What is causing a bad flavor after cold conditioning?

Question

I've had something happen to a couple batches and can't figure out what's going on. What happens is a major flavor change after the first two weeks of primary, but for the worse. Normally my beers keep getting better by the day wether I bottle or keg and seem to mature, but a couple batches have basically taken a bad turn and come out really similar even though they were completely different beers (Imperial IPA(bottled) and Helles Bock(keg)).

The helles bock was clear and bright after a two week primary and two weeks of lagering and then I moved it to a serving keg (with a jumper hose to not get any oxygen in) to get it off the settled yeast, and lager a bit longer. I sampled a couple glasses right after the move it was excellent, clear, tasted clean and crisp. Now after two weeks sitting in the fridge it is horrible! Also it seems to have gotten cloudy too.

One of my only guesses would be oxygenation, but the only comments I find claim oxygenated beer tastes like "wet cardboard"... don't really know what that would be, but doesn't seem like that to me.

Any ideas?

Answer 1

How would you describe the off flavor?

Most likely scenario is that the beer picked up an infection somewhere between primary and the keg. Maybe you've got something funky growing in your lagering fridge? In the jumper hose? The keg itself?

I'd suggest replacing all the beer line, and sanitizing anything you get bleach on.

Answer 2

I think Tobias is correct. It sounds like you've picked up some wild yeast or bacteria from somewhere. You need to clean everything that beer touches after boiling. I recommend:

• Replace all of your tubing.
• Disassemble and soak everything (that is plastic or stainless, including all of the new tubing) overnight in hot water and PBW or Oxiclean. Remember that you can take all of the valves for kegs apart, too.
• When the cleaner is rinsed off, soak everything again in a no-rinse sanitizer before putting it away.
• Next time you brew, sanitize it all again right before using it.

Answer 3

I realize this is answered, but if the beer is tasted better later, I doubt it's an infection. This might be totally off-base, but when you move to a keg and refrigerate, unless you filtered before transferring, the remaining yeast and sediment particles are going to settle to the bottom of the keg. The dip tube on a corny keg is pulling from the bottom, so when you go to taste the first few pints they will be cloudy and taste really bad because you're drinking all the yeast and sediment. I have been tossing the first few pints of a newly kegged batch, though I suppose you could let them settle and decant.