August 2, 2023 - 6:34pm
Making a starter when you're dealing with mold?
I've been trying to make a starter for several weeks now. I've tried and failed many times. The first couple of days go fine and then the starter just dies. After the last time, I just gave up and left the container alone with the lid sealed. It's an airtight seal, so whatever is in the container was in the container when it was last fed. After several days, I noticed an explosion of mold, both white, grey and billowy. That explains the failures.
Now what? Don't say mold remediation. I get that. However, is there anything I can do to get it to work? Should I just give up until the mold problem can be rectified?
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Hi Mark,
I recommend you familiarize yourself with what's going on in the starter at the micro level. It is very well explained by Debra Wink in two parts. It is common for a new starter to look dormant after a few days - but it's not. Part 2 has the actual process. Part 1 has theory and background. Well worth the read.
The Pineapple Juice Solution, Part 1 | The Fresh Loaf
The Pineapple Juice Solution, Part 2 | The Fresh Loaf
Cheers,
Gavin
After you read Debra Winks' series, you may come to think that what you see is not actually mold, but the scum from some intermediate organisms. Scoop it off and keep going, and even better add some pineapple juice or other acidifier and see if you end up with a usable starter in a few more days.
I'm betting you will.
TomP
I just put up a method for making a starter in another thread - try that. Enjoy!
I'm pretty sure it's mold.
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I've never seen that amount of mold in just a few days. Mystery I think!
I once did the same. Covered the jar and let it sit for ten days in a closed cupboard in our kitchen. Ten days later, there was mold on the surface and ready to use starter underneath it. I removed the mold, refreshed the starter and baked a perfect loaf of bread with it.
Mold is what you can see, these are visible microorganisms, sourdough yeasts and fungi. Underneath it, you can be sure that invisible sourdough microorganisms grew as abundantly inside the dough. Just refresh it with flour and water and you will see and smell them
To prevent mold growth on the surface, use the dry barrier method. Either sprinkle a thick layer of flour on the surface of your starter, if it is liquid or soft, or bury the ball of stiff starter in a bag of flour.
While molds are not the death knell of anything it is found growing on, ignorance of what kind of mold you have can get you sick or worse. Mold is one of many types of fungus and its mycelium can reach several centimeters into whatever it has infected.
Best to clean and start over using the techniques Marianna suggests, or just avoid letting it sit for a week unattended.
I agree.
Those molds don't look like typical yeasts and fungi from the flour, more like from hands and kitchen environment: dish rags, surfaces and bioaerosol.
It is better to start from scratch if you want to use the one step method of preparing a starter when the mixture is left for 5-10days unattended. Normally, frequent refreshments and stirring in between prevent the mold growth on the surface of a starter.
Mold from hands, from the surface of a laptop
Typical yeasts and fungi from medium rye flour, what grows in 5 days at optimal temperature in a sterile Petri dish. Pink is sourdough yeast, white is bakers yeast, green and fuzzy white is mold. You can see that medium rye flour (most but not all of the bran removed) is not that moldy, there are more yeasts than other fungi in it.
Does the fact that the container was closed have any effect on the mold growth? Are molds more aerobic or anaerobic?
Or, were the good microbes negatively affected by the lack of air and unable to compete with the molds?
Molds are aerobic. Actually removing oxygen is one of the ways to prevent their growth. But simply closing a lid doesn't really create an anaerobic environment, just leaves a finite amount of oxygen... Is the lid truly is airtight. A better way is it cover the surface directly with a plastic film, for example, and remove access to the atmosphere completely.
Molds are obligate aerobes, they need oxygen to survive. However, mold grows even at very low concentrations of oxygen which makes it difficult to fight mold growth by limiting oxygen. Blocking access to both moisture and air simultaneously is the best way.
There was a lot of air in that closed jar, enough for the mold to grow, obviously.
Yeasts, on the other hand, are facultative aerobes. They proliferate fairly well inside starters and bread dough where all oxygen is consumed within the first 10 min after mixing them. So, no, neither sourdough yeasts nor sourdough bacteria were very negatively affected. They were affected (slowed down) but not stopped.
