British beer is under threat from Irish cider. That worrying fact hung in the air over the carnival atmosphere in the Earls Court exhibition building in west London yesterday on day one of the Great British Beer Festival.
Real ale is a serious business in Britain. It defines a certain kind of Britishness, one which prizes the local, hangs on to tradition and does not snigger at names such as Goose Eye Barmpot. Real ale is brewed from the same set of ingredients as lager - hops, malted barley, yeast and water - but undergoes a second fermentation in the cask so it remains a live product.
Just what the organisers of this festival - the Campaign for Real Ale (Camra) - think of the Other Beer may be guessed from the T-shirts worn by the fleet of festival bar volunteers. Bearing a cartoon of a red-eyed hobgoblin, they simply state: "Not for Lagerboys."
"Actually, we welcome the kind of drinker who may have only experienced mass-market lager," says Camra's Owen Morris. "This is an opportunity for them to come down and try something different - but you won't find a pint of Carlsberg here, if that's what you're looking for."
The British Beer and Pub Association estimates there are some 500 craft brewers in the country, making the Great British Beer Festival less an opportunity for punters to get slaughtered than a showcase for beers only be available in a handful of local pubs.
Behind the vision of growth and diversity represented by the festival's serried racks of casks, each bearing its own printed label and thermal tea cosy, is an industry that is openly worried. Beer drinking has declined year- on year for more than a decade.
In 1995, 10.40 billion pints were consumed; in 2005, that had fallen to 10.13 billion. That still makes beer the market leader by a long shot, but brewers are keenly aware that wine consumption is increasing.
In 1960, just over one million hectolitres of wine were consumed in the UK; by last year, that number had soared to 13.8 million. Now, with wine taking 29 per cent of the market compared to beer's 43.1 per cent, it's beer's closest rival.
What's of even more concern to the brewers of Britain's milds, bitters, porters and stouts is the dramatic change in drinking habits. Ten years ago, just over half of all beer-drinkers opted for lager; now, after a decade of heavy advertising and, some would say, a lack of support for real ale from the big breweries, lager makes up nearly three-quarters of all beer sold.
"We're very worried," says Paul Jefferies, head brewer at Hyde's, a Manchester brewery that has been family-run since 1863. "A few years ago, we were hit by alcopops, which are now in decline, thank heavens, but now it's the Magners effect."
At this year's festival, there are mutterings about Magners cider, the English name for Bulmers cider, which was rolled out across Britain with a high-octane advertising campaign.
Last year, parent company C&C boasted of a jump of 130 per cent in UK cider sales, making it Britain's fastest-growing packaged cider.
It has also prompted rival cider manufacturers in Britain to imitate Magners pour-over- a-glass-of-ice approach, which seems to attract younger as well as female drinkers.
When I asked the bearded and bellied members of Skinners Sinners Singers (a pub choir sponsored by a local brewery in Cornwall), for their real ale recommendations, a gust of laughter went up. "Actually, love, we don't drink real ale. We're Guinness drinkers."
The Great British Beer Festival runs until Saturday.