Re: Consistency and standards
They change all the time. Whisky is an organic material, and as such, it abhors constants.
Surely, for blended brands, like JWB or for standard age expressions, such as Ardbeg 10, the goal of the blender/distiller, is often to maintain consistency through the years, but this is very difficult, as there are many variables in the distilling and ageing process.
For blenders, the formula probably varies even more as different distilleries offer up or refuse to offer up their wares for blending, as new distilleries open, old ones close and others are acquired by new owners.
For individual distillers, there is a variety of what is available at any given year, how many old stocks and young, as well as variance of flavor profiles that are going on in the various barrels they are blending to create the age statement expressions.
Everyone can think of their favorite whisky that used to be better or has improved over the years. Some are famous for inconsistency.