Even the most fair-weather scotch drinker can't help but notice the near-constant stream of new bottles being rolled out these days – especially around the holidays, when the big-deal limited editions are released. That's the thing about aged spirits: As with vintage wines, once a particular batch is gone, it's gone for good, and distillers go back to the drawing board to tinker with something new to replace it.

Consider the outpouring of sherry-cask-finished scotch whiskies currently on the market: The idea is the whiskey is first aged in new oak casks (as required by law), before later being transferred to spent sherry casks to soak in more flavor. To be sure, it's not a new innovation: Scotland's whisky makers have been reusing spent sherry casks for as long as sherry has been imported there. Still, everyone from Glenmorangie to The Balvenie is taking it in different directions right now.

Legendary distiller Glenfiddich's take on sherry-cask finishing has been dubbed Malt Master's Edition (as a nod to Malt Master Brian Kinsman). Now, Glenfiddich utilizes sherry casks in a few other iterations (both its 30-year and 15-year whiskies are aged at least in part in sherry casks), but the Malt Master's Edition has another twist: This blend is first double-matured in two different oak casks, then left to mature in sherry casks. Glenfiddich hasn't released an age statement, so we have no idea how long it's in each barrel (and yes, we asked), but the distiller is bragging that compared to competitors that practice a similar approach, its Malt Master's Edition spends a significantly longer period of time basking in the sherry casks, resulting in a rounder flavor.

In the interest of science, we tested that assertion by sampling some Malt Master alongside a few similar-caliber offerings. It wasn't quite as sweet as Glenmorangie's 12-year Lasanta, which is "extra-aged" in sherry casks, but this isn't necessarily a bad thing. Compared with Glenfiddich 18-year (at $85, a similar price point), the Malt Master's Edition truly is much more round and full in the mouth – it's definitely more complex. Since there are just 18,000 bottles of Malt Master's Edition shipping to the U.S., though, we recommend making the effort to snag one, budget allowing, of course. [$80; glenfiddich.us]