my bubbly tasteless infection - proposed solutions (with video!)
 

my breakfast stout has acquired some sort of infection - either bacterial or a wild yeast. after a month of stability and normal appearance in secondary, it spontaneously started fermenting again. tiny little bubbles started rising through the beer and would create large bubbles on the surface as they got caught in the oils of the brew (due to coffee, chocolate, etc). airlock peaked at 5 bubbles per second, and gravity dropped 12 points.

the beer doesn't taste horrible now, but this may be because it's hard to taste much given intensity of stout's flavors. it is slightly astringent but could be because of the ingredients: black patent, roasted barley, coffee, etc. the beer's body is getting thinner as one would expect with an infection that took me from 1.027 to 1.015. the predicted FG for this beer was 1.023, so we are well below what sacc can achieve. and it appears that we are heading lower:

i recently needed the fermenting vessel so i racked to a smaller tertiary carboy and bottled 15 bottles. i'm keeping an eye on the carboy, if gravity drops more than a few points i will be refrigerating & drinking those 15 bottles ASAP.

it appears that racking - i.e. exposing the beer to oxygen - kicks up fermentation. things had stabilized in secondary, or at least slowed way down, but after racking to tertiary the little bubbles appeared again. see video here: http://bit.ly/QB9QBQ (crank up the resolution to 480). the last 5-6 seconds contain the best view of the bubble rising up the neck of the carboy. remember, this brew is over 3 months old!

i fear that this infection will take the beer down to some ridiculously low gravity and leave behind nothing interesting. thus, in short order, i am considering one (or several) of the following solutions to kill whatever is in there and salvage whatever is left:

1) campden tablets: nuke with 1 tab per gallon, then let the beer sit for several weeks before re-yeasting and bottling.
2) heat: bottle, let carbonate, then pasteurize with heat by submerging the bottles in hot water. there are several threads on this board (like http://www.homebrewtalk.com/f32/easy-stove-top-pasteurizing-pics-193295/)
3) freeze: we've all had the experience of forgetting a beer in the freezer (beercicle). i'm thinking that a good freeze after bottling might kill whatever is in there. it should kill any wild yeast, at a minimum. not sure about the bacteria.

i could also let it run its course and wait for some ridiculously low FG (1.000 or less), but i'm concerned that the resulting beer will be too thin. currently it's still decent so i'm hoping to save what's left. maybe i can add some malto if i go the campden route.

all thoughts/comment appreciated. thanks!

I reckon you should wait it out,tasting at regular intervals and when it's steady over a few months, brew a fresh batch of stout with LOTS of body and blend it.

hi badlee,

thanks for your suggestion. the issue to keep in mind here is that the infection will still be in there even after FG and adding fresh beer = adding fresh food for the infection, so it'll get back to work and munch down on the new snack... and we'll be right back where i started, only with more infected beer.

however, your plan could work if i successfully killed the infection first, which only campden tablets might do. so i might just do that: give campden a shot, let that dissipate over a few weeks and then blend with a heavy body stout (maybe use a wine yeast that will leave a lot of complex sugars behind).

or maybe this isn't worth the effort anymore...

I'm not sure if you can remove a infection once it's in there.... I know campden will kill yeast but I don't believe it will kill bacteria though i could be wrong. I know though that the general consensus is once you have a infection drink it quickly before more off flavors become evident. the problem with all due respect to Badlee is that if you blend a infected batch with a non-infected batch is all you are doing is infecting the good beer. hmmmm.... I'm thinking hard about this and minus antibiotics ( which I don;t reccomend doing this ) I think you may be stuck. and your sure this is not your regular fermentation just re starting ? maybe it was stuck then just kicked back off again ?

Keg it, no problems. (except extra sanitizing after)

GUSHER.

My only bad infection.

Bottling is impossible.

it is not harmful or even bad tasting, but it keeps making gas.

i had to look it up here, but according to the wiki and yooper, campden kills bacteria. so campden should work.

good question, it's something i've certainly considered and i'm pretty sure it's not for a few reasons: one, how the brew looks. if you take a look at the video, you'll see the distinct little bubbles rising up through the brew. i've never seen a normal sacc fermentation look like that. second, apparent attenuation is now at 82% and it's still going despite 8.75% ABV. US-05 isn't known for hitting 80%+ without some pretty major tweaking... and i haven't done anything to tweak this batch (multiple late sugar additions, oxygenation, heat ramping, etc). i guess there is some miniscule chance that i got a super-mutant version of US-05... but occam's razor tells us that an infection is the right way to point my suspicions. and finally, i had previously hit an FG that wasn't too far off of predicted (1.027 vs. 1.023), and given my recipe i expected to be on the high end.

unfortunately i don't have a kegging setup. so if i can't kill the damn stuff, i might bottle it, let it naturally carbonate, taste them regularly to determine when they are sufficiently carb'ed, then put them all in a fridge. hopefully the cold will stall the infection and prevent it from becoming more carb'ed. might be the excuse i need to get a beer fridge - a silver lining!

thanks for your insights. anyone else?

Chances are this is not going to taste any better than it does now. If you can keg, keg it. If you are going to bottle, heat pasteurize it.

Cooling does help, but I am pretty sure that even cooled, a few weeks later you have gushers.

That is the beauty of kegging it......it doesn't need Co2 ;)

I agree... If it doesn't taste bad drink it as fast as you can. Maybe time to have a party? lol

i guess i should clarify that by "doesn't taste bad", i mean it doesn't have any off-flavors due to the infection (at least none that i can identify). however, the underlying beer - a big oatmeal/chocolate/coffee stout - would certainly benefit from more aging. i guess i'll be drinking this one younger than i would have otherwise liked to. and time to re-brew!

(EDIT on 12/21/12: this post was made in the early days of dealing with this situation. initially there was little impact based on tasting gravity samples. eventually the stout did develop an off-flavor and it was actually kind of interesting - worked well with the roastiness. this infection has since hit other beers that weren't as robust and they suffered from it. please continue reading this thread for more info...)