There are some wines that never fail to give me a thrill, that always titillate my palate, that always leave me wanting more. They're the well-made dessert wines. I'm as happy with a Hungarian Tokaj as with a Tuscan Vin Santo, as thrilled to be drinking a good Muscat as a first growth of the Barsac or Sauternes. There's something about the intensity of flavour that comes from a Botrytis wine that's hard to better. It's a lingering taste can last in the mouth for ages after the last sip. I can remember an occasion when six of us were drinking a 1970 Chateau d'Yquem - which is a glass each - and an hour after I finished my glass, after more coffee and cigarettes, I could still taste the d'Yquem in my mouth. Remarkable.

Dessert wines are sweet, of course; the shrivelling effect of the botrytis concentrates the sugars, but they're not just sweet. In a good dessert wine there will be a balance between the sweetness and the acidity that is harmonious, plus there will be an explosion of tastes on the palate of concentrated grape essence. It's no accident that the very finest Tokaj is called Essencia, a name that gets added to other dessert wines as well, just to make the point that what you have is a concentrate - a distillation almost, of the very essence of the grape.

I've mentioned Tokaj because it was for years the drink of emperors, the favourite wine of the Hapsburgs. But there was an emperor who had other tastes; Napoleon Bonaparte liked Vin de Constance, as did Bismarck and Frederick the Great And when you learn that it comes from the Klein Constantia estate near Cape Town in South Africa, it's all the more surprising. It says something about nineteenth-century ideas of exile that Napoleon even had it shipped to him whilst he was imprisoned on St. Helena.

By the beginning of the twentieth century the Constantia estate was ruined as a result of the phylloxera beetle arriving in the Cape, but the legend of the wine praised by Dickens and Austen lived on. Since 1980 Klein Constantia estate has been redeveloped and once again the famous dessert wine was made. By carefully studying the old records the new owners have selected vines which are probably descendants of the original stock that was planted in Constantia 300 years ago, so a hundred years after its disappearance, the legendary wine is back again.

Wine of the Week

Vin de Constance 1997.

There's something pleasing about a wine as redolent of history as this. Even the shape of the bottle is nineteenth century, holding the equivalent of a standard half-bottle. Sip this wine from small glasses and delight in its intense flavours, let its perfume assail your nostrils and overwhelm your sensory apparatus. Powerful, heady stuff, that you can justify to yourself in this time of annual celebration.

Available Greenacres Wexford and selected off-licenses in Dublin. RRP €34.95