Glenrothes Vintage Cask #7

I found this quite distinctive bottle on a shelf covered in dust at a local liquor store. I'm still uncertain how it ended up there, as this area is known for Fireball and Miller Lite, not single malt scotch. The combination of scarce information about this spirit and its affordable price led me to believe it might be an excellent find. The bottle indicates it was distilled in 1998 and bottled in 2015, meaning it had remained unopened for 5 years. It's a single cask bottling at cask strength, which is common for bourbon but unusual for scotch. Upon opening the bottle, I was met with a floral honey scent. The 58% ABV is quite apparent, with ethanol notes stinging the inside of my nose. It's not unpleasant or harsh, but it confirms the spirit's potency. The initial sips had an unpleasant sulfuric taste that worsened with each subsequent taste. Even adding water incrementally didn't eliminate the musty odor. The whisky concluded with a strong, lingering raisin note, reminiscent of inexpensive cognac. I was dissatisfied after my first tasting but decided to let it rest for a few days to allow it to interact with the newly introduced oxygen. My second tasting was vastly different! The delightful floral aroma is still present when opening the bottle, and I can now detect some bourbon-like notes as well. The sulfuric flavor has completely disappeared, replaced by a warm, full-bodied taste rich with honey and sherry. The raisin finish remains, but it's noticeably smoother and more refined. I confess I'm not very familiar with Speyside malts, as my experience is mainly with bourbon and Islay scotch. However, I recognize that this is an excellent quality spirit and unlike anything I've tried before. I intend to keep this bottle for a while and reserve it for 'special occasions.' I'm curious to see how it evolves with more oxidation!