I was wondering if the whisky in the miniature bottles degrades over time. I was considering buying some old bottles to drink and I wanted to make sure that they would still be drinkable. I have a miniature bottle of Macallan "Private Eye" and I'm thinking about trying it as well but I want to make sure it is a good representation of the 70cl bottle of Private Eye.
Spookily i just posted something on the evaporation poll relating to this. Have no fear down to the top of the label for cask strength and just below the shoulders for standard strength. I've had some stunning whiskies some of which have been in the bottle for 30 years.
Mini's seem to evaporate more quickly than regular bottles so I would be careful if you have one that is half evapourated as the contents may not be a true reflection of the actual whiskey due to possible degradation. However as long as you don't pay through the nose for them I reckon it would be no harm. You never know until you taste and at the end of the day it won't kill you so go on give it a go.
It really is down to the cap/cork and bottle top. Some mini's have great caps and they are not an issue but in general thes caps on mini's have a lot to be desired.
An educated guess is that the small area that the Mini cap covers is too insufficient to create a good seal for long term storage. Have a good look at the cap and bottle neck of a Mini in comparison to a regular bottle. The thread on the bottle neck of a larger bottle and the cap is much deeper.
However if you look at sample bottles that LFW have these are great for storing whisky.