@Whiskey_Hound Cheers..yeah it's pretty odd as other drams you generally get it up front. The bitterness I understand just not the reason it takes until you are well into the dram to show up and builds from there

@soba45 Nice review! Completely agreed on the creeping bitterness. It's generally not detectable until you've had a few pours from the bottle, but it definitely does show up in time

@cascode Ah interesting on SB. Also partially explains why they have issues with sulphur contamination in their sherried whiskeys. Wonder if it's them or the providers who cause that?

Interestingly, most Sherry is aged in north American white oak due to scarcity of European oak. As @cascode has stated, Macallan’s sherry oak offerings utilize Spanish oak, but they also introduce sherry and bourbon seasoned American oak with their double and triple cask series.

@Soba45 & @WhiskeyLonghorn As for GlenDronach, I don't have any information, but they have had a patchy history. The most important thing to remember with them, IMHO, is that all the great stuff they produced when the core lineup was revised in 2009 was blended from old stock produced in the 1990s when Allied Breweries was the owner. Billy Walker, although a *very* astute businessman and an excellent blender, had nothing whatsoever to do with actually making or maturing that stock - he just bought it along with the distillery. The real unsung heros of the lauded 12, 15 and 18 year old expressions were the distillery workers at the time and the head distiller.

@Soba45 & @WhiskeyLonghorn Springbank is a sort of special case. Distilleries that are owned by large conglomerates receive casks on consignment in big quantities - particularly so if the owner is a company like Beam Suntory that has direct access to their own ex-bourbon casks. There is generally little variation of cask type and when there is it becomes a core expression because they can continue to source in bulk. However small distilleries often obtain limited quantities of unusual casks from brokers and cooperages (have you noticed how many sassicaia cask finished whiskies suddenly appeared over the last few years, and that they all come from smaller distilleries?). Springbank buys their casks both on repeating contract and also in small one-off batches. They embrace batch variation and aren't afraid to take a leap of faith by filling half a dozen quirky barrels with spirit, waiting for 12 years to see what happens, and then releasing it as a one-off batch. It's one of the many reasons why I admire them. Oh, and by the way, a correction to my earlier post - Edrington didn't buy Macallan until about 2000, but the point about old casks and when they probably ran out is valid.

@Soba45 my thoughts exactly. I know that Springbank uses “wet” casks for some of their ageing. Maybe they have a special deal with a bodega. Maybe GlenDronach does too...? Their output is far less than Macallan so it’s not out of the question. Thanks to @cascode for the sherry info.

@cascode Ah very very interesting and deep thinking...I never would have put all those pieces together! I wonder how Glendronach's casking has been done and changes over time..

Also, the older style transport casks were filled with good quality sherry that was intended to be bottled for sale. Seasoned casks are not filled with sherry of this quality, and the "seasoning" sherry is re-used several times and then discarded because it is not of a quality that can be sold. In other words - second rate sherry.

Well, FWIW here's my 2c. Up until 1986 sherry was sold in the UK in transport casks, which were then re-purposed for whisky maturation. However in that year the Spanish changed their regulations so that sherry could only be exported in bottles. Overnight wet casks became much less common and distilleries started buying "seasoned" casks specifically made for maturation. It's safe to assume that a huge company like Edrington would have had significant stocks of old casks available back then so their supply probably didn't dwindle for another 5-10 years. If that's indeed the case it means that Macallan 18 (for example) matured in new-style seasoned casks would not have come onto the market until around 2010. Macallan uses Spanish oak rather than American and it lends a spicier, more tannic edge. It's not impossible that this bitter note has become more prominent now that seasoned casks are being used, as opposed to the old-style casks that were actually used for shipping and could on occasion contain sherry for longer than the 12 months that is typical for seasoning.

@cascode Huh interesting as i thought it was just me. I'm guessing the more expensive ones contain more older stock hence avoidingthe problem. I don't think they have changed their casking supplier so I wonder what causes it.

Interesting you mention that bitter aftertaste, I get it with almost every new Macallan. Old Macallans (I mean bottled more than 10 years ago) and the first batch run of the 1824 series are free of it, but it's showing up more and more.