In Australia, for instance, a network of regional and national competitions are part of the agricultural show circuit in which pigs, sheep and cattle get as much of a look-in - although not in the same tent. The tasting panels are small, experienced and share a fair degree of unanimity.
The standard of judging is high, and a trophy at national level can be worth millions to the winning company. When Angas Brut, Yalumba's popular sparkling wine, won a gold medal at the Brisbane show, the company took out massive television advertising on the strength of it.
When it comes to judging, however, it must be remembered that wine-tasters are only human, with likes and dislikes, good moods and bad. While quality will usually out, character - a distinctive flavour or a subtle nuance of aroma - may be less likely to get a fair assessment. Fortune favours the bold. Alcohol, sugar and oak are seductive crowd pleasers, although the more experienced the judges, the sooner the obvious will be identified for what it is.
A canny merchant can gear entries to fit the competition. Jasper Morris, of Morris & Verdin, entered 19 wines in this year's International Wine Challenge; all of them received medals or commendations. He says: 'I chose the wines I expected to do well in this sort of competition. They are exuberant wines.'
The International Wine & Spirit Competition (IWSC) is the showpiece for the competitions that are held largely in English-speaking New World countries. A gold in the IWSC is a pat on the back for the company and its winemaker. But wines from one country, be it Australia or Canada, compete against each other rather than against the rest of the world, so its relevance to the consumer is limited.
Occasionally a result has an impact. When Chiltern Valley's 1986 Old Luxters won a trophy in 1987, it made a number of people (including me) wake up to the potential of English wine.
The International Wine Challenge, run by Wine magazine, makes no bones about its consumer orientation. Its relevance is recognised by the wine trade, which spends a fortune both on samples and on newspaper
What makes a Challenge medal so sought after? According to this year's preamble: 'No other competition is as tough. Just 25 per cent of the entries win medals compared with over 60 per cent for the IWSC.' What else? Medal winners are judged twice. And 'the Challenge judges are the best in the business'.
According to Robert Joseph, one of the principal organisers of the Challenge: 'Yes, we are bullish in saying we're the best, but we don't say we're the only competition. We exist because people who matter in the wine trade believe in us.'
This year the cream of the British wine trade and my humble self assembled in May at London's Chelsea Harbour. Wine was everywhere - 5,300 wines to blind taste - but not a drop to drink. Whereas it is normally my lot to end up on the low-alcohol section or medium Germanic whites, I managed to wangle my way on to some of the better tables once the elimination rounds were over.
First of all were reds from the increasingly popular merlot grape. Three gold medals in the awards announced on Thursday. Was this excessive? If so, we were all equally afflicted by generosity: gold for two New Zealand reds - Matua Valley 1989 and Delegat's Proprietor's Reserve 1990 - and a California merlot, Matanzas Creek 1989. Silvers went to two more Californians: Cuvaison 1989 and Shafer 1989.
Then chardonnay, ubiquitous, ever-popular chardonnay. Mostly New World chardonnay at first; the exuberant stuff. Gold to New Zealand's stunning 1990 Waipara Springs and a clutch of silver medals. To raised eyebrows, the highest of which seemed to belong to the store's buyer, Marks & Spencer's 1990 Chablis was awarded a gold at a nearby table.
This was a relief for France because our next table of chardonnays were white burgundies and, with one or two exceptions, offered half the excitement at twice the price. A Puligny Montrachet 1er cru (from Thierry Guyot) did manage a gold, however.
So was this mostly French subtlety overwhelmed by New World fruit? Up to a point, perhaps, although one or two of the burgundies were spoilt by winemaking faults, a feature which seems to apply far more generally to European wines than to those of the New World.
At last it was jackpot time. A table of top-flight bordeaux-style reds was followed by one of firstrate rhones. There were gold medals for Guenoc 1988 Cabernet Sauvignon from California, Parker Estate 1988 Coonawarra First Growth, and, to show there were no hard anti-Bordeaux feelings, Chateau Lascombes 1985. The chateauneufs were the least hard work. There was a gold for Andre Brunel's heady, spicy 1988 Chateauneuf-du-Pape (at Sainsbury's), and a sheaf of silvers, including, from Australia, Charles Malton's 1991 Nine Popes.
The rhone category was particularly strong this year. In all, the rhone-style wines did incredibly well, garnering 22 gold medals compared to three last year. By the end of my stint, I was ready for the low-alcohol section. Well, almost ready.