks?)! It actually smells similar to to day 2-3 of new a starter. While “strengthening,” I’ve fed it two-three times daily with half rye and half bread flour for 3 days at 80-85 degrees but the smell hasn’t improved. It does double and almost triple in size. But just wondering if you had any advice or tips!

    Thank you so much!

    1. Hi Aisha,
      I find I get the best results when reviving a starter to only use a white flour. When you add rye or whole wheat flour you add a lot of stray microorganisms with each feeding. By using only white flour you are more feeding the existing strains of bacteria and yeast and allowing them to strengthen.

      So, try a few feedings with just white flour and water and see what happens.


      PS – if the starter doesn’t improve in a few days, you may want to start a new starter. Professor Calvel’s method lets you get a new starter in 2 1/2 days! -M

      1. Hi Mike!

        Following up on your recommendation:
        I started feeding my starter with bread flour and water for 3 days as per your recs. The smell is definitely less potent, it’s slightly present still when I mix around the starter. Also, noted the starter isn’t as active anymore; it rises less than double after 12 hours. I’ve done the float test on it, and it has been floating though. That being said, just wondering if you think I should go ahead and start a new starter or keep working on this one.

        Thank you so much!!

  15. Hi Mike,
    I’m new to all this, but very excited about the overall process. I’ve already baked numerous loaves of sourdough ‘look’ bread. I’m at the day3 mark of my starter and am already noticing that vinegary odour which appears to be normal according to what I’ve read here. I’m only feeding once a day though. The plan is to refrigerate the starter at some point. Could I ask how often I will need to feed the starter once it resides in the fridge? I’m reading conflicting posts on this subject. Regs, Paul

    1. Hi Paul,
      I strongly recommend feeding a room temperature starter twice a day. Feeding it less tends to starve it.

      As to refrigeration, I like to wait until a starter is 30 to 90 days old before doing that, as the starter is still maturing for at least 30 days and perhaps as long as 90 – though some would say even longer.

      We have a page on storing your starter you might refer to. As well as the related page on reviving your starter.

      Good luck,

      1. Thanks Mike,
        I know the answer to this will be somewhere on your site but please indulge me. If I feed twice a day while at room temperature how much starter should I be discarding each time? Assume this amount would be the same even when it finally ends up in the fridge?
        Thanks in advance, Paul

        1. Hi Paul,
          As is so often the case, it depends on what you want to do. If you are maintaining your starter, you discard enough that after you feed it you have about the same amount as you started the day with. If you are feeding your starter up for a bake, you may not discard at all.

          Let’s look at maintaining the starter a bit more. Here lately I’ve been taking 10 grams of starter and adding 30 grams each of flour and water. The starter has really responded well to the 1:3:3 feeding regimen. I’ve been saving the discard and will do something with it soon. The 1:3:3 feeding ratio is higher than I have traditionally recommended and I’ll probably talk about that in the near future in a Mike’s (more or less) Weekly Baking Tips newsletter. You may want to subscribe if you haven’t already.


          1. Hi Mike,

            Thank you. I’m hoping you can advise me. I’m new to the sourdough game, but I’ve had my first epic fail. My first two loaves went well, but my second attempt was abysmal and I’m at a loss to know why given I did the same process. Clued you advise what hydration % is optimal for baking and more importantly should I be using the starter directly in the bake or make a levain.

            I think I’m also the victim of an overload of YouTube info. I’d be grateful fir your advice here in terms of starter and/or levain quantities I should be using for an average loaf.

            My latest attempt has my dough very sticky and unworkable for shaping with very little bulk rise happening.

            Thank you in advance.
            Regs Paul

          2. Hi Paul,
            Getting started with sourdough can be frustrating. Sadly social media and YouTube remind us of the adage about a man with two clocks never knowing what time it is. many bakers, especially new bakers, want one solid concrete answer. What hydration should I be using? How much starter should I use? What is the meaning of life, the universe and everything? Sadly, I won’t be telling you 42.

            Once you understand sourdough, the conflicting advice makes more sense as you understand that the different people have different approaches and can often say, “Oh, that’s why s/he does that!” Still, it can be frustrating to ask a question online and see you’ve triggered a veritable avalanche of contradictory suggestions with the various authors telling each other,”No, that won’t work!”

            Worse, everything is connected. What worked for me in the mountains of Colorado is less successful in the lowlands of Texas. Here are some basic ideas….

            The point of a levain is to make sure you have an active starter. Some people maintain a tub of starter and use some of that to create a levain. Whether you get there by taking some of your starter and feeding it apart from the rest of your starter, or just feeding up your starter in the tub really doesn’t matter all that much, however, as you keep using a starter it matures and gains in strength. When you feed a levain and use it all up, the main starter has not developed, so there is some advantage – at least with a young starter – to just using and maintaining a tub of starter.

