We call them dessert wines but the Australian term captures the glutinous sweetness of these wines better. Some people think that sweet wines must come from sweet grapes. They don’t. Let’s get the theoretical stuff over first.

All grapes contain sugar. During fermentation, yeasts convert that sugar into alcohol and so grape juice becomes wine. To make a sweet wine you can do one or two things: either you artificially stop the fermentation, usually by adding more alcohol which kills the yeasts (this is called fortification); and/or you make sure the grapes go into the fermentation containing more sugar than the yeast can cope with (either by picking the grapes late or by picking when ripe but leaving them out in the sun to become raisins).

What are the great stickies from around the world? To go back to Australia, stickies have been made in Rutherglen, North Victoria since the 1860s, using Muscat grapes dried in the sun before fermentation. The wine is then aged in oak barrels, using the solera system, like sherry. Old wine, which is concentrated by evaporation, is repeatedly added to younger wine, so that the age of the wine when sold is an average of all the casks that have contributed to it. So a ‘Rare’ Rutherglen may have wine in it that’s 105 years old, as well as wine that’s only 5 years old. It will be the most intensely flavoured wine you have ever tasted: raisins, nuts, figs – flavours so strong, so wonderful, that you’ll only manage a few sips before calling for a glass of water and a fan.

Spain has been producing ‘stickies’ for much longer than the Australians. Made with Pedro Ximénez grapes (known as PX) they too are left out in the sun to dry and age in the solera system. They haven’t quite the depth of the Rutherglen stickies but they are still a knockout. We’ve all drunk PX, of course, as Cream Sherry, which is PX mixed with dry fino. That’s like mixing Mozart and Wagner and playing them at the same time.

What about the sweet white wines of France? Wines from Sauternes and Monbazillac are late harvested, hence sweet, but in addition they are infected with ‘noble rot’, ie with the fungus botrytis, which gives them their distinctive flavour. Quite different are what the French call ‘vins doux naturels’, of which Muscat de Beaumes-de-Venise is the best-known. They are fortified with alcohol to stop fermentation and most of them are pretty dull compared to a Sauternes.

There are plenty of other great sweet wines and once you understand the principles you can soon see how individual wines are made: Spätlese wines in Germany are late harvested, as are Auslese, which are also infected with noble rot; Tokaji in Hungary is made in the same way as Sauternes except that the dried and rotten grapes are added to a vat of previously made ‘base’ wine for a second fermentation. And all along the Languedoc coast winemakers are making sweet reds with the Grenache grape, fortified with spirit. When to serve them? They go with strong cheeses, especially blue cheese, and with vanilla ice cream or sweet desserts. If you’ve any Christmas pudding left over, splash out on a Rutherglen sticky or a PX to serve with it. Life will never be the same again.

 Andrew Polmear