Black mould/fungi in starter - it has died


Hi lovely people, It's a while since I used this site as I've been happily making what I think is great SD for several years now. Recently I moved to a new house/studio (not there full time) and took the starter with me. It's been well behaved until about 3-4 months ago. Suddenly, just as I started having the worst hay fever I've ever had, it died. By that I mean it started smelling foul and growing black fungi/mould. The kind that grows on little 'stalks' with 'heads'. I had some dried starter stored away from other house (which I have used overseas to re-start dough and was fine) so tried twice using that to re-start it but same end result. I've now tried building about 5-6 new starters but all are ending up the same. What is going on? I'm going mad trying to work out what kind of spore/fungus is getting into the house and what it is. I suspect it is what is affecting me too. ANY help would be appreciated. Many thanks Cate

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farinam's picture
farinam 2012 December 1

Hi Cate,

Does sound a bit nasty.  If you are leaving your culture vessel open then it is possible that there are some mould spores drifting around and contaminating it.  It you are keeping it covered, then I guess the possibility is that there is something in your flour - have you tried with a new flour supply?

Perhaps try sterilising everything (containers, spoons boiling water) though I have never bothered.  Generally, starters are pretty robust once they get going so I definitely think it is something that is being introduced.  If it is something in your new abode,then a good round of 'spring cleaning' and decontamination might be in order.

This probably isn't a great help but do hope you can sort it out and get back into baking.


Cate 2012 December 2

Thanks Farinam. I'm not obsessive about house cleaning but I am clean and careful in the kitchen. I sterilize jars/ containers if I am preserving food but otherwise not. I had been feeding my starter weekly for about 3 years. When it was being fed for dough build it had its lid closed but not sealed over about a 48 hour period. Then fed again, a wait until it got active again, then sealed and into the frig for another week. I never had a problem with it and had great SD.

The very odd thing about what is happening now is the sudden appearance of this mould. I was feeding my starter at the new house and happily making bread about twice a month (I freeze it) then suddenly it started to not respond to feeding. It started by becoming sluggish, then barely responding at all, then started smelling bad, then the mould appeared. What I'm describing happened over a period of about a week with daily feeds.  

But I also find it odd that over the exact same period of time I have been constantly sneezing and have had stinging runny eyes. That says to me that there is something in the air that is not normally present. And this odd allergic reaction only seems to happen in the kitchen. I might try one last time to build a new starter in another room and see what happens.

LydEllison 2012 December 1

I think it is very unlikely that there is some special mould in your house as mould spores are simply everywhere.  It's almost impossible to determine the mould that you have from your descirption as all mould pretty much looks exactly like you describe - 'stalks with heads' are the reporoductive spores that all mould produces once it is established.  Honestly, it doesn't really matter though.  Assuming you are taking reasonable steps and using clean containers and utensils and covering during storage, I wouldn't advise anything else like deep cleaning.  It really is impossible to get rid of mould in your house.  You could reduce the number of spores in the air, but as it only takes one spore for contamination, this would be unlikely to accomplish much.  You also need to keep in mind the traditional, and very successful, use of sourdough in what by modern standards would be very unhygenic kitchens.  Most likely you used your starter less during the move and it simply became less active and basically less able to outcompete any contaminant.  I would recommend focussing on re-establishing a healthy culture.  My mother recently had a similar problem with a sluggish culture and she fixed it with cider vinegar (ideally unpasteurised).  Try adding half vinegar and half water when you feed the starter.  Mould and other contaminants are less likely to grow with a healthy, sour starter as they are inhibited by the acid.  Vinegar will be a quick cheat to get you to the same starting point.  Re-starting a culture from a dried starter is a slow and delicate process, unlike dealing with a robust mature culture, so don't be frustrated that it didn't work the first time.

Cate 2012 December 2

Thanks for your comments LydEllison. Re-establishing a healthy culture is precisely what I have been trying to do for the past 2-3 months. As I said, I have previously made new starters from dried starter without any problems. I don't find it a delicate business by the way. And I am presently totally frustrated by not getting anything I have tried to work. I have changed flour, water, containers and even tried moving the starter back to the other house. This last step resulted in a pleasant smelling 'paste' that didn't become active after 2 weeks feeding. I brought it back to the new house and within two days the mould appeared. This is with daily feeds.

As I note in my reply to the previous comment, I am convinced that my sneezing and this mould are related. The time frame is identical and the affect on me is pronounced in the kitchen. One possibility is the floor vent that is only in the kitchen. The idea is that in hot weather you open the vent and a 'whirlygig' on the roof sucks the cold air up from under the house diagonally across the room and out the roof. I only opened this vent for the first time about three months ago on some odd hot days in early spring. But it has been open on and off since then as summer drew near. 

I might try starting again in another room and closing the floor vent and see what happens. I can see the utility of cider vinegar use with an established culture but first I need a healthy culture.


More thought required...

albert z's picture
albert z 2013 January 19

i like lthe vinigar idea, think i will use it, but i will add to go with the like of braggs natural.."alive" vinigar, look it up, good to drink also for your health...



olionel 2012 December 2

is your new place a bit damp/humid etc... mould likes that sort of environment...  maybe a de-humdifier could help? Just my pennys-worth anyway...

