Infection, wild yeast or something else?

[Squad1Guy]

I (kind of) recently finished fermenting and bottling Denny Conn's Vanilla Bourbon Porter. I have been anticipating this one for months, so imagine my dismay when I cracked one open at about 6 weeks in the bottle and it tasted sour! I am not sure what to attribute it to. It tasted fine after fermentation (at bottling), and the one I had at about 2 weeks also tasted fine. I decided to let it sit for another month to carb up and let the flavors meld. The last two I have tasted ha a distinct "sour" taste to them. I used S-05, and I know my initial fermentation temps got a little high (maybe 68-72) for a short period of time in the beginning. That might have caused some ester production, so THAT is a possibility. I may have also been a .....little..... heavy-handed on the bourbon when bottling (like twice the amount that is called for in the recipe - Maker's Mark FWIW), so THAT could be an issue. I guess there could be some random wild yeast at work too although my sanitation practices are pretty tight.

Any ideas what could be going on? This was going to be a nice winter warmer for this year, but I am contemplating just packing it away until NEXT year (if aging/mellowing will help this guy out).

 

[Squad1Guy]

A lot of looks but no replies? Nobody has an idea what's going on? Say it isn't't so!

 

[day_trippr]

It was infected. It would be sheer speculation to name the culprit, but there are plenty of bugs that will sour beer. I don't think you can get "sour" from US-05 even if run hot, and you sure as heck won't get any off-notes from Maker's Mark (excellent choice, btw - it's our house bourbon).

So you're pretty much left with an infection...

Cheers!

 

[Squad1Guy]

Thanks. That's what I figured, although I'd hoped otherwise :-/

 

[RM-MN]

Hold onto that beer a while longer. What you may be tasting is acetaldehyde which some people have reported tasting like green apples (sour?). If that is what it is it should go away in a bit more time. If it is an infection, it will get worse in a bit more time. Check again in a couple weeks and give us a report.

 

[Squad1Guy]

Hold onto that beer a while longer. What you may be tasting is acetaldehyde which some people have reported tasting like green apples (sour?). If that is what it is it should go away in a bit more time. If it is an infection, it will get worse in a bit more time. Check again in a couple weeks and give us a report.

Will do. I am hoping for the best here.

 

[Squad1Guy]

Hold onto that beer a while longer. What you may be tasting is acetaldehyde which some people have reported tasting like green apples (sour?). If that is what it is it should go away in a bit more time. If it is an infection, it will get worse in a bit more time. Check again in a couple weeks and give us a report.

OK....an update.
I tried another bottle after about two weeks (but from the other side of the carton). I thought it tasted pretty good! I didn't notice a sour taste but SWMBO said it was still slightly sour. That seems to point toward acetaldehyde as the culprit, although I did use poor scientific method by changing two variables at once :-/