The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Wild Yeast Discoloration

Angelo's picture
Angelo

Wild Yeast Discoloration

My barm has been rocking for months, fed regularly every week (8 ounces of barm to 16 ounces of bread flour and 16 ounces of water). Then a few weeks ago I notice a SLIGHT red/orange discoloration. I shrug and ignore it. Every week since there's been more. Now it's practically across the entire surface when I go to feed it!

 

What is that!?

 

 

thomaschacon75's picture
thomaschacon75

I'd throw the entire thing out. It looks like the red bacteria Serratia marcescens that colonize a shower or toilet. It often grows in standing liquids that are devoid of chlorine.

I also see what looks like a blue-purple bacteria. That scares me as well.

clazar123's picture
clazar123

http://emedicine.medscape.com/article/228495-overview

Throw down the sink- then bleach the sink. Careful not to splash! Wash hands and containers and counter as well. Start another starter.

 

Angelo's picture
Angelo

What could have caused it though? It only stays in the fridge and gets fed once a week. 

tananaBrian's picture
tananaBrian

I'd probably toss it and sanitize everything like the others have said ...it's interesting though, since in 35 years of baking with sourdough, I've never seen nor heard of such a thing.  You weren't by chance feeding it with milk were you?  Some cheese molds occur naturally and are orange in color (google Taleggio ...one of my favorite cheeses.)  If it's a cheese mold, it's edible and fine ...but who wants it in their sourdough?  Were you storing mold-ripened cheeses in your fridge at the same time as the sourdough?  Was the sourdough always covered well (tight plastic wrap cover w/pinhole to let CO2 come out)?  What does it smell like?  Taleggio can be fairly stinky and be fine, so what it smells like doesn't necessarily say much...

BTW, if you do happen to feed with milk (or milk & water) because you like the taste ...there's no reason you can't do that, but you should change your procedure a bit.  Always feed with pure natural water and white unbleached all-purpose flour ...then when you want to bake, you feed the starter with your milk (or blend) for the one recipe and do NOT put the milk-fed starter back into your mother starter ...feed it separately with water and flour to refresh it and don't blend the two.

Brian

 

clazar123's picture
clazar123

Serratia is NOT a common bacteria in the human bowel, according to a couple microbiology sources, but it IS present in the human mouth around the teeth. Interestingtingly enough, so is the famous San Franciso yeast. Makes you wonder what was used to start the original culture?

If it is serratia on your culture, simple handling with fingers can do it. I remember one site,a long time ago, gave instructions to stir the beginning starter with your fingers since humans are colonized with all the bacteria/yeast needed.It was not mentioned if the finger was well washed. I'm not so sure I'd eat in his kitchen. I'm sure we are colonized with lots of stuff-some good and some not so good to be in our food.

As tananaBrian suggested, it could be a cross contamination with something else. Very possible. I have discovered I have very few fruits and vegetables that mold/rot, since I started fermenting sauerkraut,kefir and villi(Swedish yogurt). Everything seems to ferment and smell pleasantly sour. "It" (prob some lactobacillus) is literally in the air.

Probably best to sanitize and start over.Those biggers can be persistent in the environment! Don't forget to do the mixer and any other breadpans or bowls since anything the dough was in probably would still have remnants.

 Sorry for your loss! Have fun making a new friend!

G-man's picture
G-man

When in doubt, throw it out. These are words of wisdom, especially when you're dealing with fermentation. If it isn't right, it isn't worth taking a chance that what's wrong isn't harmful. You are risking your health.

Storing a starter in the refrigerator keeps some of the organisms in the culture in a subdued, dormant state. They are simply sluggish and slow going about their normal processes, some of them very much so. As a result, other organisms that would normally be competing find the environment much more hospitable. They move in, push out the dormant "friendly" organisms, and trash the place.

This is how I've seen it explained before, anyway. I'm no microbiologist, only an enthusiast like yourself.

Angelo's picture
Angelo

I mean, crushingly sad also; I had big dinner plans this weekend to show off my sourdough recipes. Still, thanks a ton for the quick feedback and brainstorming. I wash my hands before handling bread, but I often have a few things working at once, and that's when I'm usually like "oh, I can feed my barm while I have everything out." I'm sure I must have cross contaminated something that was normally harmless ... until I gave it a few weeks in a controlled bacterial environment haha. 

 

Thanks again!

habahabanero's picture
habahabanero

If it still works don't throw it out. I agree it may have been invaded by a pigmented organism like Serratia (or Roseomonas) - less likely a mold due to the absence of fluff. Serratia is a harmless environmental organism that likes wet places ( the plug hole of your kitchen basin will do) - it doesn't usually stick around the human body long unless there is plastic it can live on or your immunity is very suppressed (it is a problem in ICU for this reason). It doesn't produce toxins or spores so once baked will be harmless and dead. So it may be worthwhile to see whether you can nurse your starter back to health.

