Surprisingly, since Hazelburn has only been distilled at Springbank since 1997, the proof of the Hazelburn living cask was quite low at 48.2% when I visited on August 31, 2013. Looking at the bottles reported at WhiskyBase, it appears this has held up, suggesting that most of the casks added to the mix have had abnormally low ABV for their (presumably low) age. So while these may not be the most representative casks, they should be something interesting.
Cadenhead's Hazelburn Living Cask
Nose: warm caramel, rich brine, solid oak, oily (motor/olive), dry malt, floral, hints of moss, green tea, and sherry. After adding a few drops of water the caramel and brine are amplified, the fruit becomes muskier, and the oil becomes more firmly olive.
Taste: moderate malt and wood sweetness up front, becomes bittersweet with oak and tea tannins around the middle, joined by a light bump of vague fruit and floral esters, finishes with mild brine near the back. After dilution it becomes much softer and more integrated, with the tannic and bitter components dissolving into the sweeter wood.
Finish: dry malt, rich oak, bitter tannins, background brine, floral
This one took some time and air to open up. When I first popped the cork it was tight and resembled the red stripe Hazelburn 8 Year Cask Strength, which was pretty unappealing. With time it became much more rich and had more in common with the Hazelburn 8 Year Bourbon Single Cask I liked so much.
Like the 1842 Campbeltown blended malt, this isn't a world-beater, but I really enjoyed it. This cements my feeling that I vastly prefer bourbon cask matured Hazelburn to anything from sherry casks, which seem to override the salted caramel character that I enjoy. I really need to try the new Hazelburn 10 Year, which should be in the same ballpark.