What would stop the molds eventually is the alcohol released by the yeasts into the starter and eventually into the hooch on which the mold grew in Mark's case. Once it becomes too alcoholic, it becomes toxic for mold (and for yeasts as well).
I have never read about molds competing with sourdough microorganisms in scientific literature, so I do not think that Mark should blame mold for the starter's failure to thrive. I only heard from the bread scientists that mold growth on starters is rather common and to be expected because the spores are in the flour and especially on malted grain/milled diastatic malt and acidity does not affect them, and either continuous stirring of liquid starters or dry flour barrier on soft and stiff starters are the ways to combat it.
Thank you! Very informative.
Oxygenating the must prior to fermentation benefits the yeasts. Without oxygen yeast might struggle at the start of fermentation. However i'm not sure how this would translate to bread.
Abe, bakers also oxygenate flour and dough at the start of fermentation. We call it sifting flour and kneading dough : ) Both procedures introduce oxygen, so much of it, in fact, that the volume of the dough increases up to 10% by the end of kneading, all due to the air trapped inside the dough as it is being kneaded.
One of my students did an experiment once, she baked two loaves from the same flour in the same bread machine, but one loaf was from sifted flour and another - from unsifted. The kneading time was obviously the same and everything was measured in grams and with 0.1 g precision (yeast/salt). The "sifted" loaf one was 20% taller.
Oxygen both stimulates yeast and makes gluten stronger, that is why in commercial baking flours are sifted thoroughly prior to mixing to improve the efficacy of the process and improve the output. Commercial flour sifters make flour go through the set of 30 sieves! I rarely sift flour at home, I mostly focus on kneading, but when I do sift, I see how each additional pass through the sieve magically transforms the flour, it looks and feels like a completely different substance then.
It's easy to forget that there are two phases involved. When we are developing a starter, we want to increase the number of yeast cells in the starter. That requires the yeast to reproduce. To do that they need to be in an environment that supplies oxygen to them. They will also produce some CO2, but not so much.
To cause rising, the yeast cells need to be in an anaerobic environment - that is, free from air (and so free from oxygen). Then they will produce alcohol and lots of CO2.
The reason I have suggested stirring the nascent starter from time to time is to keep introducing air into the mixture, so as to promote yeast reproduction. So a vigorous stirring that whips in some air should be better than a gentle one from the point of view of encouraging yeast reproduction.
I have never tried to compare sifted vs non-sifted flour, but I once tried to aerate the water using an immersion blender. When I fed my (well-established) starter, I split it into two parts and blended the water for one. Then I measured the volumes over the next several hours. The blended one rose faster than the unblended one. The difference was around 15% or so (graph attached) below.
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Slap and Folds. With these gentle stretch and folds, one so often associates with sourdough, one forgets that kneading actually is there to introduce oxygen too. Perhaps slap and folds, and handling the dough without mittens, is what's needed for a good dough at the end of the day. Thank you for that Mariana, your explanation, experimentation and graph really show how important it is. Nowadays people tend not to sift four thinking it's old fashioned. If sifting flour alone made such a difference then using the two fold approach would really be the way.
P.s. I misworded it before... meant to say not sure how it translates into propagating yeasts when making a starter. I always believed that introducing oxygen was very beneficial with vigorous stirring. And more recently undertsood the importance when making wine/alcohol. Just wasn't sure how the two processes and the reasoning behind them cross over.
Ewwweeeuuuuu! You win, Mark. It’s mold.
Have you tried sterilizing the container you use when beginning the starter?
I think the previous posters were right, starters do like to play dead for a while, but if you keep feeding it on time, it will probably wake up and grow.
Mold spores are everywhere so it is not unusual to have mold develop in a closed, room temp humid environment with semi-digested starches. Back to your starter...
First of all, thoroughly wash your container AND YOUR HANDS before you start your new starter. We are always covered in mold spores and other bacteria as we live and go through our day and would be even if we lived in a sterile lab environment. That being said, our hands play a significant role in molding and spoilage of wrapped products if we handle them in the course of using them. If I take slices of bread out of a wrapper (commercial or homemade) I try not to touch anything but what I take out. I have observed that homemade bread more often than not stales before it will mold if I make an effort not to touch it when I slice. I use a clean towel or the plastic wrap between my hand and the bread. I have observed it makes a big difference.
