Lets brew a sour beer with tropical fruit. That’s how the lastest collaboration brew at Honolulu Beerworks got started. When Beerworks Geoff Seideman learned that Ben Edmunds of Portland’s Breakside Brewery was coming to Honolulu and wanted to do a collab brew he instantly thought sour.

Seideman had good reason for wanted to brew his first sour with Ben, since he is one of the most knowledgable and successful brewers of bright, tart and vibrant lactobacillus based beers in the country. At Breakside, Edmunds has mastered the technique of kettle souring beer to crank out some amazing and incredibly affordable tart ales.

Edmunds was planning a non-working vacation to Oahu, but jumped at the chance to do a collaboration brew and work with two locally harvested fruits that are tough to come by in the Pacific Northwest. Fresh Maui grown pineapple was an obvious choice to complement the tartness from the lactobacillus. Edmunds was also intrigued by flavors of the calamansi fruit (a hybrid citrus and kumquat) and it’s a fruit that is readily available here in Hawaii.

Even though he was on vacation, Edmunds was up bright and early on the brew day to participate in the entire process. He also brought a secret weapon for the beer all the way from Portland…a full sixth barrel keg of Breakside’s house lactobacillus culture was shipped to Hawaii in advance of the brew day.

Once the mash was completed, the wort was transferred into the kettle where it was cooled down to 115 degrees. Unlike a normal brew where the beer would be boiled at this point, lactobacillus is pitched into the warm wort and allowed to work (create lactic acid…aka tartness) for about 48 hours. Lactobacillus thrive at warm temperatures close to 120 degrees and after 2 days the PH had dropped to the desired level (about 3.2). Edmunds explained that this is almost exactly the way they sour at Breakside, except for some differences in equipment.

A bit about this special lacto culture from Breakside. Edmunds mentioned that the original culture came from a commercial yeast lab, but over time they’ve noticed it develop unique tropical fruit flavors. I asked him about their process for making one of my favorite beers, Passionfruit Sour Ale, and he noted that a lot of the bright fruit flavors actually come from the lacto. They add a large amount of passionfruit to the finished beer, but according to Edmunds, most of the deep juicy fruitiness is already there. To showcase his point he poured a glass of the lactobacillus culture straight from the keg. The glass of bacteria filled wort smelled like a freshly opened can of pineapple juice and POG. It tasted like over ripened pineapples, deliciously fruity, tart and sweet all at the same time. I was shocked that lactobacillus could provide so much unique flavor on top of just acidity.

Back to the brew. A quick boil to add a few hops (2 IBUs worth), and then the hot wort was transferred through a hop back filled with pineapples and calamasi. The room instantly smelled like a fruit canning factory…it was intoxicating. At Breakside they don’t use a hop back so this was a unique addition to the brew. The wort then went off  to the fermentor. Edmunds had to rush off to the airport before the end of the brew day.

A final dose of more freshly pureed pineapples and calamansi were added to the beer after fermentation and constantly roused with CO2 to keep it in suspension. This is a technique that Edmunds passed along to Seideman. The real benefit of collaboration brewing is brewers sharing information, techniques and stories. Seideman, Edmunds and HBW assistant brewer Roxayne spent hours talking about everything from yeast management to brewery buyouts.

The final beer, named SideWork Sour Project, is unfiltered with a slight haze from both the absurd amounts of fruit and the wheat base. Light straw in color, it is bursting with ripe pineapple and tart citrus aromas. The aroma reminds me of those tiny cans of pineapple juice. The calamansi hits your tongue first. If you’ve never tasted a calamansi before imagine a tart key lime mixed with a sweet tangerine. Pineapple dominates from there with bright citrus notes and a wonderfully sweet touch. The tartness is mild and very approachable. A soft acidic bite cleans the palate and smoothes out all of the fruit flavors. At only 4.5% abv and 2 IBUs, it’s very easy drinking.

A few kegs will be headed to Breakside in Portland to go on tap there. A slice of paradise in the chilly PNW to remind Edmunds of his vacation.