            What matters is that you have an active starter. When you feed a starter it stalls for a bit and then rises. It reaches a peak, and then begins to recede. I like to use my starter at, or just after, the peak. If you let the starter fall, it will be very acidic and cause problems with the gluten structure of the bread and create a sticky all too loose a dough. My long standing guideline is that I never trust a starter that can’t double in size between feedings or which is less than a week old.

            How long does it take for your starter to reach its peak? It all depends. On your starter. On how you feed it. On the temperature of the starter. On the flour you are using. The hydration of the starter. The best bet is to watch your starter to see how long it takes to rise, and how long it stays at a peak. You don’t have to sit there for 12 hours… just come back and check it out from time to time. I should be posting some time lapse videos of my starter rising and falling later this week which will help you see what to look for.

            How much starter to use is another great question. Once again, there’s no single answer that works for every bread. No “42”. Some of my breads use as little as 5% starter, others as much as 40%. These numbers are in baker’s percentages. Why the range? It depends on the results I want. More starter will yield more rise. Less starter, often yields less rise. Less starter also means a longer rise, which leads to a more sour bread. Sourness is the product of fermentation, with longer fermentatino resulting in a more sour bread. I don’t want that much sour in my cinnamon-raisin-sourdough bread, so more starter gives me a faster rise and less sour. The same is true of the sourdough flax seed bread. Sp. what does that mean to the baker? Give it a try. Taste the bread. Adjust as needed to make the bread become the bread you wanted to make.

            Hope this helps,

    1. Hi Fannie,
      Sadly my crystal ball burned out some time ago so I have no idea what stage you are at with your starter. Is this a brand new starter that hasn’t taken off yet? Is this an older starter that has failed?

      If you are starting a starter and it isn’t doing what you want, I’ll suggest you try the Starter, Mike’s Way page. It isn;t the fastest way, but it is very reliable.

      If your starter used to work, but isn’t now, I’ll suggest you look at the “Reviving a Starter” page.


  16. hello again Mike,
    as always great advice, thank you. As you say we all need to work out our own methods, ratios, percentages to see what works best for you. What I have learned in this journey so far is that you can overload yourself with too much info (YouTube overload) which in my case resulted in confusion and a few fails. I’ve started making notes for each bake I do, tweaking things a little until I’m 100% happy. As mentioned I had 2 recent EPIC fails which made me get back to basics and keep things SIMPLE. The following for me resulted in the best loaf so far. I’m going to bake another loaf soon to re test the percentages,

    I’ll also take your advice and skip the levain and use the starter which I still keep at an ambient temperature as you advised me given it’s less than 30days old.

    Flour, white 400g
    230mls, tepid water (33c) 57.5% hydration
    185g of levain (starter) 46%
    5g of salt 1.25%

    1. Hey Paul –
      Please let me know how things work out. If they work out well, great – we can take a victory lap together!
      If it isn’t ready for prime time, that isn’t defeat, just a sign we need to work on things a bit more!
      Best wishes,

  17. Hi Mike,
    It went well, but…what I’m noticing is that in some cases the more I work (knead) the dough the stickier it becomes. I tend to stop at that point fearful of it becoming unworkable, not really wanting to keep adding flour. Have you experienced this phenomena?

    I use my stand mixer fir the first 5minutes or so, then knead by hand after that. P

    1. Hi Paul,
      Not knowing what formula you are using, not to mention what flour or the condition of your starter, I’m not sure I can give you solid advice.

      Some thoughts – if your mixer is doing its job, you shouldn’t need to knead it further. When I use a mixer, I give the dough 5 minutes of kneading, a 5 minute rest, and then 5 more minutes of kneading. With stiff doughs like some pizza doughs or bagels I give it 10 minutes of mixing the second time around.

      When people are having troubles, I always suggest going back to the basics. Try a yeast based recipe to see if you are having sourdough issues. If that turns out well, you might aggressively refresh your starter, or create a new one.

      Instead of using a mixer, you might try the stretch and fold technique. There are many stretch and fold techniques, this is just one of them. I should do a page on some other ones. Maybe with a video. For now, you can google coil fold. Stretch and fold makes it easier to handle sticky dough.

      A few things I’ve learned about handling sticky dough. One person’s sticky dough is another’s just right dough, it’s a matter of learning how to handle it. I don’t want my dough completely un-sticky, to paraphrase a country western song, “I like my dough on the tacky side!” It should be more interested in sticking to itself than to you or your work surface.

      Using a fast, light touch minimizes sticking issues. In a worst case, wet hands can reduce sticking also.

      Good luck,

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