Another sour related questions

[suzanneb]

hi
brewed up my second batch of breakfast stout clone.
i bottled a couple after a very long primary and they tasted great.
Added coffee to the remainder and waited about a month.
now after kegging there is a sour taste in the beer while the ones bottled before tasted perfect.
i was really careful with sanitation and the coffee was brewed with boiled water then cooled quickly in freezer.

this has happened on a couple other batches recently.
Any idea where the sour may be coming from?

i am real careful with sanitation and the like.

 

[DSorenson]

A couple questions:
What kind of yeast did you use?
How much head space did you leave in your secondary (sounds like you used one) ?
At what temp was the coffee water when you added it?
Have you been reusing bottles?

 

[suzanneb]

A couple questions:
What kind of yeast did you use?
How much head space did you leave in your secondary (sounds like you used one) ?
At what temp was the coffee water when you added it?
Have you been reusing bottles?

Yes reusing bottles
Coffee was 75 when added to secondary
I dont remember how much head space there was
Yeast was american ale
Thanks

 

[DSorenson]

Well my first thought is perhaps the bottles have mold in them as a result of leaving beer dregs in them. Mold is hard to remove one it gets in there. I usually use unscented oxyclean. My second thought is that maybe there was a temperature difference large enough between the beer and the 75 degree coffee additive that it thermo shocked the suspended yeast, causing off flavors. It could also be that, in your scrupulous cleaning, one of the surfaces your beer contacts has been scratched. This would create a space hard to clean and sanitize; perfect for bacteria or wild yeasts. Does any of this seem plausible?

 

[suzanneb]

Hey

Not sure if bottles are plausible because i kegfed a batch and it is sour. Though the carboy could have something. I cleaned it pretty good with pb wash and then star san sanitized. I also just split a 3 gallon batch into 3 one gallons. The one i bottles is sligjtly sour.
Dont think that it was coffee temp was real close to room temp.

Yhe only thing i can think of is wild yeast in the air or the carboys. Is that possible!??

 

[DSorenson]

It is possible that you could have some wild yeast in the air that is resilient with the presence of alcohol. Or perhaps bacteria. Check the area around your brewing spot. I might venture a guess that there might be spoilage around somewhere. Or maybe there is a temperature issue? Any time there is fermentation the temps need to be monitored including bottle conditioning. Are you sanitizing your bottle caps? Do you cover your bottles after filling and before capping? Man... this is a tough one...

 

[DSorenson]

Oh... one more thought... what do you put in your airlocks? Or if you use a blow off...what do you submerge it in?

 

[suzanneb]

I use star san solution for the airlocks.

I am thinking i either have an infected carboy, though i am not sure how to clean it any further. Or i am getting some sorta contamination from having kombucha in the house. Is that possible?

 

[DSorenson]

Could be...any thing is possible. Try changing out the fermenter maybe. If that solves the problem, use that old one for brewing wild beers!