Ask Mr. Wizard

Fading Hop Character

TroubleShooting

Jeffrey Gick — Leesburg, Virginia asks,
Q

I’ve been having the same issue for the last six batches of imperial IPAs. I make a clone of Russian River Brewing’s Pliny the Elder that goes from spot on in the secondary to rose-flavored maltiness that loses all its citrus/piney character two days after kegging. I’m very careful with sanitation and no common strains of wild yeast or bacteria were present when i had the beer analyzed. When I’ve asked Russian River brewer Vinnie Cilurzo and others, they suggest it must be oxidation since the beer changes so rapidly. I’ve tried to adjust my kegging process and used a longer siphon tube to make sure it reaches to the bottom of the keg and purged the keg with CO2 prior to the siphon. I cold crash in a refrigerator and the airlock reverses flow while the beer chills down, but I fill the airlock with Bacardi 151 to kill anything in the reverse airflow. Can the small amount of air that would enter during the reverse flow in cold crashing cause a significant oxidation issue? Or could my problem have something to do with my hops or bad CO2?

A
I think the most difficult thing about trying to troubleshoot brewing problems in my column is not being able to taste the beers that I am being asked about. I sometimes flash
Response by Ashton Lewis.