Bad tasting beer after keg to bottle transfer

[DanseMacabre]

I've been extract brewing for a couple months now. Almost all of my beer goes into kegs, and so far I've been very happy with my results. I've found that when I transfer delicious beer from keg to bottle (via beer gun) that some of that beer goes bad after a little while. The first thing I notice is a slightly sour taste (I warn you in advanced that my ability to describe these off tastes is lacking). It's as if I can taste the true essence of my beer (as it tasted in the keg), but there is this slightly sour/fruity taste in front of it. This taste occurs anywhere from 2 weeks to a month after transferring carbonated beer from the keg to bottle. I've also noticed this same off flavor in a friends homebrew that was bottle carbonated and sat in storage for a long while (a hefe). The second stage of off flavor occurs after about a month in the bottle. During this second stage the beer just goes watery/stale/astringent/skunky; leaves a dry coating on your tongue. Since I've become more adept at tasting off flavors in beer, I've noticed this stale/astringent taste in other bottled beers. So maybe this is simply oxidation?

The brews that have suffered this fate to date are IPAs and brown ales. I'm currently drinking a milk stout that I bottled from keg 3 weeks ago...no such issues (maybe a little watery and maybe more time will tell).

At this point I assume my beer gun technique or sanitation is the issue. Sanitation has never been a problem with any other part of my brewing process, so I find it hard to believe this is the case.

Anyone have any experience with beer turning on you from keg to bottle? I like the idea of saving small batches of all my kegged beer for future sampling, but if it is going to continue to go bad, I'd rather drink it up now

 

[Hex23]

I did recently have an experience of a German lager developing a very slight vinegar-like flavor when I went from secondary/lagering to the keg. I assume it was an acetobacter infection. The beer tasted very nice and malty going into the keg and the very slight vinegar-like flavor ended up masking much of that malty goodness. The beer was still very drinkable. In my case, it was a used keg, but I thought I cleaned and sanitized it well. I did not however pump sanitizer through the dip tube and I think maybe that was the source of the problem. Next time (for my current beer) I took out the dip tube and cleaned with with a dip-tube brush, let PBW sit in the keg overnight, scrubbed overall with a brush, rinsed, then pumped through some star-san solution. That beer just went into secondary (I'm lagering in the keg), so we'll see if the problem happens again.

In your case, I wonder if you should take the hoses off your beer gun and do a thorough cleaning.

 

[DanseMacabre]

Hex,

A more thorough cleaning of the beer gun and bottles is definitely the best place to start. If I still have problems after being more vigilante about sanitation, maybe I'll start bottling a small portion of the beer with sugar and keg the rest so transfer isnt necessary. The beer gun is great if I wanto to fill some bottles/ growlers and drink quickly (i.e. transporting beer from my place to a friends house over a weekend), but right now it is letting me down for long term storage of kegged beers.

DM

 

[Hex23]

That sounds like a good experiment. I bought a Blichmann beer gun a couple of months ago and haven't bought the accessories I need to get it up and running. I'm really looking forward to using it though. On all my previous kegged brews I just used the cobra faucet to fill a growler - works fine for a growler but would not be good for filling bottles.

 

[Fid]

Is the bottled product loosing carbonation overtime as well or just changing flavor? I'm going to agree with the others and say that your cleaning and sanitation practices are probably a good thing to look at as well. When you're running beer from a keg, through the post, through a connector, through a beer line, through a gun, and then into a bottle theres plenty of places where something nasty might be hiding.
If your bottled beers aren't staying carbed maybe you're knocking alot more co2 out of solution while you're filling them than you realize? I feel like that would make sense if you're experiencing oxidation issues as early as two weeks after transfer. I'm going to be honest, I've never used a beer gun or attempted long term bottle storage after transferring out of a keg but I've heard that it helps to use cold bottles that you've sanitized, covered, and stored in the freezer the night before bottling to help keep the co2 in solution.

 

[DanseMacabre]

Fid,

Thanks for the cold bottle advice. It makes sense, and I'll give it a try with the other suggestions