Perplexed About Diaceytl In A Single Bottle

[Murcluf]

I have a perplexing question that has been doing my head in for the last few days.
I brew an IPA which I kegged and had no issue with it, from that keg I CPF'd half a dozen bottles for comp and testers. The other day I opened the last 2 days first one fine just like the rest, the last bottle smacked of diacetyl big time. It didn't taste infected in anyway just smacked of butterscotch and had a buttery mouthfeel. The keg and bottles were maintained in the same controlled temps so I can't point to temp variation as a cause. Bottles kept and cleaned and sanitised exactly the same way, I just can't work it out 20 lts of a beer 500ml has diacetyl or diacetyl like taste to it.

 

[felten]

If you scroll down to the bottom here it talks about how diacetyl can come about from oxidation reactions

 

[brendo]

Oxidization would be my bet - it can revert ethanol back to diacetyl (it is a precursor) under certain circumstances.

This would be my bet in this case.

Cheers

Brendo

 

[Murcluf]

Thanks fellas, I take what is said on board with the diacetyl coming from oxidation which I'm surprised to learn. Knowing the processes I used to bottle the beer was exaclty the same for each bottle I would expect that none or all should of been effected if you follow the oxidised therory not just one. Anyway I think I just accept it as it happened call it diaceytl from oxidation and move on.

 

[Pennywise]

Can also be from an infected bottle, eventually it can take on lacto traits from what I've read. I've been having a few diacetyl issues myself...

Edit: Spellz

 

[MattC]

Perhaps a pediococcus infection. If its only one bottle its a def Possibility. Pediococcus bacteria are a known potential source of diacetyl.

Cheers

 

[Murcluf]

Perhaps a pediococcus infection. If its only one bottle its a def Possibility. Pediococcus bacteria are a known potential source of diacetyl.

Cheers

I suspected a Pediococccus infection in another batch of beer I had but that was in every bottle of that batch. I can trace that issue back to the smack pack I used. The IPA was a whole different lot including yeast. If i have an issue with Pediococcus in my equipment I might have to purges it as I have recently done a big clean up of my equipment. I'll do another and will have to see what happens as the minister of finance wont be happy if I have to purchase replacement equipment.

 

[raven19]

I'll do another and will have to see what happens as the minister of finance wont be happy if I have to purchase replacement equipment.

Perfect opportunity to duplicate the cold side of things mate, and turn current equipment into 'funky use only'. That will make Kenny and I very happy.

 

[Murcluf]

Perfect opportunity to duplicate the cold side of things mate, and turn current equipment into 'funky use only'. That will make Kenny and I very happy.

Thanks for the encouragement Raven but I think 12.5 is too hard a target to strive for, and will leave that to you to try and achieve. It's would be a mighty feat to reach the dizzy heights of Grand Masterdom. :lol: