Stout infected after priming?

[Good Vibrations]

Hi All,

Long time reader, first time poster. I've been brewing for about a year and a half now and I recently tried a Vanilla Bourbon Stout. Everything went well, I soaked the oak cubes in bourbon, dumped the bourbon and added to the fermenter after fermentation was done. Same with the vanilla, I added the concentrate from a couple beans soaked in a small amount of bourbon to the fermenter. Everything went fine, and I bottled (rather than kegged so I could age) - it came out at about 8.7%. After it carbonated I tried a couple bottles within the first month and was very happy with it. Seemed to get better and better with each on I tried. After about two months I opened one and it had a very chemically-taste. The closest thing it reminded me of was the smell of the pink urinal cakes in public bathrooms. Gross I know, but I have the nose of a blood hound and once I said that everyone else agreed.

My question is - what could have happened to my beer? What sugar would've been left to even cause infection? I assumed after it was carbonated everything would be fine! All I can think is that there was a TINY amount of fermentables left that hadn't fermented yet that happened in the bottle (though I didn't have any bottle bombs or over carbonated beer at all!). I'm stumped at why everyhting tasted great and turned a couple months later.

I left it in primary in my fermenting chamber for 6 weeks ( I know it's not recommended that long, but I gave it a shot and didn't notice any off flavors initially from the yeast). Any thoughts are appreciated!

 

[AGbrewer]

Could have been something on the bottle caps or the bottles themselves. Might have just been that bottle or just a few bottles.

Sometimes people forget to sanitize the bottle caps as well as the bottles.

I soak my bottles in PBW and hot water for at least 1 hour. Then rinse thoroughly and soak in starsan for at least 1 minute before putting them on a bottle rack for drying. Typically use the bottle the same day for bottling the beer. I also inspect each bottle to ensure there is no caked on residue. If there is, the bottle goes to the spirit in the sky.

As for the bottle caps, I soak them in Starsan before I start transferring the beer into the bottling bucket. I also make sure to soad my hands in the starsan for 30 seconds before beginning to handle the bottle caps. I'm also very cautious to not touch the rim of the bottles.

Lastly, I am cautious about what the bottling wand touches to ensure that it doesn't pickup something and put it in the beer.

Yeah, it's probably all overboard and overcautious, but after I had bottle bombs, I decided to be safe rather than sorry. Never had an issue since.

Good Luck with that. I'll bet someone smarter than me will have a better explanation or theory that might help.

 

[J A]

Only off flavor anywhere close to what you describe is geraniol but I can't imagine where it would come from in that beer. It's usually associated with more hoppy beers and when oxidized can be pretty obnoxious.

 

[Nosybear]

I was thinking along the same lines as JA and have a theory as to how it happened. Chemical scent - likely chlorophenols, the most common and preventable killer of good beer, or a phenol thrown by some bacteria. Flowery scent - esters plus vanilla. Overall: Contamination likely. Not sure of the source. By the way, some coliform bacteria can throw a fecal scent that some interpret as "flowery" (although not in a nice way).