A tractor-trailer bearing the Maine Beer Box squeezed between several old waterfront buildings at Marshall Wharf July 26, landing more or less on the doorstep of Marshall Wharf Brewing Co.

After making a full turn, a maneuver that took close to 30 minutes and required waiting for another tractor-trailer that was delivering cable to the local tugboat company, the refrigerated shipping container opened its doors, letting out a puff of cold condensation. Along one wall, a tangle of red and white hoses connected to 76 beer taps that later would be accessible outside the trailer through a row of hatches along the exterior wall.

Brewers from a half-dozen Midcoast craft breweries piled into the truck, stepping over pallets of 5-gallon beer kegs and moving others to the end of the refrigerated car to make space for their own kegs.

The custom trailer, a collaboration between Maine Brewers' Guild and Iceland-based shipping company Eimskip, had left Portland two days earlier and made its way to First Mile Brewing Co. in Fort Kent before rolling into the Midcoast.

By the time it returned to Portland, it would have made a dozen stops, collecting a wide sampling of the state's microbrews. The container will be loaded onto a cargo ship in Portland and carried across the Atlantic to England, where it will appear at the Leeds International Beer Festival in September.

In Belfast, the emissary big rig picked up a barrel's worth — six 5-gallon export kegs — from each of five Midcoast breweries, and the equivalent of five barrels from Marshall Wharf Brewing Co.

David Carlson of Marshall Wharf and Maine Brewers' Guild Executive Director Sean Sullivan conceived the Maine Beer Box idea in 2017 as a way to promote Maine as a destination in the growing phenomenon of beer tourism.

The tricked-out shipping container made its maiden voyage last year to Iceland, loaded with beer donated by Maine breweries, and returned with beer from Icelandic brewers. The island nation is home to Eimskip, has a growing beer scene and lies within vacationing distance of Maine, which made it a natural first outing.

England presents a bigger opportunity — but also a stiffer challenge — as many of Maine's best beers are inspired by their forebears in the British Isles. Accordingly, local brewers approached it with a certain amount of gamesmanship, and as it happened, a lot of brown beer.

Ben Hazen of Andrew's Brewing Co. in Lincolnville passed over his best-selling English Pale Ale in favor of second-best-selling Northern Brown Ale.

"I don't know how many people are going to send a brown ale to Leeds," he said. "I figured people would send IPAs. I wanted to be a little bit different."

Ethan Evangelos and Scott Bendtson of Threshers Brewing Co. in Searsmont also sent a brown ale that wasn't their top seller. In their case, it was a matter of keeping up with demand at their Searsmont location, though Evangelos was quick to point out that the brown ale wasn't swept up from the brewery floor.

"It's one of our better beers," he said. "It's just not one of the better sellers."

Danny McGovern, co-owner of two Midcoast breweries and a former head brewer for Marshall Wharf Brewing Co., made a similar prediction to Hazen's — that there would be glut of IPAs on the Beer Box. Rather than taking the double-bluff approach of sending a brown beer, he sent a Blueberry Sour from Lake St. George Brewing Co. in Liberty and a Citra Kolsch from island-based Monhegan Brewing Co.

Monhegan sent beer last year, but this would be the first trip abroad for Lake St. George. McGovern wagered the Maine Beer Box would set the state apart from all the other beer guilds around the country.

"Nobody's doing this," he said. "Nobody."

Carlson, of Marshall Wharf Brewing Co., sees the trip to the U.K. as a way to highlight the roots of Maine's relatively new brewing scene, generally attributed to David Geary brewing his own Pale Ale in the mid-1980s after studying with English and Scottish brewers.

Marshall Wharf Brewing Co. sent its 45 Cream Ale, Sherry Butt Marzen, ESB, Pemaquid Oyster Stout, and Phil Brown Ale. Asked about the absence of IPAs, a Marshall Wharf worker wagered they'd still be well-represented.

Next year, Maine Beer Box is expected to go to Norway. The goal, Carlson said, isn't to set up an export market for Maine beers, but to shine a light on what Maine brewers are doing today.

"It's kind of like showing up on someone's porch with a six-pack and saying, 'Hey, try my beer,'" he said.