Bottles of the same wine may taste very different, and variations increase as a wine gets older. In fact one bottle of a mature wine may be wonderful, and the next over-the-hill. Why?
Virtually all wine is a blend from different barrels or vats. If the mixing vat is not big enough to take all the wine, then one batch may well differ from the next. So, there may be a difference before the wine is even bottled.
A particular wine may be bottled in batches rather than all at the same time. The fill levels, added sulphur dioxide, entrained oxygen, and gas injected above the wine may all vary at each bottling session.
Historically this was always natural cork. It is a fine closure, but every cork is different and will allow differing amounts of air to diffuse through. This causes bottles to mature at different rates. One big advantage of screwcaps is that each closure is the same.
Transport and storage
This is a major issue, and can completely destroy a wine.
- Temperature – is covered in more detail by another post. If the temperature gets too high, the wine will be damaged, perhaps fatally. Cases of wine stored at different temperatures will mature at different rates.
- ‘Lightstrike’ – damage by over-exposure to UV light.
The larger the bottle, the more slowly and gracefully a wine matures. This may just be because the gap between the cork and the wine is the same for a half bottle, a bottle or a magnum. Any air in that gap will be spread more thinly in a magnum than a half bottle, meaning that it will be oxidised more slowly.
Age of the wine
The older a wine, the more time there is for all these influences to take effect, and the higher the chance of one bottle being very different to the next.