Starting a starter does have some idiosyncrasies that can be puzzling and can take more than a week or so. Refer to the links provided, use the search box and be very, very patient. Starters go from no activity to some bubbles to lots of bubbles to almost no activity and few bubbles to steady activity. As it goes through these stages a LOT is going on at the micro level. Keep going when it gets to the quiet stage. Some "tenants" are "moving out" and new are moving in, now that the environment is more suited to them.
You have a bit of a learning curve ahead of you. Keep looking for answers and asking quiestions but a lot of those answers are on this site. Use the SEARCH box, look at the links on the site and wash your hands before working with the starter.
Start over and sanitize your container, lid, utensils etc you intend to use. You can do this using bleach mixed with water to rinse and then let air dry. I think it's a tsp of bleach to 1/2 gallon of water, but don't quote me on that. CDC says:4 teaspoons of bleach per quart of room temperature water
When you get ready to start again, look up the Pineapple juice starter. It's on here and it's what I used to get mine started after failed attempts. Turns out my water has both chlorine and chloramine in it and both are bad for yeasts (and fish). Chlorine can just be left out to evaporate, but the other one doesn't evaporate. So for feedings I use bottled water with minerals added (Dasani) and bake with my normal filtered water. I left my starter out in the beginning, but once it got going I started keeping my starter in the refrigerator (not the freezer).
Or you could use boiling water. I have never actually sanitized any of my baking equipment - a good soaping and a good flushing rinse or just a good rise is all - but then I never had an issue with such visible mold.
It's pretty common to keep the starter in the refrigerator between uses and feedings, and I do it too.
But from the photos, and my experience in making starters, it definitely looks like it's been contaminated. Never seen mould like this in a starter and even when I have, through neglect, it's never looked anything like that. I'd definitely either sanitise everything! Or throw the container away and use something else and still sanitise everything that will be used when making the starter. And for good measure use the pineapple method too. Perhaps even new flour.
I wish I could chime in intelligently but I am in the same position as OP except mine has no colors. Same deal after the first feeding this stuff starts popping up. I don't mean to hijack the thread, but rather than start a new thread - can I quickly ask: what about mine
Could be kahm yeast. Might be some other kind of yeast overgrowth. Doesn't look too unhealthy TBH. If a starter looks like that it's worth trying to save.
Get a new container. Sanitize it. Carefully skim the top of your starter and take some of the healthier starter from underneath. Transfer to the new container and carry on.
What method are you following? Might give a few clues as to what went on.
50g king arthur wheat flour, 50g king arthur bread flour, 100g RO water (boiled & cooled). That was a brand new container, cleaned. That is the second try. Both this and the first try made it through the first feeding after a nice growth spurt a day and a half after starting. Pulled a couple tbsp off and added the same flour & water mixture as above. Didn't get a nice growth spurt (on both attempts) and a day & half after first feeding I start to see the white stuff just like this attempt. I home brew so I usually have the sanitizing thing down pretty well, but this is clobbering be. Same exact outcome after the same process at the same time. And they don't stink.
I started a new batch in a glass container this morning and just siphoned the crud off of this and started a second starter in another glass jar a few minutes ago.
Wow, just read the pineapple links and will try that too.
My starter went wrong and developed a foul smell. There wasn’t any visible mould but I noticed that the water filter I had been using had green algal type mould around the spout. I started again from scratch and now only use tap water or bottled mineral water. Not had the problem since.
Dealing with mold can be frustrating, but there are a few things we can try to salvage your starter.
To begin with, let's make sure we're using a clean container and utensils when feeding the starter. This will help prevent any mold spores from contaminating the mixture.
Next, consider adjusting the feeding schedule. Sometimes, starters need more or less frequent feedings depending on the environment and temperature. Experiment with different feeding intervals to find the sweet spot for your particular situation.
