When I had almost finished my keg of “quaffable porter”, I decided to bottle the remainder with my new beergun. These were only four bottles, it appeared. When I tried one yesterday, a couple of weeks later, the porter from one bottle had an unpleasant, slightly sour flavor. Today I checked another one, same flavor. Completely unlike the kegged beer. So I wonder what has caused that. I’m pretty anal about the bottles themselves. Also, there was no additional carbonation, to the contrary, I had some CO2 loss due to bottling with the beergun. The beer did not really taste infected either, just different and a bit more sour than the kegged version. But can it be anything else than an infection? Also, I have a keg with pressurized star san that I use to clean the beergun, and I’m pretty sure the beergun line was completely empty when I started filling.
I guess you are going to say the beer picked up something, but what, and where?
I really can’t speculate where the infection came from. You can try to identify the type of problem with a bit of patience.
Warm up a couple bottles to about 21-24C for a week or two.
You should wrap them in a towel and have them in some kind of a container as a precaution against bottle bombs. This is basically to force them to ferment at high temps to make anything that is still alive active.
An infection will become much more pronounced. More sourness indicates a bacterial infection. More phenolic (clove/band-aid) will indicate a wild yeast infection.
(It is also possible to have both.)
Wild yeast cannot be killed by star-san. You should use a second sanitizer such as iodophor on all of your equipment during your process and probably should replace any plastic or rubber parts that came in contact with this batch during/after the bottling process. Bacterial infections can take hold if the star-san’s pH gets too high. Any pH above 3.0 is considered too high and will be ineffective.
Who knows how that line was stored and what was in it? I always sanitize my gas line connecting to my beergun. Gives me peace of mind. Do you have a beergun?
If the line wasn’t sanitized he could be blowing all sorts of stuff into his bottles when purging them with the gas from the hookup line.
I can confirm it was not an infection. Yes, there was a sour tang to the beer, but nothing that even hinted of infection. One taster mentioned blueberries, and indeed, the first thing that comes to mind when trying to describe the sourness is a blueberry-fruitiness.
Sourness mellowed as the beer stood in the glass but remained present. Totally screwed the beer over: where it was quaffably toasty when sampled directly from the keg, it was borderline drinkable and slightly yucky from the bottle.
Mulling this over, I am reminded of a famous Belgian brewer’s proclamation that a suspect batch of his should be decanted (and I’m paraphrasing but only slightly here) “to let the carbonic acid dissociate, allowing it to escape as CO2”. However, HE’s porter was not so excessively carbonated to even contemplate the relevance of that proclamation (about which I harbour strong reservations anyway).
Could crystal/caramel malts be responsible for this sour tang? For some reason, I’m suspecting they might, but have not found anything to back up that suspicion.
So I tasted another of the 4 bottles that I filled with the beergun, 3 weeks later, and it’s clearly an infection. 99% sure it’s the beergun, what else would it be?
So what is a foolproof way of cleaning the beergun? A couple of weeks ago I ran some caustic soda through it, let that sit for a while, and then ran Starsan through it. But Mr OCD in the back of my skull whispers in my ears (not sure how he does that) that this may not be sufficient…
You may want to e-mail Blichmann support and see if they think that it’s possible that a dirty gas line could contaminate your bottles. I’ve always skipped any sanitizing steps with gas lines, but that’s because I’ve always heard “nothing can live in an all CO2 environment”. In fact, I take the same approach with the inside of the tubing on my oxygenation tank (choosing to believe nothing could live in there), but it’s not like that thing stays pressurized with CO2 all the time.
Anyway, I think you’ve just made me paranoid, but it seems like at this point you’re not going to come up with any clear answer to how the beer became contaminated. It seems like this is one of those rare cases in brewing where you change lots of things at once and see if the problem goes away.
A buddy of mine had a beer win in one comp a couple weeks after bottling from keg and then got a terrible score a couple weeks after that - he went back to compare a couple extra bottles and found that they were infected. The culprit - a dirty QDC on the beer side used for the Beer Gun.
I don’t see what else it could have been beside the beer gun. The keg was ok for more than a month and I’ve never had an infection from a dirty bottle. Plus, all for bottles I filled were infected. And your paranoia makes me even more scared.
So you had about 4 bottles left in the keg that had been sitting still long enough for you to drink from the tap all but those 4?
Did you wiggle the keg at all prior to bottling?
The symptoms and tasting notes sound to me like you disturbed some sedimentary yeast and dark malt particles back into solution.
When I bottle with my beergun I enjoy from the tap until its hit that “perfection” stage, then I attach the beer gun without moving the keg AT ALL and bottle what I need.
Yes, I wanted to hand out a few bottles at the end of the keg. Only four could be filled. And yes, I moved the keg around to use the beergun. But the bottle I tried the other day was a slow gusher, and tasted very thin, so I’m not convinced by your explanation.
All the symptoms of infection are present - sour flavor that increases over time, thin body, over carb. It has to have been during bottling, so take everything apart and clean it. When I got my beer gun it had instructions on that and came with a brush to clean the insides. I always take apart the quick disconnects and clean them as well when bottling for competitions. It amazes me how much crud grows in them. I’ve never spent much effort on the gas hose, but I do soak it in sanitizer before use.
So this past weekend I actually used my beergun for the first time, bottled a very hoppy IPA. Did not even think once to clean or sanitize the C02 lines, and even used the same C02 line that I use to carbonate my kegs and attached that to the beer gun, thus thinking the C02 line in the accessory kit was unnecessary.
My processwas I cleaned the bottles with PBW, then used sanitized with starsan, then used the beergun to purge, then fill and cap. Drank the first one yesterday, 3 days after bottling, and it tasted a little funky. My first question, is any tiny amount of starsan left over going to affect the flavor? Is the consensus to sanitize and clean the c02 line going into the beer gun?
