[musseldoc]

I made a German lager that ended up with a little DMS in the finished beer.  Otherwise, it was malty and delicious with no oxidation or contamination character.  I wasn't sure if the DMS might correct itself with some lagering, so I decided to try to scrub it out with forced carbonation.  For a week, each day I released the pressure in the keg, then repressurised by filling through the liquid stem.  This bubbled CO2 through the beer, and I hoped would force out the DMS.  I don't taste much DMS now, however, the beer tastes like it has aged past its prime and tastes oxidized.  I never took the lid off the keg or exposed the beer to air, so I am not sure why it is now oxidized. 

Anyone else experienced this while trying to scrub with CO2?  Thoughts?

FYI, 100% pils, FWH hallertau, 90 min boil, whirlpool chill, wlp833 (4L starter), 4 weeks @ 50F, transfer under CO2, 6 weeks @ 35F, 15 PSI @ 35F. 

[conley]

was your beer at warm temperatures while you were scrubbing the beer?

it is possible that your off flavor is not exactly connected to what you are thinking it is. Off flavors are a tricky business, just double check your brewing process to be sure.

[narvin]

It's possible you also lost hop flavor and aroma, leading to a washed out beer (but not oxidized).

I had a Saison that was overcarbonated in the keg, and I definitely felt like it lost something when I depressurized the excess.  I thought that t almost tasted oxidized at first, but there's no way it was exposed to air.

[conley]

I didnt even think about pulling out the other flavor and aroma compounds from washing, good catch narvin.

[ynotbrusum]

I mistakenly carbonated a keg one time putting the CO2 on the wrong post and it tasted "washed out".  That's a great way to describe it.  Now I use red o-rings on my "in" posts - problem solved.  Even better is to paint the rubber on the "in post" side of the keg as mentioned in Zymugy.