At the funeral of their German-born grandfather Johann von Wolfhausen (Donald Sutherland), brothers Jan and Todd Wolfhouse (Paul Soter and Erik Stolhanske) discover that family tradition demands they travel to Munich during Oktoberfest to spread his ashes on the Theresienwiese.
In Munich the brothers unintentionally start a brawl that takes down an entire Oktoberfest tent. They participate in Beerfest, an underground drinking game tournament, run by Baron Wolfgang von Wolfhausen (JÃ¼rgen Prochnow), where they discover that the von Wolfhausens are related to the Wolfhouses. The German team reveals that Johann was a stable boy who stole the recipe for "the greatest beer in all ze world" decades ago and ran away with his prostitute mother, Gam Gam. Swearing to get revenge on the Germans, Jan and Todd return to Colorado, where they recruit college drinking friends for an American Beerfest team. Among them are: Barry Badrinath who is good at drinking games like Beer Pong and has since become a male prostitute, Steve "Fink" Finklestein who has a PhD in Chemistry, and Phil "Landfill" Krundle who has been known to drink copious amounts of beer.
During the team's year of drinking training, Jan and Todd find out their grandfather did not steal the family beer recipe, but was actually the rightful heir to the family brewery in Bavaria. The team uses the rediscovered recipe to brew Schnitzengiggle Beer, which is so good it literally makes them cry. After the German team receive a bottle of Schnitzengiggle in the mail, the Wolfhausen clan goes to America to take the recipe back. Their agent Cherry steals the receipe off Fink's computer, and drowns Landfill in a beer vat when he catches her. Thinking he committed suicide, the team decides to disband, but change their mind when Landfill's twin brother Gil joins. Like his brother, Gil has been known to drink copious amounts of beer and he even invites the other members of the team to call him "Landfill" in honor of his dead brother.
In Germany, the team uses an empty wooden keg as a Trojan Horse to get inside, where they emerge to boos and jeers. The Americans are allowed to participate after Jan and Todd show how uncannily they resemble the two Beerfest founders, thus convincing the crowd of their von Wolfhausen ancestry. In the finals (bootline chug), Cherry tells Gil at a crucial moment how his brother Phil died, causing Gil to crack and the Germans to win.
Jan offers the Germans a double or nothing opportunity. The Germans tell Jan they already have the recipe and thus no need for a rematch, but Fink points out that Cherry only stole a recipe for a low-carb strawberry beer, which prompts Wolfgang to have Cherry killed. When one of the von Wolfhausens knocks off Fink's yarmulke, he enters into a state of purely concentrated rage (the "Eye of the Jew") which allows him to coach the team to victory, barely gaining the win when the German team's anchor fails to finish "Das Boot" (Boot of beer).
In the post credits, the team go to Amsterdam to celebrate their victory in winning the brewery. Upon their travels they find Willie Nelson who is in need of a team for an international pot smoking contest.
Where does the team go to celebrate their victory in winning the brewery?
Amsterdam