wort started to ferment without yeast

so this is a sad story. i made a wonderful brew, porter-like beer, made the wort, cooled it, aerated it and put in the fermenter. Now, I left it in there for 3 days without pitching yeast. the reason was i ran out of yeast without taking notice. so i got my yeast today and wanted to pitch it in, BUT i heard the airlock bubbling!! so i opened up the fermenter and a really foul smell came out and bubbles on the top.. what the heck just happened??? i sanitised everything! snif snif snif ...

Sounds like a Lacto infection.....

Bubbles in the airlock don't really mean it's fermenting. But if it smells really bad, chances are something bad got to it

but everything was superclean..

3 days is a long time for wort to be sitting, no matter how sanitary you were....

argh.. lesson learned..
thnx guys!

akardam said:

but everything was superclean..

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Yeah, but you tempted fate by leaving it for three days. Sanitation may buy you some time, but you should never count on it, if you can help it.

how did you aerate it?

unless you sterilized everything (which is practically imposable) there are still a few bacteria and what not on every surface. thats why cleaning products only claim to kill 99.9% of germs. 3 days is plenty of time for the survivors to party and start eating your brew.

by the way, any chance of saving it??

you can try boiling it again to kill anything that is currently living it it. but the damage is already done. there is no telling what kind of byproducts the wild what ever put into the beer. you may end up with undrinkable crap.

i have this wort aerator, like a fish tank bubbler, with a sterile filter..

i'm pissed off now, 5 beautiful and hard brew hours down the hole..

damn.. what was i thinking! can't believe i brewed without having yeast.

so in summary, a) pitch in yeast as fast as possible, b) probably lacto infection when having foul smells, c) sanitising doesnt do magic and d) can't really be saved if infected.

akardam said:

damn.. what was i thinking! can't believe i brewed without having yeast.

so in summary, a) pitch in yeast as fast as possible, b) probably lacto infection when having foul smells, c) sanitising doesnt do magic and d) can't really be saved if infected.

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Seriously, you could boil it to kill whatever is in there...

Maybe even try a sample after boiling, see how much damage was done...

akardam said:

damn.. what was i thinking! can't believe i brewed without having yeast.

so in summary, a) pitch in yeast as fast as possible, b) probably lacto infection when having foul smells, c) sanitising doesnt do magic and d) can't really be saved if infected.

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a. yes, but only if the wort is at pitching temp.
b. maybe, maybe not...doesn't really matter does it?
c. santizing is what it is...with it, you are simply "knocking off the big chunks" its not sterilization.
d. I dunno....if its worth your time, boil again and pitch....you never know. At this point that 5 hours is a "sunk cost" of brewing. Is it hauling out the equipment and another hour to boil again? Maybe, that is your call.

There are entire beer styles out there based on lacto and Brett infections. Probably take a year or longer to be drinkable. Its all what you are interested in.


edit to add: If you do decide to boil, you will kill the infection but you likely won't get rid of any byproducts they have produced (and is giving the stinky flavors/smells). FYI....

buy a handful of cheapy dry yeast....just like its been said 100 times on these boards. It's saved me mor than once. Most of them will work fine even years after their expiration date. I have like four packets of coopers for emergencies only.

maybe giving it another boil isn't that bad of an idea. i can easily so it, even though i probably need oxygen mask because it really stinks.. in any case, i'll stash up on dry yeast for future reference.. i didn't ever realize wort is so fragile and bound to infection so easily

I would contemplate leaving as is for months. You could wind up with the best tasting sour/lambic you've ever tasted.

I'd let it run it's course. It might be wild yeast and not all of them are bad.

Taste it.

akardam said:

i didn't ever realize wort is so fragile and bound to infection so easily

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Its not really....what happened is that you left the wort without something growing in it in the ONE critical point of the brewing process. The "danger zone" is when the wort is between the temps of 40 and 140F. At that point you basically have is microbiological growth media sitting there and the first microbes to get in there and grow are going to be the ones that set up shop in there. Once you get yeast growing in there, its awfully hard to get an infection.

I'm in the "let it go" camp. I think boiling it again might just ruin it more. Just let it go and consider it an experiment. Chances are there is more than just bacterial growth there. You could have some wild yeast and it might just be a good sour beer. I would let it sit for at least a couple of months though, to mellow some of those sharp flavors. Give it a taste every few weeks... good luck!

olllllo said:

I'd let it run it's course. It might be wild yeast and not all of them are bad.

Taste it.

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Yeah if you can spare the fermentor let it run. Who knows, in a few months you might have a fantastic sour porter.

oh I forgot about the aeration bit.. I got that aerator from a shop in London and brought it back to Stockholm so I was looking around for a proper outlet plug which I did not have at the time of the brew (3 days ago). so i didn't aerate it at all! just remembered, i intended to do it right before i pitch the yeast..but now..

if i leave it, you guys reckon the stench will go away? it really reeks! damn peirate mircrobes haha

You could leave it and see what you get. You could also pitch some yeast and come out with a more "conventional" sour beer.

Depending on your air lock you can throw a 40mm nato gas mask canister on top if it's a three piece airlock. If you don't have those available some sort of activated charcoal filter taped to the top or over a bottle that you have the blow off running to should take care of odor. This is how I keep the wife happy when using white labs cider yeast for making cider, that stuff puts off a bunch of sulfur.

I'm in the in-between school of thought. don't boil it, but pitch some yeast and let it finish out. Give it some extra time though.

Go check out the Wild Lambic forum on this site they may have some insights. Can you be more specific on the awful smell? Was it sauer kraut, dirty feet, or rotten steak. I did a second mash on 24 hour old grain that smelled like rotten steak and it turned out great after I beat the heck out of it.

https://www.homebrewtalk.com/f127/what-i-thinking-165148/

ChshreCat said:

I'm in the in-between school of thought. don't boil it, but pitch some yeast and let it finish out. Give it some extra time though.

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Agreed. ...and do a secondary fermentation?

You really won't know till after its in the bottle for a few weeks.

arkadam, any luck?

Best quote I have ever heard regarding home brewing:

"All homebrew has SOME level of infection... no matter what you do. There is bacteria EVERYWHERE, and one second is all it takes for bacteria to settle on your wort from the air. The best you will be able to accomplish is controlling the infection to a minimal amount."

So, 3 days is just asking for trouble. Although, I have done that myself and been ok.

Sorry about your beer. It will be mourned.

Sounds like you did a full-batch-sized George Fix Sanitation Test except for the '...need to check the sample often so you can accurately note the length of time it took your "sanitary" wort sample to start fermentation'.

thanks Dynachrome for asking! In fact, i am really puzzled. I was about to post results a couple weeks ago but I couldnt make sense of the phenomenon so decided to forget. So, what happened is that about a week into fermentation by our uninvited friends, the airlock stopped to bubble. I then decided to take a measurement to see the specific gravity and it fell from 70 to 30! And decided then to taste it, and it tasted okay except for a slight metallic taste and hint of sour to it. So then I decided to proof and add some Nottingham yeast to see if it could get down to 1.015, but nothing occured. It didn't do anything. However the most absurd thing was that initially my wort smelled completely foul!! Like something crawled in there and died! But, after this week of 'fermentation' it smelled natural and normal, this drove me nuts. So, i decided to label this beer as 'case closed' and forget about it..