In 2013, Tobias Hahn and Nick Greiner met at the German American Society in Portland, where both had children in German language classes.[1] An hour later, they ran into each other at a brewing supply store, and discovered that they both wanted to make German-style beer.[2] Hahn grew up in Wiehre, Germany and studied microbiology at the University of Freiburg and wanted to bring traditional German beer to the United States.[3][4][5][6] Eventually, Hahn and Greiner founded Rosenstadt Brewery in 2015, making beer that follows the traditional Reinheitsgebot German purity law.[2][5][7] Rosenstadt does not have its own brewing facility or taproom, but has used other breweries' systems during down time.[2] At first they experimented at Max's Fanno Creek Brew Pub in Tigard, Oregon, where they developed a Kölsch which became one of their signature beers.[6][7] However, Max's Fanno Creek Brew Pub was not equipped for making German beer, so they had to find another facility.[6] Primarily, they make their beer at Estacada's Fearless Brewing.[6][7] They lager the beer at a storage facility.[2] "Rosenstadt" is German for "Rose City", one of Portland's nicknames.[2][4][8]
To sell their beer, Greiner and Hahn made cold calls to restaurants and bars.[2] After four years, Rosenstadt had nearly 300 accounts and made specialty beers for certain customers, including Clyde Common.[2][6][7] After its first full two years of production, Rosenstadt was one of the top 100 producers of beer in Oregon, based on volume.[2]
In 2017, Rosenstadt received the Gold Award for the Altbier at the Oregon Beer Awards.[4][9] In 2018, Olympia Provisions Public House rebranded to sell Alpine-themed food and drinks, and began selling seven Rosenstadt beers on tap.[2][6][10] The public house has served as a home base for the beer company.[2][11][7]
Rosenstadt later began bottling their beer.[5] In 2020, The Oregonian named Rosenstadt one of Portland's top 20 breweries.[1]