Thanks Glenn,
I did have heat in mind as a potential player here - nice to get it confirmed.
Since I come from a spirit background in Single Malts, I know the issue of heat/cold as a factor in maturing whisky.
Right now there's quite a discussion going on in the Whisky industry if temperature controlled warehousing affects the long term maturation of whisky.
Most 'traditionalists' of course (me included) think it's a bad thing, since the ups and downs in temperature makes the casks 'breathe' - the pores of the wood expand/pull together and with the releasing flavour to the whisky. This is very important since around 70% of taste in a whisky comes from the oak cask.
In American Whiskey (Bourbons/Ryes - note the spelling difference here) only fresh oak casks are used and whiskey here is actually know to rise in alc.vol% during maturation in the South US - mainly Kentucky. This ofcourse the because the spirit stored reaches such high temperatures, that the water evaporates faster than the spirit!! It's even know to give off a hissing from the casks matured all the way up just below the tin roof of the warehouse! Imagine that!
Anyway, enough rabling about this other hobby of mine - there are other forums for that, than this
Cheers,
Claus