The Family Casks range of bottlings, for example, include vintage whisky for every year back to about 1954. The interesting thing about this range is that the casks on offer run through first, second, third and even fourth fill to what are described as plain casks (Fifth fill? Sixth fill?!)
Now, if you are planning on keeping whisky on the wood well into its fifth or sixth decade, fresh oak is most decidedly your enemy. Whilst it's true that whisky will take most of what it extracts from the cask in the early years of maturation, that extractive process will continue for the entire time that the malt is in the barrel. So for liquid which one intends to bottle after forty years, a fourth-fill cask will produce a much better result than a fresh, first-fill cask. After forty years a first fill cask would most likely be undrinkably tannic. On the other hand, and as is the case with tonight's fine dram, forty years is a useful span of time if you plan on using plain casks.
(I should note that as far as I know, Glenfarclas don't specify the casks used for this vatting as precisely as with the Family Casks range. So I'm speculating, mainly on the basis of how the whisky tastes.)
Appearance: a deep, deep nut brown, much darker than most drams. Is that natural? I hope so.
Nose: old mellow and woody. There's a very restrained sherry note, but what dominates is the kind of elegant oak perfume I associate with Armagnac, something which reminds of old varnished wood warming in the sun, or of lavender furniture polish.
Palate: Supremely smooth. Sweet and gently sherried, with dried vine fruits, treacle toffee, and the other kind of toffee that has raisins and brazil nuts in it. Again, I'm strongly reminded of old Armagnac - there's not a lot of malt character.
Conclusion: the parallel with Armagnac is very interesting. It's the practice there to age brandy for many many decades in wood, and fifty year old spirits are not uncommon.
This is a very fine dram indeed, and in comparison with more or less everything else on the market at that age, the price tag of £300 seems like something of a bargain.