Nick Brown wrote:However, if a virtue is made of the type of whisky previously held in a refill cask, then it becomes obvious that it's not just the wood doing the flavouring - it's the previous contents of the cask.
Have you just figured this out? Of course
the previous contents have an effect. This has been true for as long as Scotch distillers have been using second-hand barrels. If the Balvenie Islay Cask is a vatting, then every malt on the market is a vatting. Of course, some are vattings of whisky and sherry, which isn't even whisky at all--what would you call that, Nick? Hey, the even name the type of sherry sometimes. Horrors, they're flavoring the whisky with Pedro Ximenez! Sorry, you're about 150 years too late to stop that trend.
This is a lot of hoohah over exactly zippo. Casks are reused all the time, and I'd bet a fair number get swapped from distillery to distillery in the course of trading. In this case, Balvenie saw an opportunity to a) do something different with their whisky at a time when many distilleries were experimenting, or b) jump on a marketing bandwagon. Take your pick, I don't care. It came, it went, it wasn't (pardon the expression) repeated. As I recall, the SWA's objection was not with what they did, but with the use of the word "Islay" on a Speyside malt's label.
Almost all Ardbeg is matured in ex-JD, is it not? It's not even bourbon! The Scotch whisky industry does not make the distinction for that purpose.
As for finishing generally, if you don't like it, fine, don't buy it. But they put whisky into wood in the first place to improve it. If one barrel has not done the job to anyone's satisfaction, I see no ethical problem with using another to finish the job.