Originally Posted by Islay Peat
Thanks for the excellent reply and I guess it then goes that when a master blender retires then the next one may end up making choices, for any number of reasons, which may or may not affect the overall flavor of a whisky.
I don't know what that one bottle of Glenfiddich 12 tastes like other than I was surprised to like it so well when every other experience had taught me that I didn't care for it. I do think that particular bottle is over 15 years old due to the time frame of my friends death and the different appearance of the box and label. I know none of that should affect the flavor, which is why I became curious as to what else could explain the difference in flavor.
There are certain changes in the labeling, usually subtle, that might occur over time for a given product.
The 'older' 12 yr that your friend had - what were the storage conditions, was the bottle exposed to sunlight for a period of time[direct sun], what was the level in the bottle[oxidation], was the bottle kept on its side exposed to the cork? All of these can have an effect on the spirit.
One other thought - when distillery's blender retires or unfortunately passes away his or her sucessor has most likely been an 'apprentice' if you will and has or should have a pretty damn good idea what a particular 'blend' should taste like to the buying public. The last thing a distillery would want is a 'off' blend that would alienate their buyers.