Boulder Beer Co. is marking 40 years in the craft beer world by downsizing its business in a significant way.

According to a post on its Facebook page, the Boulder, Colo.-based brewery is ceasing all packaging and distribution of its products and will instead be concentrating its efforts on producing beers exclusively for its existing brewpub on Wilderness Place. The decision to downsize its operations will “allow for continuing the brand onsite with more room for rotating experimental and specialty brews.”

“The craft beer world is changing,” reads a post on the brewery’s Facebook page. “We see an explosive number of new breweries opening every day, crowded shelves at retail, and we fight for share of mind with many of our distributor partners. We did not make this decision lightly, but rest assured, we will continue to bring you our best lineup of craft beers at the pub.”

Founded in 1979 by Alvin Nelson, David Hummer and Randolf Ware, Boulder Brewing was the state of Colorado’s first microbrew as well as the 43rd licensed brewery in the country. The company was renamed Boulder Beer Co. in 2005.

Although the brewery is discontinuing distribution if its beers outside of the brewpub, fans will still be able to purchase any of the brewery’s remaining packaged inventory through the end of the year.