A Two Harbors brewery is throwing a party Monday, but for longtime customers and employees, the cause for celebration is a bit somber.

The night of live music and cool brews will mark the last day Castle Danger can sell their refillable jugs, known as growlers. A state law prohibits breweries that produce more than 20,000 barrels per year — a milestone the North Shore beer maker surpassed in 2018 — from selling the 64-oz. jugs that allow patrons to take home their favorite drafts from the taproom.

“We’re really sad, and it’s going to be pretty tough,” said Maddy Stewart, Castle Danger’s marketing and events manager. The brewery is going to have to lay off one full-time employee and eliminate a handful of part-time positions in its taproom because of the loss of growler revenue.

But Castle Danger fans are hoping the Monday send-off is a temporary farewell — they even dubbed the event the “Growler Hiatus Hurrah.”

That’s because there’s a legislative battle brewing ahead of the upcoming session over Minnesota’s liquor laws. All weekend, Castle Danger will be encouraging those who visit their taproom to call their state legislator about supporting efforts to raise the growler cap.

Sen. Karin Housley, R-St. Mary’s Point, introduced a bill in February that would have allowed breweries producing up to 250,000 barrels to sell growlers. But the measure was never heard in the Commerce Committee, which is chaired by Sen. Gary Dahms, R-Redwood Falls.

The growler cap was installed as part of legislation to protect Minnesota’s three-tiered liquor system, which regulates the relationship between the three separate arms of the state’s industry — producers, distributors and retailers.

The three-tier model emerged after Prohibition, when lawmakers sought new ways to regulate liquor consumption that some felt had grown out of control in the pre-Prohibition era. Minnesota uses a modified version of the system, with a number of exceptions in place — including the fact that breweries are allowed to sell growlers at all.

Dahms said in an e-mail that he believes “common ground needs to be worked out by the players involved.” Lobbying groups have expressed concerns that raising the growler cap would come at the cost of small, independent liquor retailers.

“Until compromise can be reached between the parties, I believe current law is working quite well as evidenced by the incredible growth in the craft brewing industry,” Dahms said.

Housley has teamed up with breweries to launch a “save the growler” petition, which has received more than 10,000 signatures, and pledged to continue to push her bill when the Legislature resumes.

“Sometimes, the government needs to get out of the way to help create jobs and grow businesses,” Housley said.

As Castle Danger growler sales surge in their final days, other Minnesota breweries — like Indeed Brewing Co. in Minneapolis and Bent Paddle in Duluth — are creeping up on the 20,000-barrel annual production mark.

Stewart said Castle Danger lovers are mourning the loss of the growler culture — the quick beer stop in Two Harbors on the way up the North Shore — but hopes this weekend’s last hurrah will be a way to rally support for Housley’s bill.

“There’s nothing we can do about it. It’s happening,” she said. “Why cry over spilled beer?”