Parker Olen, co-owner of Mast Landing Brewing Company, with equipment for the brewery’s new Westbrook location, expected to open in late August. Chance Viles/ American Journal

WESTBROOK —  When Mast Landing Brewing Company opened its brewery and tasting room on Main Street in March 2016, the owners thought it would take up to 10 years to outgrow the space.

But the company is now looking to expand after only three years.

While the Mast Landing expansion is brewing, the owners are also excited to unveil their new beer in collaboration with alt-rock band Guster, just in time for the “On the Ocean” concert series at Thompson’s Point this weekend.

The exterior of the new Mast Landing brewery on Saco Street in Westbrook. Chance Viles/ American Journal

Aside from the collaboration, the real buzz for the brewers is the new operation at 600 Saco St.

“We needed to expand, but Westbrook has been incredible to us, so we wanted to stay within the city and this spot worked out,” Olen said. “It is definitely a much nicer place, with way more room.”

The new building on Saco Street, which will be the brewing and storage location of the top-selling beers, is now being finished, but some of the equipment is already in place, including new, 60-barrel beer tanks.

“This new building can fit about four of our old breweries in it,” Olen said.

These drums hold about 30 barrels of beer. Currently stored in the 920 Main St. location, these major beers will be moved to the expanded brewery. Chance Viles/American Journal

The company plans to keep 920 Main St. as a place to brew and store sour beers and wild beers, barrel-aging and the tasting room. The Saco Street site will hold and can the other beers.

The upgrade is expected to almost double the output of beer this year, from 4,300 barrels to almost 9,000.

“We want to thank the city, which has been supportive to us as a business,” Olen said.

The expansion will not be open and be operational until sometime towards the end of August, though the date is still being settled.

A new beer being brewed by Mast Landing in collaboration with Boston-based rock band Guster. The beer will be sold in stores and at the Guster show at Thompson’s point on Aug. 10. Chance Viles/ American Journal

In the meantime, Mast Landing is preparing to launch their collaborative pale ale with indie-rock band Guster for the second iteration of the “On the Ocean 2019: A Summertime Pale Ale,” beer.

“It’s a very drinkable ale that we hope will appeal to any beer drinker,” co-owner Parker Olen said. “It is citrusy and tropical, while not being too sweet or bitter.” The ale is set to be released Aug. 9, just before Guster is slated to play on Aug. 10. The beer will be available at the show.

“We actually went to see Dave Matthews Band a few years ago and met Adam (Gardner of Guster),” Olen said.

After talking, the brewers realized they were fans of the band, and the band loved their beer, so naturally, a collaboration was in order. This year marks the second annual reiteration of On the Ocean beer.

“It was really cool to work with them, since we both respect what each other does,” Olen said. “It did so well (last year), we knew we would be doing it again this year.”