Wait, what just happened? (Infection post fermentation/after coffee bean addition?)

[Cpt_Mantastic]

Hey everybody!

First post, but I have been reading and lurking for quite some time. So, I just brewed a variation of EdWort's Robust Porter, and I say variation because I wanted to add coffee...And whiskey You know, a full on Irish Coffee Porter.

Anyways, after a week in fermentation my gravity numbers had completely stabilized and things tasted great. At this stage I decided, after much research and debate between cold brewed coffee and beans directly to the fermenter, to add coffee beans directly to the fermentation (in a nylon hop bag). I added ~5oz of freshly roasted beans into a starsan washed bag, closed things up (I did not rack to a secondary), and let it sit until time for kegging. Now, unfortunately I can`t comment on the flavor as I was racking to the keg (I swear it was OK, but maybe I didn`t actually taste it...Who knows, it was late!), but the keg had been thoroughly scrubbed (and soaked) with PBW and starsan just before racking. I had also added a few oz of single barrel Jack to the mix to complete the Irish Coffee theme.

Well, today I just checked on the carb level and found that there is a terrible sour/tart backbone flavor (with no real aroma hinting at it) that was not present after primary was complete. It is completely undrinkable at this stage and unfortunately means that I get to dump the 5g in the keg. I am just not certain what caused the issue as this is the first significant problem I have run into (all 4 all grain batches under my belt ). From what i have read, it seems like a lactobacillus infection, but I am not entirely sure. Has anybody else had coffee beans cause this?


Thanks and definitely looking for any advice/ideas!


Short version:
-Base recipe EdWort's Robust Porter
-Hit Gravity Numbers perfectly
-After steady FG readings, added 5oz coffee beans into the fermenter
-Flavor was great at this stage
-After kegging flavor is very sour and undrinkable, although the aroma wouldn`t lead you to believe it would be that way

 

[ColoHox]

It is difficult to pinpoint the source of contamination in most cases. In this case, I would say it was the beans.

Coffee beans often have Lactobacillus on their surface, so it is crucial to sanitize both the bag and the beans themselves. Next time, try cold brewing the coffee and adding that to your beer.