Bourbon and Scotch Storage
I was helping a friend move and she found a huge box of bourbon (Jim Beam, Marker's Mark, Knob Creek) and scotch (Black label Johnny Walker, Chivas, Royal Salute).
They were in the original boxes and then stored inside another box. The box was stored in her garage which of course went through lots of temp. changes, hot summer and cold winters for about five years in the LA area.
I checked a couple bottles and they all looked fine but we didn't drink any. So can the scotch and bourbon go bad in those type of conditions? Will they be safe to drink?
I got my eyes on the Royal Salute!!
Whiskey -- both bourbon and Scotch -- sealed and stored upright should be fine. They are high proof and very stable once bottled. However, unlike wine, they should never be stored on their sides, especially corked ones. Alcohol at high proof is a solvent, as in "able to dissolve" cork. And 'corked' whiskey, like corked wine, isn't gonna be like what you thought you had.
Should be fine, but watch out for the corks, if there are any. Corks dry out and break off, at times, when being removed. If a cork is dry and does not seal as well, the spirit should still be fine, provided no contaminant got into and past the cork. Nothing is going to rot a spirit, as nothing can live in it. Any bacteria would be killed off quickly.
I agree that these should be fine. Distilled spirits are very resilient. While extreme heat can harm flavor, basic temperature fluctuations like you are describing are unlikely to impact taste.
If you lived in Phoenix or Palm Springs, the answer might be different, but I have kept many Scotch and Bourbon bottles in my un-airconditioned LA house and have never had a problem.