As Germany's brewers bid to have their purity law enshrined on UNESCO's list of Intangible Cultural Heritage, it seems that the influence of this historic rule - which stipulates only using water, malt, yeast, and hops in beer making - is shaping how beer is being consumed across Europe. And sticking to the rules doesn't mean you have to check your creativity at the door.

In Scotland's biggest city, Glasgow, the only brewery in the UK to make beer according to this law is having to build a second brewery to cope with the huge local demand.

West Brewery was started almost a decade ago by Petra Wetzel, 39, of Bavaria. She is a staunch believer in the so-called Reinheitsgebot, Germany's purity law for beer.

"I think it gives people a real belief that the quality of the beers we produce are like the best beers you can get in Germany and it's almost like a stamp of approval by the consumer that we can say that our beers are brewed in accordance with the purity law," she told DW.

Wetzel believes that West Brewery's ethos has educated many about beer's taste potential, and the craft beer scene which is now very big in the UK is promoting the smaller beers.

"We have a lot of young people who are very much following the UK and international craft beer scene, so they are much more adventurous with what they are drinking," explained Wetzel. "The younger audience is slightly more adventurous. And the lovely thing is that women are now becoming more adventurous with beer."

The brewery has just launched two new beers: a Weizenbock with seven-percent alcohol by volume and a steam beer that Wetzel says is a type of lager brewed with ale yeast.

Munich lager a favorite

Derek Hoy, 33, is one of the co-founders of Hippo Beers, Glasgow's first specialty beer store. He and his business partner, Alec Knox, set up their shop after becoming "frustrated" at not being able to find the beers they wanted to drink.

"The beer scene has grown since we started. Before, you had maybe a few bars that were known for selling cask ale but there was the emerging, more modern craft beer scene that we've seen coming up in the last three or four years," said Hoy.

Petra Wetzel is considering important her beer back to Germany

The German beers, especially the Munich lagers, are among the best-sellers at Hippo Beers, according to Hoy. "It's maybe a nice entry level for people to start drinking something different. If anyone asks for a lager recommendation, the first place we go to is the German section because nobody else does it better."

Hoy believes the purity laws matter more to what he calls "the hardened beer geeks" more than the general public. But he also says that you might be drinking more beer brewed according to the German purity law than you think.

"The thing about the modern craft beer scene is that the vast majority of the brewers will stick to the Reinheitsgebot anyway without saying that they do because the brewers are about keeping the beer pure and using the best ingredients," explained Hoy. "They don't necessarily say it; it's just one of those things that comes with being a good brewer."

Beer drinkers just want tasty beer

Craig Gibson, a beer enthusiast and writer for Glasgow's daily Evening Times' Pub Punter blog, says the trend towards craft beers in Glasgow may be growing, but that purity laws are not usually a factor in why people drink certain beers.

"People don't necessarily know about the German purity law but they know what beers they like," he summed up simply. "The Campaign for Real Ale's popularity and the fact you can get a variety of good beers in Wetherspoons (a large UK pub chain) shows how tastes are changing. There are literally hundreds of beers and ales available now in most bars - you don't have to look for them, but that hasn't always been the case."

Derek Hoy says people care more about good beer than about ingredient laws

The Campaign for Real Ale has become a popular movement in the UK, doing everything from promoting beer festivals to lobbying MPs on pub-related laws to monitoring trends. For the beer lovers behind the movement, it's not only the ingredients that are crucial, as with the German purity law, but also the brewing process.

"The vast majority of real ale in the UK is produced by microbreweries that can more easily experiment with different styles of beer and exciting new hop varieties," said Gibson. "This, combined with an increase in people drinking real ale, has led to an explosion in the variety of different beers available to drinkers - from hoppy Golden Ales and IPAs to rich, roasted Imperial Stouts and Porters - styles which were at one point on the brink of extinction."

Exporting German-inspired brews to Germany

West Bewery's beers are proving so popular, that after expansion it could even start exporting its brews - produced according to German purity laws - to Germany.

Petra Wetzel recalled her sending a keg of St. Mungo lager, West Brewery's house beer, to her parents' in Bavaria who were throwing a big party last summer. "The reception we got was outstanding," she said.

If the right partner came along, she added, she would be more than open to exporting her products to Germany. Wetzel's brewery is upping their capacity so much in 2014 that they would have the capacity to sell beer to many parts of the world that they previously wouldn't have imagined.

"So, for example, we've had an inquiry from India to sell Scottish premium lager to Mumbai and that is very exciting," said Wetzel.