Think I've got my first infection

[mosto]

Been brewing about three years and, up to this point, infection free. I don't claim to have the best sanitation procedures, but so far they seem to have been adequate. Brewed a Kolsch about a week ago, I no chill and ferment in the cube (20L jerry from Bunnings). I was using some harvested yeast, but only managed to harvest a very small amount so stepped it up over a few days, so the Kolsch just sat in the cube in the shed until the yeast was ready. Was in the shed last night enjoying a beer and watching some cricket when I noticed a whistling sound. At first, I thought it was coming from the ferm fridge, but no. After a while I worked out it was coming from the cube containing my Kolsch. I loosened the cap and a whoosh of gas raced out. I then peered in to see a large greenish krausen. Had a whiff, and while it's not the greatest smell, I've smelt worse from fermenting beer that was fine. I've never tasted infected beer and assume you'll know when you taste one.

I figure this all part of the never ending learning curve in brewing. I'll have a taste tonight to educate my palate as to what an infection tastes like. If it doesn't taste bad, I will probably let it go and see how it finishes up.

I'm assuming infection, as it's fermenting by itself, I didn't add yeast. However, when I cleaned this cube it was done more quickly than normal. Usually, I rinse it out a few times with water, then chuck a couple of litres of boiling water in with some Aldi Napisan, swish it around and leave it for a day or so before rinsing and swishing around a couple of litres of Starsan solution, which stays in there until I need it. This time, I kegged a batch from the cube I needed to use while I was mashing so I tipped and rinsed the napisan as soon as I'd finished swishing, then put the Starsan in until my boil had finished.

Is it possible, given this cube had healthy yeast in it only a couple of hours before, that some survived in a nook somewhere, and being healthy, kicked off once it had the chance? The yeast in there previously was US05. I realise this is grasping at straws, and it is most likely an infection and I expect it to taste like arse. But if it doesn't, any harm in letting it do it's thing? If I do that, would I be better off bottling instead of kegging (providing it gets to a low FG obviously)? My thinking is that if it does somehow turn out drinkable, but it is still an infection of some sort, I don't want to contaminate my kegs etc, or if it is an infection will it in no way be drinkable?

 

[beercus]

Did you fill the cube while the wort was still close to boiling temp?
All air removed?
sealed tight? With gas escaping maybe not?

This should be enough to sterilize if the wort is hot enough. And the starsan is extra insurance.,....

Beercus

 

[mfeighan]

must be the dreaded no chill botulism!

 

[mosto]

Wort was about 85C from memory. I squeezed and got pretty much all the air out. I thought I did the caps up tight but, as you say, the fact gas was getting out means air could have gotten in.

 

[Dan Pratt]

it sounds infection but only you will know when you taste it...... I dont think that any yeast from the previous batch using US05 woudl survive that temperture, would be nice though if it were that robust.

I used to add 2litres of boiling water and swish around aswell, these days the day before I brew I top it up with 5lts of 58c water and the rest with 18c tap water and let all the foam overflow until its full, cap it and leave that to sit for at least 24hrs, empty before transfer, rinse with water and then swish 1lt of starsan solution around and let that sit for 5mins before transfering wort, wort which is cold not for no chill.

Its odd that 85c wort didnt stop what ever it was still inside the container, maybe it was just on the lid?

 

[contrarian]

I've only had one swollen cube since I have been no chilling and in retrospect realised that the cube had been previously used and then left for a couple of weeks with the last remnants of wort. No doubt there were a few things growing in there that even the heat didn't stop completely.

I just chucked it in a fermenter with some healthy yeast and let it go, fermented out normally and the beer tasted fine.

Since then whenever I finish with a cube I rinse with cold water and then fill with warm water and napisan until its services are required again. Rinse a few times with cold water, starsan then fill. No issues with this process.

 

[mosto]

Well, definitely infection! Unscrewed the cap when I got home and the greenish krausen had turned to a thick green sludge that oozed out the opening, and smell was putrid.

 

[Pogierob]

Bugger...

 

[contrarian]

Doesn't sound too promising..

 

[NewtownClown]

Its odd that 85c wort didnt stop what ever it was still inside the container, maybe it was just on the lid?

Not at all odd.
Whilst boiling water at 100c will kill microbes in the vegetative or cell state, the spores can survive. Given the right environment (say, wort) and enough time, the surviving spores will germinate into bacterial cells.
Normally, the survival of spores wont be a problem, for their environment will soon be dominated by yeast cells, and any bacteria that is germinated will be out competed for resources.