A long time ago in the history of making wine a simple discovery was made; cleanliness made for a better wine. In an old-fashioned cellar that's not easy to achieve; the wind blows particles, insects and airborne bacteria around and taints and infections are hard to avoid. As more of the commercially produced wine that we buy is made in modern wineries, these problems are of little concern to the consumer. We expect to find clean, clear, stable wine in the bottles that we buy and by and large that's what we get.

The trouble with the sort of standardisation that this brings, is that little by little wines are losing their extremes of character. When I'm back in Italy and have the opportunity to taste locally produced wines it becomes clear to me; wines like these differ from their commercial counterparts precisely because of their variations. They are rarely mediocre, they tend to be either sublime or barely drinkable. For a single consumer like me that's not a problem, occasionally you're stunned by a wine and occasionally you furtively spit it out, but for a commercial concern it's a problem. Consistency is what a commercial winery strives for: occasional brilliance and occasional failure make a recipe for commercial failure.

If you can make your wine biologically stable, consistency of taste is within your grasp. Which is where sulphur came in. Sulphur was used to sterilise wooden vats where the wine was made; you burnt sulphur in the empty vat before you began to make the wine. It made sterilisation easier than the older method of firing the inside of the vat, but unless it's done carefully the taste of sulphur can get into the wine, which not only affects the taste, but many would claim is the source of headaches. Sulphur dioxide is used by most wineries, either during fermentation or before bottling to stabilise wines. Too much leaves a nasty taste.

On the other hand, tiny clear crystals that can form on the cork or in the bottle are not a defect. If you find these crystals in a bottle, which are formed from an association of potassium and tartaric acid, you've got a good wine. They only occur when very ripe grapes are vinified by a long fermentation process. Fast fermentation, which tends to happen in warm countries, doesn't produce this effect. Normally these tartaric crystals form in the wine barrel - shine a light into an empty one and you can see them glisten. But in slow fermentations they don't form in the barrel, but rather in the bottle - sometimes at the bottom, sometimes around the cork. If you find them, just pour the wine carefully rather than decanting, the crystals neither affect the colour or the taste of the wine.

Wine of the Week

Grillo, Feudo d'Elimi 2001

This is a varietal, the Grillo grape being used extensively in Western Sicily. It's a wine with intense floral notes and plenty of fruit and with enough flavour to accompany even spicy dishes.

Available Molloy's Off Licenses and Karwig Wines Carrigaline, RRP €10.10