Old bottles of Madeira wine don’t have to be stored in an upright position, but unlike other wines, it won’t do them much harm.
Once wines have been bottled, oxygen becomes the enemy.
It oxidizes the wine, resulting in an unpleasant odor and taste. The purpose of the cork is to keep out all oxygen except the small amount in the neck of the bottle.
But because corks dry out and shrink, bottles stored upright will eventually let air in to oxidize the wine. Hence the typical advice to store wine bottles on their sides, keeping the cork moist.
Madeira wine, like sherry and port, is fortified by the addition of brandy before fermentation is complete.
This means some residual sugar remains in the wine because the increased alcohol concentration kills off the yeast. Another result of this process is, of course, to make a more alcoholic wine, usually between 16 and 20 percent by volume instead of between 10 and 13 percent.
This increased alcohol and sugar content tends to protect fortified wine from oxidation, so the danger is lessened.
However, some oxidation will still occur if oxygen is present.
Madeira, however, is a special case. It tastes better when it’s somewhat oxidized, a characteristic that was accidentally discovered and then deliberately exploited in the eighteenth century by shipping barrels of it on sailing vessels on long journeys through tropical regions.
Indeed, the term used for an oxidized dry wine is “maderized,” obviously derived from “Madeira.” Therefore, the risk of further maderization to a bottle of Madeira, from a dried-out cork, say, is not as serious as it would be with other wines.
Why, though, might upright storage be recommended?
Between 5 and 10 percent of wine corks rot when kept wet, and bottles sealed with those corks will eventually acquire the moldy smell of rotten cork. Such a bottle is called “corked” when it is opened and sampled, hence the routine of smelling the cork before pouring the wine.
If a bottle of Madeira is stored upright, the cork will never be wet and the bottle will never be corked. So if the risk of oxidation is considered a matter of little concern, and the risk of a moldy cork is a matter of greater concern, then the bottle should be stored upright. Of course, the very best solution would be to use only superior corks when bottling Madeira.
Will it still be drinkable centuries later? A couple of years ago we had the privilege of opening, decanting, and tasting about 2 ounces of an 1814 Madeira.
It was still drinkable, not fine, but drinkable nonetheless. It had been recorked every 25 years or so. In those days, Madeiras were often labeled with the name of the ship in which they were transported to the U.S.
Vintage Madeira is quite capable of outlasting its cork.
The practice therefore is to recork each bottle every few decades. A few shippers even list these recorking dates on their labels, in addition to the vintage date and the grape type.
The oxidized state of the wine allows the process to be carried out with a fair degree of confidence, whereas the same process applied to port, sherry, or an unfortified wine would risk spoiling the contents.
The process by which Madeira is deliberately allowed to oxidize, known as estufagem, was discovered by accident after barrels of wine that had been sent on the long journey across the tropics to the New World were found to take on a pleasant color and taste.
For centuries, producers continued to send out their Madeira in barrels to act as ballast for ships and to improve its flavor.
Now the barrels are simply kept at tropical temperatures of up to 120°F for about three months in the island lofts of the wine shippers.