My starter only ever smelt of feet once and I just changed to a new container and fed it with a lot of flour and water and it recovered quickly. Your problem seems a bit more persistent though,.

Hope you sort it!

davo 2012 December 3

Just to be on the safe side, it might be worth having the underfloor area that the cool air is drawn from checked out for moulds. I am far from obsessive about this kind of stuff myself, but i gather if you have particularly bad dampness you can grow some slightly nasty moulds and the spores can give you a respiratory infection. It might not be damp in the house, but if it is below, and that air is being drawn in...

Of course there may be nothing to worry about, but I would think worth at least checking out.

Cate 2012 December 3

Thanks Davo. I think this is precisely what is happening. I'm in Tas and we had a very wet winter and early spring and the underfloor area, despite big absorption trenches around the perimeter, was very wet. I'm almost certain that is where the contamination is coming from. Great pity having to close off a source of cool air over summer heat but so be it. I've closed off the vent several days ago but am leaving trying a new starter in another room for a few days just to let it all settle and blow in/out.


See what happens then. I read the website link and it's all pretty standard basic hygiene with a bit of overload on antiseptics in my view. Kill everything and you have nothing to start a starter...

But your advice is accurate in my view so thank you. I don't know about wet condition moulds/yeasts/fungi but I'm sure that is what has happened here now you have spelled it out.


Many thanks and I'll get back on this once time passes...


davo 2012 December 4

Without knowing if that actually is what is going on, I would think about getting the drainage looked at. It shouldn't get wet under any house. I assume by absoprtion trenches, you mean "aggie drains" (slotted pipes in gravel trenches, which run to a stormwater drain down the slope). But if water is bypassing these by either flowing over the top on the ground surface without absorbing into the gravel, or by leaking out of a downpipe or something, it ought to be able to be fixed so it stays dry under there - by a surface spoon drain or some other means to divert water away from the under-house areas, or fixing leaks. I had this in a house of ours once - and ended up having to replace floor bearers and joists (and the old Baltic floorboards themselves) which were largely rotted/borer-riddled because of the dampness (dry wood is much less susceptible to any of those things). In our case we had water from gutter spillage/leaking downpipes falling on a bare area and running straight under the house, where re-stumpers had cleared out some dirt and left some areas lower than the surrounds. After I did a bit of amateur pipe repair and drainage by concreting which cost about $50 and took an afternoon, it never got wet over a number of subsequent years, although we have since moved.

As to the disinfection - it didn't read too drastic to me - a bit of vinegar/alcohol mixed with water and sprayed around doesn't sound over the top - but I wouldn't bother with this until the drainage is sorted, and then I'd be careful about going under there without some kind of breathing mask.

Mould spores are everywhere, but it's the big accumulations of them that can cause health issues. Bacteria are everywhere, too, but that wouldn't mean you would ignore legionella if you had it in your house (not suggesting your mould is anything like that dangerous, but just mentioning for illustration).

Cate 2012 December 4

Thanks again Davo,

I spoke to my GP today about the sneezing and the mould (he's German and intimately familiar with SD and starters!). He said definitely under-house issue but precisely the same problem at his house and same solution only our trenches were put in prior to building and his had to go in later at a cost of $45k! The 'Ag drains' are 1m deep with a permeable cloth at the bottom, then 150mm diam ag pipe (polypipe with big holes) then road base, then approx 25mm gravel, then infill and they surround the house on the high side. As well as that, as we live on shelf of flat land at about 100m high on a very steep slope of some 400m, there is the same cut-off drain on the perimeter of the land at the base of the hill - so a two-front excercise in cutting off water.


Despite all of that work and expense, we still have bog-like ground over the heavy rains of a Tas winter - some 500+mm this year. The ground around the house - which is new - has been graded to take run off away from the house but the problem persists. There are springs underground that simply can't be cut off. The ventilation under the house is excellent so I think it's is merely a wet Tas place problem. Wouldn't happen in Hobart which is in a rainshadow area but where I am, in the far south, the rain is a problem when you also live somewhere with lots of good rich topsoil.


GP said simply keep the vent to the underground space closed permanently and that should solve the problem. Won't make the rain go away but might help my sneezing etc and allow me to make SD again! Foundations are all concrete block so no problem there. And heavily overspecified by the engineer because of the water and soil.


But gosh, thanks for thinking of me and my travails and for your advice and thoughts. And I agree the Vic Health site isn't too over the top - I did a quick scan and saw words like bleach/disinfectant etc. The thing will be cured I hope with summer heat and sun but hopefully not bushfire! One only 10km from here last Fri/Sat yet today is 9 degrees with snow down to 800m and 12mm rain in last 24hrs! Ahhh, Tas.


davo 2012 December 4

Yep I understand the Hobart rain shadow. I've been over a bit for work in years past and have a sister in Neika and another in Sth Hobart (and their respective families).

I will have to take our family back over to see them, one of these years!

Sounds like you have it sorted, as best possible, then.

Good luck!

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