Another tip is to adjust the hydration level. A drier or wetter starter can sometimes discourage mold growth, so play around with the water-to-flour ratio.
Also, keep an eye on the temperature. Extreme temperatures can impact the development of the starter. Finding a warm, consistent spot for it can make a big difference.
If the mold problem persists, you can try using organic, unbleached flour, as it might contain fewer mold spores than regular flour.
I had issues of mold my first two tries. I read the pineapple link at the top of this thread. I thought it was the craziest thing, but I tried it. The first several days nothing happened, but then wow. Still too early to bake anything with it, but next week I should be good.
Debra Wink's pineapple juice approach is based on valid science. Brilliant!
Cheers,
Gavin
You think that's crazy, imagine coming home to a message from the LA Times asking for an interview. I thought I was being punked. But it was for real :)
Scaling Mt. Sourdough - Los Angeles Times (latimes.com)
The article was published January 30, 2008 in print and online (I don't know why the date is different now). And over the next few months Ms. Scattergood's article was picked up by several other publications around the country, each giving it their own title.
Enjoy your new starter :)
dw
I'm going to try the citric acid method described in the pineapple juice link. None of us in this house enjoy pineapple all that much and I'm loath to waste food. I can get food grade citric acid on Amazon easily enough and 1/2 teaspoon per 120 grams flour is a simple formula to follow. I'll probably get pH test strips too...
Hi Mark,
What you want is ascorbic acid (vitamin C). Citric acid (sour salt) is too strong --- 1/2 tsp will probably stop everything. It's actually a pretty effective preservative :) If you've already ordered it, just use a tiny pinch.
My best,
dw
🥺😬 Good catch! Thank you!
Just curious…does the ascorbic acid participate in any other way (e.g., redox properties) than just as an acidulant?
For this use, the process proceeds in the same time and pattern as when it occasionally proceeds naturally without the initial burst of activity. In other words, "by the book." I'm not saying it's other properties don't exist when using as an acidulant, only that they don't appear to matter for this application as evidenced by side-by-side results.
According to this page:
https://www.chainbaker.com/vitamin-c/
"Using ascorbic acid can strengthen the gluten structure of bread dough enabling it to trap more fermentation gas inside it and gain more volume. It is a cost-effective way of producing larger loaves.
Bread made with ascorbic acid will have a finer, more tightly packed crumb with a very soft texture"
And
"A very small amount is required. It is advised that 20mg – 30mg per 1kg of flour is enough. That is 0.02g – 0.03g. Most scales will not even register such a small amount. Saying that, I tried using 20mg per 1kg and it did not make a difference, so I ended up using 40mg per 1kg and that worked well.
When it comes to fresh lemon juice it contains around 50mg of vitamin C per 100g juice, so that makes it quite easy to calculate the required amount for a recipe."
Never tried it myself, but I have seen it listed as an ingredient in a few flours.
Yes, ascorbic acid is a dough oxidizer, but how? This seems to be a contradictory function of ascorbic acid. In virtually all applications (food, chemistry, biology), it acts as a reducing agent not an oxidizer.
I was initially puzzled by the bread literature describing ascorbic acid as an oxidizer. It is true that many compounds exhibit both reducing and oxidizing behavior. For example, hydrogen peroxide is normally thought of as a strong oxidizer, but in the presence of sodium hypochlorite (bleach), it acts as a reducing agent to produce oxygen and NaCl. But for ascorbic acid to act as an oxidizer, it must be reduced. There wasn't an obvious structure for the reduced form of ascorbic acid.
After digging around online, I discovered that the ascorbic acid is oxidized to dehydroascorbic acid in the presence of oxygen and a naturally-occurring enzyme in flour (ascorbate oxidase)—Nature provides! Dehydroascorbic acid is the actual oxidant in dough.
Here’s a more detailed explanation (with diagrams) with of how ascorbic acid acts as a dough oxidizer:
https://www.mygermantable.com/why-is-vitamin-c-ascorbic-acid-added-to-bread-dough/
Wow, good work!
I'm only going to use it to acidify the starter at the beginning of the process. I'm not planning on adding any to my breads.