Some time ago I saw an interesting discussion in Wine Talk about a blog entry from Tablas Creek that showed that heat causes water to expand, which can dislodge the cork, which damages the wine:
I am concerned about spirits also - since the alcohol is higher. I found that alcohol expands more - meaning there’s more risk of damage, atleast based on the considerations in the Tablas Creek post.
C F ethanol water
13 55.4 795.4 999.33
20 68 789.4 998.19
35 95 776.4 994.06
It’s true that the density of ethanol changes more with temperature than does water. Obviously that means higher risk of pushing a stopper out in high temperature conditions, particularly if there isn’t much air space in the bottle. My daughter recently had that happen when she tried to bring a bottle of gin home to me, and left it in her hot car. But I think most of assume some form of chemical heat damage to a spirit is much less to worry about, since spirits have typically been exposed to high heat during distillation.
Just make sure you don’t lay a bottle on its side for a prolonged period of time; I learned this lesson the hard way with a very nice bottle… The alcohol ate through the cork (which is supposedly different than a wine cork, as well) and then slowly leaked out the perforation in the foil cap.
It’s not just cork. I had a 200ml bottle of Johnnie Walker Gold that was a gift with purchase of JW Blue. The JW Gold bottle fell on its side unbeknownst to me. I didn’t discover this until several years later, when it began to leak thru the screw top metal capsule.
Screw caps are horrible whisky closures. Corks can degrade and leak or allow evaporation, as discussed above. I wrap all spirits bottles for long term storage with Parafilm and store upright in a cool dark space. It works on all types of closures.