A change in marketing strategy took place in the wine business about twenty years ago. Someone, somewhere had the bright idea of marketing wines by the variety of grape from which it was made, what are called 'varietals'. It has been a huge success - there can't be anyone left who drinks wine who hasn't heard of 'Chardonnay' or 'Cabernet Sauvignon'. In some cases that's all you'll get on the label - Chilean Merlot or Sauvignon Blanc from New Zealand. But a couple of conversations I've had recently started me wondering if this new classification of wines by varieties is really such a good thing.

Before I argue the case, it's worth remembering how the old system worked. Wines were labelled by their origin. Thus wines from Burgundy were called 'Burgundy' and wines from Bordeaux were called 'Bordeaux'. We recognised a particular style of wine because it came from an area that made wine in that style. With only the varietal name to go by you have no idea of what style of wine to expect. Just the word 'Merlot' on a label tells you little about a wine's style. It could be a jammy, fruity Merlot or it could be an austere classic style wine, there's simply no way to tell by the varietal name alone.

Worse, labelling by varietal leads to hopeless misunderstandings. Here are two comments I heard in the last month. 'I really dislike Chardonnay wines, what I really enjoy is a white Burgundy' and secondly 'I no longer like Merlot, what I like now is a good claret.' Do I need to tell you that white Burgundy has to be made of Chardonnay by law? That Merlot is a big part of most great clarets and some - like Chateau Petrus for instance, are made almost entirely from Merlot?

No one would seriously maintain that a wine-style like a classed growth Pomerol had anything in common with a Chilean Merlot, even though both wines are made from the same grape. The point is that grape varieties don't differ as much as say orange juice and apple juice. The differences are subtle and can be completely overwhelmed by the differences in the vinification. A heavily oaked Chardonnay from a hot climate like Australia won't taste much like a white Burgundy. If you taste a lot of different Chardonnays you'll see some similarity between them, but first impressions will tell you that the wines are very different.

In the old system you learnt to recognise the style - flinty, mineral Chablis; luscious and complex white Burgundy; fruity Beaujolais; big, robust Rhones - by remembering the origin. Only if you were a real anorak did you go asking what grape varieties it made from. All the information you needed was in the place name on the label.

Wine of the Week

Carmenere 2002 Reserva, Tarapaca, Chile.

Tarapaca make some wonderful wines and the Carmenere is an interesting example. The Carmenere grape, one of six legitimate grapes in Bordeaux, is now nearly impossible to find in there, although it's made a home for itself in Chile where the warmer climate suits it better. This estate bottled wine shows quite tannic, but decant it and chambre it and it's full of character and structure.

Available Superquinn. RRP. €8.69