19th century Scotch found in Antarctica

[Dale Seago]

Remember guys, the age of the whisky relates to its years in the cask BEFORE bottling, once it is in the bottle generally its flavor can only go downhill due to cork rot, evaporation through the cork, any possible damage done by prolonged exposure to extreme cold (not something normally tested on most whiskies), etc... so no matter how many years it has spent "on ice" in Antarctica it should not taste any better now than it did when bottled, and if anything maybe worse. If I remember Mackinlays was a relatively common blended whisky that just happened to be the preferred brand of Shackleton readily available at the time of the expedition.

Quite correct. It was originally (1875-ish) being sold as a vatted whisky, which nowadays would mean that at least it was all malt. Now, however, it's explicitly marketed as a blended whisky.