Lawrence wrote: "People are drinking less sherry these days and as a result the caks are not available. "
I don't think people are drinking less sherry in the UK - my experience (drinking with friends, especially female friends) is the opposite, and this story seems to back it up:
I don't know how that affects availabilty of sherry casks in the UK.
However, to be honest, I don't really care much for Macallan any more. Since the transfer of ownership, Macallan has changed dramatically in the way it deals with its customers. I don't like what they do, and I don't trust a word that the Mac pr and marketing people people say. Credibility went out the window when they began defending the indefensible - denying the truth of the story re the "Fake Mac" (which they were selling on their website!) for months after the world knew the truth.
The Mac "vintages" and special bottlings are overpriced, and the brand is trading on a reputation built up long ago when it was a truly distinctive dram, owned by an independent company of recognised integrity.
Many folks say that the demand for Mac was such that most of it came from "treated" casks anyway, in which case the non-availability of large numbers of casks that had previously been entirely filled with sherry would not have been a problem.
And I'm certainly not implying that Mac was alone in treating casks with paxarette (allegedly) - it's an "old hat" issue here on the forum, and I think most folks agreed that the important issue was how the resulting whisky tasted.