BTW the oral cavity is dominated by Streptococci - with a few yeasts (Candida) and Lactobacilli (no particular species). Unless you're taking antibiotics it's unusual to find an organism like Serratia in your mouth.

thomaschacon75's picture
thomaschacon75

When I said Serratia, it was just a guess.

For all I know, that could be a dangerous gram negative bacteria with a rodent or pet vector that's releasing toxins into the barm, toxins that could survive baking. Also, note that there looks like more than one type of microrganism that's colonized the barm: the blue-purple colored one.

I don't think trying to save this barm is sound advice.

habahabanero's picture
habahabanero

This is getting very technical - apologies if this seems patronising or boring - I'd like to clarify things. The reason our sourdough starters consist mostly of Lactobacilli and yeast is because these are the organisms that are best able to exploit this niche - utilising flour as an energy substrate in a low pH environment at room temp. When you "train" a starter you are basically allowing these bugs to out-compete the other bugs in the mix by providing them with their "favourite" food, and discarding promotes the organisms that proliferate best in the conditions you are creating. This is the reason dangerous organisms (eg. Salmonella) don't tend to dominate, or hang around for long - they're just nowhere near as good at fermenting in a cool acidic environment. Not many bugs produce red pigment - Serratia and Roseomonas are the only familiar ones.

With regards the toxins you mentioned - I assume you mean exotoxins, toxins excreted by the bug. Very few gram negative bacteria produce these - and only in specific circumstances. Bacteria that are excellent producers of these toxins almost exclusively belong to the same morphology as our friend the lactobacillus - gram positive bacilli. Good examples are the Clostridia (botulism - botox, tetanus - tet tox), Corynebacteria (diphteria toxin), Bacillus species (B. cereus enterotoxin), and Streptomyces (most of our antibiotics!).  To survive the baking process the toxin must also be highly heat stable - Bacillus cereus and Staph. aureus enterotoxin are the only ones that are serious problem in this regard - Staph prefers high protein (ground meat or dairy) and shouldn't be present in an active starter. I suspect B. cereus could present a real problem - it typically causes a horrible 12hour gastro after eating brown rice that has been undercooked and not refrigerated overnight. - for 2 reasons - it produces spores that can survive brief spells cooking and produces a toxin that will survive reheating. Par-baked or underbaked bread could potentially pose a problem in this respect. Bacillus species are stinky bugs though - something that should put you off eating anything contaminated with them. "If it smells bad don't eat it" is very good rule to keep.

In simple terms there are really 3 types of bacteria that cause disease; firstly bugs that generally live peacefully on, in or around us and only cause illness when they get into the wrong place or our immunity is compromised (E. coli, Staph, Strep, Serratia etc.),  second bacteria we rarely come across but cause disease whenever we come into contact with them (Bubonic plague, Anthrax, Typhoid etc.) and  third bacteria (and molds) that produce toxins in certain circumstances (as above). 

Therefore for a working starter to make you ill it would either have to contain a rare but highly lethal bug that would somehow get into your system when you handle it (as they would not survive baking), or a bug that thrives in the starter and survives baking temps or produces a heat stable toxin.

Basically a long-winded explanation for why it should be fine to keep discarding and feeding - when your starter looks, smells and works like a normal starter it should be fine to keep.

 

a_pummarola's picture
a_pummarola

Yesterday afternoon I mixed some kefir water and flour, and let it sit overnight to see what would happen. When I got back today, about 24 hours after, I saw it had turned yellow and upon opening up the plastic wrap got a whiff of something awful! Truly disgusting; I can't even describe it. I've had that vomit smell while trying to culture sourdough before and this has it beat by a mile. I wonder, does anyone have any guesses on what that might have been?

I'm sure I deal with worse bacteria unseen on a daily basis but it's a bit scary nevertheless. I boiled water in the glass in the microwave and microwaved the sponge after cleaning up.

The "kefir water" is the sugary water I've got left over after fermenting for 24 hours or so with milk kefir grains. I am following some instructions on how to get sugar kefir grains out of milk grains. So far nothing (but only four days now) but the liquid smells yeasty and the pH was in the 3.5-4 range (using pH paper so it's not super accurate) so the yeast and LAB seemed to be working. I hadn't tried tasting the water yet and after this I don't think I will until the culture looks like it's stabilized in its new medium. The milk kefir from the same batch of grains tastes great and has given me no (noticeable) ill effects.

sam's picture
sam

Hello Angelo,

I noticed your container did not seem to be suitable for a lid.    You may want to use a container with a lid, but with a lid you can poke a few holes in for breathing, but not wide open.

I would throw that out.

