These whiskies have been created by bottlers who have bought choice casks over the years. Sometimes they themselves have matured them, having bought the spirit directly from a distillery. Although many can no longer be found in retail, you can search them out on the secondary market – either through online forums and auctions, where the best prices will be found, or through specialist shops.

At the time of tasting, some of the whiskies listed here could be found online. I recommend snapping them up without delay. However, I suspect they will have already been sold and will need to be pursued on the secondary market. Two of the most respected auction sites are scotchwhiskyauctions.com and whisky.auction. As with all rare and expensive whiskies, you should beware of fakes; reputable auctioneers are adept at weeding out suspect bottles.

Speyside is the region with the greatest number of distilleries and is prominently featured in our collection, although there is something for all palates. We have ex-bourbon cask-matured whisky from Glenlivet and Benriach for those who like sweeter vanilla and fudge flavours. For those who favour big Sherry bombs, there is a Glen Grant 30-year-old expression. Moving away from Speyside, we taste two fabulous Bunnahabhain expressions, of which the 1997 is unpeated and the venerable 50-year-old 1968 is a rare peated ex-Sherry cask. This last was our pick of the bunch.

Ex-Sherry-cask whiskies are good to collect. They are very popular, though, and only 8–9% of casks are ex-Sherry, making them rarer than ex-bourbon. Aged ex-Sherry casks are rarer still, since they will be old casks rather than the seasoned casks produced in Jerez today purely for the Scotch industry.

All these examples of Scotch exhibit the characteristics of whiskies bottled at great age. We have included one Irish whiskey, which is gaining in popularity; single casks of Irish malt whiskey are becoming very collectible. Bushmills was, for some time, the only Irish distillery producing malt whisky, so single casks are hard to obtain.

Independent bottlings can offer great value for money and range of choice. Those featured here are some of the best examples, and those not normally bottled as single malts are great expressions of their respective distilleries.

Value for money doesn’t necessarily mean they are not as collectible as distillery bottlings. Most whiskies of 30 years or more coming from a single cask would represent a good investment, as long as their quality is known to be high. Those expressions rarely seen as distillery bottlings, such as the Auchroisk, are rare and highly collectible. Expressions from iconic distilleries such as Ardbeg will also come at a premium, because single-cask bottlings are also in short supply.