We’ve all heard of or experienced the phenomenon of bottles changing their flavor complexion over time once opened. If you search the whiskey literature, industry experts will advise you that once a bottle is less than half full (some say a quarter full), you should drink it or possibly inject an innate gas like nitrogen to prevent the bourbon from oxidizing and ultimately affecting the flavor profile.
I’m a bourbon collector (but mostly drinker). I currently have ~80 bottles open in my home bar and tend to open more before I finish existing ones. Many distilleries have recently announced sherry-cask finished bourbons (Angel’s Envy, Town Branch, etc.). Thinking about those releases and hypothesizing the line up I’d like to have in a blind side-by-side tasting, I was looking through my open bottles of finished bourbons. I poured a solid 2 ounce pour of the Basil Hayden Dark Rye from a bottle that was less than half full and that I haven’t sampled in at least a couple months. From fresh bottles, I detect sweet notes of the port that is added (not finished) to the bourbon as well as a delectable nuttiness that makes me want to pair this bourbon with chocolate. To me, this is not a daily drinker but a ‘special’ occasion sipper for when I want something sweeter and less ‘bourbon-ish.’ However, tonight, I detect the same type of souring that one experiences with a bottle of red wine that has oxidized. The profile has noticeably changed and altered the taste for the worse. I’ve never experienced this phenomenon with a bourbon before and attribute it to the port that is directly blended with the Basil Hayden bourbon. As a scientist, I question the stability of a wine being added to a distilled spirit and recognize that oxidation has taken its effect on the port presumably before affecting the bourbon component of the blend. It’s not yet a ‘drain pour’ but it’s close. For now, I’ll finish this dram but won’t enjoy it nearly as much as I did the first pour from a fresh bottle.