Water, malt, hops and yeast.

Because of something called the “purity law,” those are the only four ingredients allowed in German beer. And so, unlike the more experimental nature of the American craft brew scene, German brewers tend to be purists. There’s a right way to make Pilsner, to make Oktoberfest, to make Kölsch. That’s why Marius Hartmann was so surprised when he first tasted Kellerweis, Sierra Nevada’s take on a traditional German Hefeweizen beer. As a Brewing and Beverage Technology student at University of Applied Science Weihenstephan-Triesdorf, Marius and his peers often sampled international pints.

“He didn’t know an American brewery could actually make a good Hefeweizen,” said Abe Kabakoff, the head pilot brewer at Sierra Nevada.

After realizing international work experience would set him apart from others in his program, Marius decided to work on his English. In 2014, he enrolled in a course at California State University, which is in the same city as Sierra Nevada. That’s when he met with Abe to discuss the possibility of an internship.

This is Sierra Nevada’s first time hosting an international intern through the J-1 Visa program. However, Abe is no stranger to the benefits of working abroad. It’s actually what brought him to a career in brewing beer in the first place. While in college, he opted to spend a year in Germany as part of the Congress-Bundestag Youth Exchange for Young Professionals.  Even though Abe was studying computer science at the time, he decided to mix things up by interning at a brewpub outside Munich. The brewmaster left during Abe’s internship, so for two weeks it was his sole responsibility to run the brewery.

“I don’t think I’d be in the brewing business if I hadn’t done that program,” said Abe.

While Marius’ internship at Sierra Nevada isn’t setting him on a new life path, it is opening his horizons to a different beer culture. At Sierra Nevada, they brew 3 to 4 different kinds of beer a week—a stark contrast from his home country, where they have 5 beer styles in total.

“America is 20 to 30 years ahead,” Marius said of U.S. brewing culture in terms of innovation and variety.

Since starting at Sierra Nevada, Marius has embraced the more experimental style of U.S. craft beer. During his stint at the pilot brewing part of Sierra Nevada, Marius created his own winter beer using spices like coriander, ginger, and nutmeg. He named it “Lebkuchen,” after the German equivalent of gingerbread.

“It was probably one of greatest experiences, because in past weeks and months I learned about the pilot brewery…and after 3 months I could make my own recipe,” said Marius.

The brew made it out to Sierra Nevada’s tasting room, where it was well-received.

“I never had the experience to brew with those ingredients,” he said “I’m happy it turned out how I wanted.”

This exchange program has been helpful for Sierra Nevada as well.  Marius’ other main internship project brought him back his native country. Abe tasked him with researching the proper German method to brewing a lager. Sierra Nevada wanted to see if there was a taste difference between their version, which was aged 18 days, and the traditional German one, which is aged for 4-5 weeks.

Through this project, the company learned that most people preferred the taste of the German method to theirs. “It’s a tool we can look at in the future and maybe adapt to,” he said.

Additionally, Sierra Nevada has something in common with the traditionalist style of German-brewing. They also like to stick to the same four ingredients required in German law. This way, they can avoid adding in unnatural ingredients. So for Abe, it was valuable to get Marius’ insight into how Germans approach Reinheitsgebot.

While Abe and Marius both appreciate experimental brews, they said they prefer a beer that is more drinkable.

“You can drink it all night long, but it’s not too boring,” Marius said about his ideal beer.

“The goal is you’d always want another pint,” said Abe. As a “company man,” he says he prefers Sierra Nevada’s Pale Ale.

Marius returns home at the end of January to continue studying. But he already thinks his internship will help him in the future.

“There’s no place you can gain more experience in 5 months than here at Sierra Nevada,” he said.