 

jannrn's picture
jannrn

When I was in Nursing School, the Microbiology instructor gave us each an unknown to identify......Someone kept messing with mine so I had to redo it repeatedly......shortly after that, I ended up with a HORRIBLE Kidney infection.....I must have been in too big a hurry to go potty between the lab and the lecture to wash my hands BEFORE I went....anyway...it turned out to be Serratia.....NOT what I would EVER call a "Harmless Bacteria".....but I agree with everyone else....toss it and start over! Good luck!

habahabanero's picture
habahabanero

Please reread my previous post carefully Jannrn, I put a lot of effort into it. I'm not trying to be a smart@ss about it, I'm trying to clarify the science behind why people should not worry that their sourdough starter will make them sick. Fear of the unknown is a natural instinct, and a little knowledge really is a dangerous thing. If it will be less effort to make a new starter than to save a contaminated one it makes perfect sense to biff the old one, I'm with you there, but don't discard it out of fear that it will harbour some horrible highly lethal bacteria.

Deborah Wink has done a great job in furthering the science of starters, but there remains so much about them that is eye of newt and tongue of frog. Unfortunately identifying Lactobacilli, other bacteria and yeasts in starters to species level is an expensive business with no financial incentive - so it isn't done and our knowledge about them remains relatively limited. 

To return to Serratia. It, together with a really vast number of bacteria all of us come into contact with in our food and environment every day, is considered harmless ("Low virulence organisms" by microbiologists). Their ability to cause illness is heavily dependent on circumstance. A standard trick to demonstrate droplet spread of bacteria was for the tutor to rub Serratia all over the inside of his/her mouth and then walk around the classroom lecturing. Open petrie dishes were placed on the benches during the lecture and subsequently incubated to show the typical red colonies of Serratia growing the next day. However if Serratia was injected into the bloodstream it would probably be lethal in a significant percentage of cases.

Another great illustration of this point is salt rising dough. The gas-forming organism responsible for leavening the bread is Clostridium perfringens, the same organism causes lethal gas gangrene given the right set of circumstances, yet it's present in our environment in sufficient numbers to "infect" a simple flour, water and salt mixture.

Bacteria are generally beneficial.

 

 

Stuart Borken's picture
Stuart Borken

Get rid of it, it's probably the red bacteria Serratia marcescens.

jannrn's picture
jannrn

To Habahabanero, Please don't misunderstand me....and THANK YOU for going to all that trouble to explain bacteria to us. As a Surgical Nurse for almost 20 years, I am well aquainted with some of them, in that we have Staph that live quite happily on our skin, yet when it comes into conttact with the right situation, a limb for example, is lost to it. I agree that we shouldn't dump our starters out of fear and I must admit that I have done just that before. I was not poo pooing your post....not at ALL!! I guess my headache today made me quicker to jump on the fear bandwagon. Thank you again for the information and I WILL reread it and keep it to reread again as a reference tool.

Thank you!!

 

ebennett315's picture
ebennett315

I forgot my starter in my car and just was able to get it back today. It has been sitting in a closed pint container for 10 days in a relatively hot car (70-90 degrees) with no attention. The starter smells like a rotten fermenting banana and is not really THAT pungent, at least not as much as i suspected it would be when i opened the lid. The more concerning thing is that the water has separated from the dough and the liquid has a black hue to it. There is also a little bit of white strands of mold looking floating on the liquid. I tried to upload a picture but it is not working. I have read a lot of the forums with situations like this and have found @habahabanero to be the most insightful response, which is why I am debating trying to start feeding it again and salvaging is. Also, is it possible that it is just dead? There is not bubbles in it at all and looks relatively lifeless. Any response would be much appreciated. Thanks for your time.

 

 

tananaBrian's picture
tananaBrian

My experience with similar faux pas is that starters tend to form a stable and good mix of bacteria and yeast if you just give them a chance.  Before mixing, I'd scoop off anything that looks like mold (mold and bacteria are opposites ...only one or the other is dominant, not both), then stir it up really well.  Take a tablespoon of it and mix it with 50/50 rye or whole wheat flour and white flour and let it ferment until it reaches a peak and drops off a tad, then repeat doubling it until you have your desired volume back.  You can stop feeding with the whole grain (rye or wheat) after a couple of feeds when the starter looks pretty active again.  I've had to do this several times in the past (and my starter needs it right now too ...woefully neglected in the fridge!) and this process seems to work pretty well.  As for that orange stuff in the original poster's post ...All I can say is YUM!  It reminds me of my favorite cheese ...Taleggio!

 

Brian

 

 

habahabanero's picture
habahabanero

I agree with Brian, you might be able to salvage your starter by feeding a small quantity, it's worth a try. It certainly wont be unsafe. Unfortunately you may well have cooked it in the car, as the lactobacilli and yeasts probably wouldn't put up with the kind of temperatures I associate with a car in summer. I'd love to know whether you are able to resuscitate your starter. Good luck!

Dave 

 

tananaBrian's picture
tananaBrian

I forgot about car heat ...but I live in Alaska where we pray for a bit of heat in our cars!

Brian

 

hanseata's picture
hanseata

I've never seen anything like that - recently quite a few of normally very rare orange lobsters have been trapped in Maine.

Maybe there's a connection....

As a physician, I would throw it out, it looks too virulent - better safe than sorry. And even if you don't feel any ill effect from it, I doubt the bread would taste very good.

Karin