LONDON (AFP) -- Grizzly-bearded ale swillers and well-groomed hipsters jostled for bar space Tuesday at the Great British Beer Festival -- with the latter group driving the U.K.’s craft beer boom.

The two tribes do not make for obvious bedfellows, but a love of traditional beer -- plus obscure facial hairstyles -- is more than enough to bring them together.

And though some hoary old-timers are quick to point out the difference between the new wave of craft beers beloved by hipsters and unpasteurized traditional real ale, most are embracing the fact that what was once seen as an uncool, so-called “old man’s drink” is now all the rage.

Around 50,000 beer lovers are expected to pour through the doors during the five-day festival which got underway Tuesday at the Olympia, an 1880s glass-roofed exhibition hall in London.

Festival organizers CAMRA -- the Campaign for Real Ale, which is on a membership high of 180,000 people -- are pleased to welcome new converts.

“I hope the craft beer movement isn’t a short-term zeitgeist. Hopefully people are not riding it just for a few years only,” CAMRA chairman Colin Valentine told AFP.

“Craft beer is a comparatively new term. It started in the United States about 10 years ago. There is no definition of it. Some of the big producers are now calling their beer craft ale.

“For us, real ale is what it’s all about. But if we’ve got people drinking and talking about beer, that’s a good thing.”

Battle of the beards

While craft beer generally covers small-scale breweries producing beer inspired by traditional British styles, real ale is defined by CAMRA as a natural product brewed using traditional ingredients and left to mature in the cask it is served from.

As opposed to beers artificially fizzed up with a blast of carbon dioxide, “it is this process which makes real ale unique amongst beers and develops the wonderful tastes and aromas which processed beers can never provide,” says the group.

Real ale’s market share of total beer sales in Britain plunged from 16.8 percent in 1980 to 7.2 percent in 2005, but was back at 8.2 percent in 2013. It now accounts for 15 to 20 percent of drinks sales in pubs.

Valentine said the trick was now to get young drinkers and women attracted by craft beer into real ale.

“‘Craft’ is a very easy thing to trip up on and get embroiled in pseudo-argument,” said Valentine.

“The CAMRA stereotypes -- late middle-aged, fat, bearded old men -- they’re here. But there’s a lot of young people at the festival.

“The hipsters with their ZZ Top beards -- we need to get them into the idea that drinking real ale is not just for festivals.

“People might want to see it as a battle between the two groups, but you’ll never hear me criticize people who like good beer,” he said.

Naked Ladies

British beers are known for their weird and wacky names and there were plenty of those among the 900 real ales, ciders, perries (made from pears) and international beers on offer at the festival.

Hop Smash, Bad Day at the Office, Dragonslayer, Screech Owl, Gravediggers Mild, Hit the Lip, Drunken Duck, My Darling Lemontime, Whakapapa, Swedish Blonde, Old Growler, Fruity Little Number, Good Spankin,’ Triple Chocoholic, Fugg Life, Naked Ladies and Crafty Stoat were all flowing from the pumps.

To soak up the booze, food to satisfy hoary ale fest veterans and hipsters alike was being served up, from traditional scotch eggs, pork scratchings and pickled eggs to olives, gourmet chorizo sandwiches and zebra burgers.

Some men tried to look stoical after sampling scorpion death chili chocolate, despite their sweating brows and watering eyes.