杏吧原创

Indestructible wine

I鈥檝e just returned from a holiday in Madeira. I learned that old bottles of Madeira wine 鈥� a fortified wine similar to port and sherry 鈥� should be stored in an upright position. Bottles stored in this way are still drinkable centuries later. However, most other bottles of wine should be stored lying down to keep the cork moist and intact. Why is Madeira different, surely its cork will dry out too?

鈥� 鈥淥ld bottles of Madeira wine鈥� don鈥檛 have to be stored in an upright position (as below), but unlike other wines, it won鈥檛 do them much harm.

Once wines have been bottled, oxygen becomes the enemy. It oxidises the wine, resulting in an unpleasant odour 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 oxidise 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 per cent by volume instead of between 10 and 13 per cent).

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鈥檚 somewhat oxidised, a characteristic that was accidentally discovered and then deliberately exploited in the 18th century by shipping barrels of it on sailing vessels on long journeys through tropical regions. Indeed, the term used for an oxidised dry wine is 鈥渕aderised鈥�, obviously derived from 鈥淢adeira鈥�. Therefore, the risk of further maderisation to a bottle of Madeira 鈥� from a dried-out cork, say 鈥� is not as serious as it would be with other wines.

Why, though, might upright storage be recommended? Between 5 and 10 per cent of wine corks rot when kept wet, and bottles sealed with those corks will eventually acquire the mouldy smell of rotten cork. Such a bottle is called 鈥渃orked鈥� 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 mouldy 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 I had the privilege of opening, decanting and tasting about 50 millilitres of an 1814 Madeira. It was still drinkable 鈥� not fine, but drinkable nonetheless. It had been recorked every 25 years or so. Its name was 鈥淰iolet鈥�, the same as my wife, so I kept the bottle. In those days, Madeiras were often labelled with the name of the ship in which they were transported to the US.

Edward Hobbs

Wine consultant

Wellesley College, Massachusetts

鈥� 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 oxidised 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 oxidise, 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 colour and taste.

For centuries, producers continued to send out their Madeira in barrels to act as ballast for ships and to improve its flavour. Now the barrels are simply kept at tropical temperatures of up to 50 掳C for about three months in the island lofts of the wine shippers.

Mark McKegrow

Cheltenham, Gloucestershire

This week鈥檚 questions

Pingu鈥檚 pleasure

Why is it colder at the South Pole than at the North Pole?

T. P. Ladd

Mirfield, West Yorkshire

Hail the ale

When Britain ruled India, brewers developed a special type of beer known as India pale ale that, after being brewed in Britain, could withstand crossing the equator twice before arriving in India still in a drinkable condition. This was in the days before beer could be pasteurised and filtered, and so it was heavily hopped to keep it in good shape. What are the properties of hops that help them to preserve beer?

B. Manders

Northchurch, Hertfordshire