Why do we care so much about temperature when it comes to wine
Wine storage is one of those topics that sounds boring right up until the moment you lose a great bottle to heat damage. Then it suddenly becomes very important, very quickly. Temperature is not just a minor detail in wine storage, it is one of the most critical factors in whether a bottle ages gracefully or ends up completely ruined.
What heat does inside the bottle
When a wine bottle overheats, everything inside it expands. That sounds simple, but the consequences can be brutal. Wine is mostly water and alcohol, and both expand as temperature rises. Even a relatively small increase in temperature can create a surprising amount of pressure inside a sealed bottle. This is happening silently, slowly, and often without any visible warning at first.
The role of gas and pressure
Then there is the gas. Every bottle has a small pocket of air between the wine and the cork. Gas expands far more aggressively than liquid when heated, so as the temperature climbs, internal pressure ramps up fast. This pressure builds from the inside out, and once it starts increasing, it does not stop gently.
That pressure has only one place to go.
Glass does not move. Cork does.
When the seal starts to fail
As internal pressure rises, the cork becomes the weak point. Natural cork is elastic up to a point. It can compress and rebound, which is part of why it has worked so well for centuries. But sustained heat weakens cork over time. Its grip on the glass softens, friction reduces, and the seal that once held firm begins to loosen.
At first the movement can be tiny. A millimetre or two is all it takes. Sometimes you will not even notice it unless you are really looking. But once the cork shifts, the damage has begun. Oxygen starts to creep into the bottle. Wine can begin to leak out slowly. Oxidation accelerates, stripping away freshness and energy from the wine far earlier than intended.
How heat damage shows itself in the glass
This is why heat damage often shows itself as pushed corks, sticky residue on the neck, or wines that taste tired and flat. Aromas can become muted or cooked. Fruit character loses its shape. Acidity feels dull rather than refreshing. It is not subtle when it finally reveals itself in the glass.
What you really lose when a bottle is damaged
What makes this especially painful is that you are not just losing a bottle. You are destroying years or decades of work from a grower and a winemaker, along with the time you spent cellaring it and the money you invested in it. Few things hurt more than opening a special bottle only to realise it never stood a chance.
Stability matters more than perfection
The good news is that wine does not demand perfection. You do not need laboratory conditions or a cellar locked permanently at twelve degrees. What wine truly hates is instability. Rapid temperature changes, repeated spikes of heat, and constant fluctuations will do far more damage than a steady temperature that sits a little warmer than ideal.
Consistency is everything. Keep bottles cool, keep them out of heat, and avoid sudden changes wherever possible. Control temperature during storage, transport, and delivery, because damage often happens long before a bottle ever reaches your cellar.
A final reminder
Wine is patient. Storage should be too. Now that I have experienced this with a bottle of my favourite Raveneau it’s even more important to me.