Almost 65 years after allied planes flew western supplies into blockaded Berlin, a new American import is arriving by air: craft beer.

The beer is being flown in as part of a surge of German interest in American brewing, upending a centuries-old relationship in which German beer defined the golden standard for brewing and Americans emulated it.

Now, with craft brewers in the US capturing an ever-greater share of their home market, they are expanding in Germany as well. German consumers, intrigued by unfamiliar flavours, are purchasing more imported beer and are increasingly copying American efforts with their own small-scale brewing operations.

In the last year in Berlin, high-end US beer – including one from California that is flown over in coolers – has become available in some grocery stores, and several US-style craft breweries have opened. The efforts aim to challenge the dominance of plain old pilsner, the mild lager that dominates more than half of beer sales in Germany. Beer consumption is slipping in Germany, and some brewers say their only salvation lies in fostering a drinking culture less constrained by a 1516 purity law that they say crimps innovation.

"What we've found in the United States is this amazing variety of styles and the openness of customers to new things," said Marc Rauschmann, who is importing beer from California-based Firestone Walker Brewing Co in air-freighted coolers. Other beer is shipped by sea. "We were really impressed."

Rauschmann has started an aggressive effort to sell imported beer and to brew his own German beer in flavourful styles that are popular among craft brewers in the US but rare in Germany, such as hoppy ales and zesty lagers.

The turnaround is shaking big German brewers, many of whom like to brag that they are the best in the world. Upstarts are using another b-word, boring, to explain why consumption has been sliding from its 1976 heights. Back then, every person in Germany drank, on average, three litres of beer a week. Now it is down by a third and expected to keep dropping as older, beer-loving customers die away.

But unlike the US, where in recent years many supermarkets have expanded their beer selection to include dozens of styles from the far reaches of the globe, most German stores have remained resolutely unvaried, almost always offering just a handful of manufacturers and only rarely throwing a non-German beer into the mix.

Now Rauschmann and others are proselytising, travelling around Germany to spread the gospel of unusual tastes. His company, Braufactum, is owned by German beer giant Radeberger, which Rauschmann said was trying to help spark a new beer culture in the country where it has been a major producer since 1872.

For some beer businesspeople, that change can't happen fast enough.

"The German beer industry has to reinvent itself in a hurry, or it's going to be a small fraction of what it is now," said Eric Ottaway, the general manager of Brooklyn Brewery, which has been expanding in Europe and has been exporting its beer to Germany through Braufactum, which sells a 12-ounce (350ml) bottle of Brooklyn Lager in upscale grocery stores for the equivalent of $4.20 – almost three times its typical American price.

At a recent tasting in one Berlin bar, guests sipped craft beers out of special vessels shaped like wine glasses that helped concentrate the aromas of the brew. The bar was furnished in a decidedly Berlin style – it was a subterranean lair where beakers of bubbling fluorescent liquids served as decoration, the tables appeared to be made from welded-together car parts and fake stalactites hung from the ceiling – but the discussion was all west coast, about the virtues of various hops and of sour and fruity tastes that are foreign to German palates.

"It's easy to get decent beer in Germany. We call it boredom on a high level," said Dirk Hoplitschek, one of the attendees at the tasting. He started a beer-rating website in Berlin to try to stoke interest in non-German beer, hoping to spark a craft-brewing renaissance as happened in America in the late 1970s.

"The United States has a 30-year head start. People are traditional here. Maybe it'll be a bit slower, but it'll happen," he said.

For now, non-German beer remains a small part of the country's market – just 8.1% of sales by volume in 2012, according to preliminary estimates by the German Brewers Federation. But that is almost double 2004 levels, and it comes despite attitudes from many Germans, especially older ones, who remain dismissive of US beer.

"I have worked in pubs all my life, but never has anybody asked for an American beer," said Uwe Helmenstein, 52, a barkeeper in the middle-class Berlin neighbourhood of Friedenau.

"I don't think it would work here," he said, because perceptions run strong that American beers are flavourless and thin.

But with small-scale breweries springing up around Germany's cities, many of them creating beers that emulate American craft beer styles, the seeds of a broader shift may have been planted, some advocates say.

"The older people see beer as a daily nutrition. The younger people are more interested in different styles," said Thorsten Heiser, the head of exports at the Bavarian Weihenstephan brewery, which markets its beer-making origins in 1040 as the oldest in the world.

In the working-class Wedding neighbourhood of Berlin, one group of US beer enthusiasts is trying to create an outpost that sells styles that they missed drinking back home. They are building a small brewery and bar in the ground-floor storefront of a century-old apartment building, piecing it together with salvaged parts from other bars and breweries. Much of the brewing equipment is from the US, because it was cheaper.

"My friends would come to visit me in Berlin, and we would taste beer, and very quickly, I realised, we reached the end. We tasted all the styles," said Matt Walthall, 32, a part-time English teacher who is one of the three American expats behind the Vagabund Brauerei, whose storefront they plan to open in June.

"This was simply to fill a void," he said. "We feel as if we're teaching a lot of Germans things about their own beer culture that they've forgotten."

Washington Post correspondent Petra Krischok contributed to this report

• This article appeared in the Guardian Weekly, which incorporates material from the Washington Post