Everything to Know About This Brand New Brewery in Bay View

Rob Brennan’s small brewery Supermoon Beer Co. will focus on wild beers and eventually a small taproom with classic European styles.

When Rob Brennan talks about the beer that’s almost ready to come out of Supermoon Beer Co., his tiny brewery in Bay View, two common threads run through it: He wants to make beer that carries a sense of place and time.

The place, in shorthand, is 3145 S. Howell Ave., a general-store-looking building that’s been a lot of things over its 120-odd years but was most recently a home base for a seamstress. 

There, Brennan (and almost entirely Brennan alone) is building out a small taproom that will be the public face of Supermoon Beer when it’s feasible to have a small taproom again. There’s a small brewery in the back.

And the sense of time will be innate to the beer. Brennan is planning to focus on producing mixed- and spontaneous-fermentation and wild beers that take months of fermenting in wood barrels to unlock the funky and sour/tart flavors and aromas that make beer geeks covet them so.

Rob Brennan doesn’t have a set date for opening the Supermoon Beer Co. taproom in the front of his building at 3145 S. Howell Ave. Photo by Chris Drosner


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And that time, well, it’s almost up. These beers need to be blended and bottled when they’re just right, and that microbiological Goldilocks zone came last weekend. COVID-19 derailed his pre-pandemic plans, obviously, but Brennan is now planning his first bottle release for this fall, around Thanksgiving. Those beers – and the microfauna they host – are now sitting in big wooden barrels in the brewery. “They are ready,” he says. “They don’t care that there’s a pandemic happening.” 

But back to the place. More important to Brennan than the Supermoon building itself is the quiet and homey neighborhood around Humboldt Park, one of those cool Milwaukee neighborhoods where small businesses are interspersed with houses. The block of Howell containing Supermoon includes a bunch of tidy homes, The Bubbler bar, a liquor store, a church and the Minnesota Leeches bait shop.

“There are gems all over this city,” Brennan says. “Bay View is an extremely special place as well, with many of its own. I was heartbroken when the Palm Tavern closed up because it embodied the best parts about exploring flavorful beer – rock-bottom pretense, cozy and welcoming, and a balance to their menu that felt fun, yet sensible for a neighborhood spot. I hope I can bring some level of that experience to our little corner of Bay View.”

All of Supermoon Beer Co.’s output so far is aging in these 12 wooden barrels – mostly used wine barrels. Photo by Chris Drosner

It’s a place where it’s easy to feel like you’re at home, and that was the vibe that drew in the Chicago native and his wife, Maria Keegan, an Appleton native. The couple, both 35, were familiar with Milwaukee, meeting as students at Marquette University. A visit to Keegan’s brother in Bay View a few years ago sealed the notion that they would move back to Milwaukee, which they did in September 2018 when she got a job with Aurora Health Care. 

Brennan is a longtime tinkerer and builder, and in his early 20s that energy found an outlet in homebrewing. He met Eric Hobbs and Tom Korder before they launched Penrose Brewing in Geneva, Illinois, getting a firsthand view of what it takes to open a brewery. He joined that team and eventually became sales manager, a post he manned for four years. Since the move to Milwaukee, he’s worked an advertising job.

Brennan knew he wanted to start very small, buying the building first and building nearly everything but the brewery equipment themselves on nights and weekends. The advantages of that approach  – slow, steady and small – became evident when the pandemic sucked the air out of the hospitality industry they were working to join. Supermoon had no employees to lay off, no rent to make. The urgency of finishing the service part of the taproom abated as it became clear it would be months before such an operation could be sustainable. “When the taproom opens, it will be small,” he says. “I’ve never been more thankful to have taken the pace and scale that I have.”

The Supermoon Beer Co. logo is on a tote used to transport wort brewed elsewhere to the tiny Bay View brewery. Photo by Chris Drosner

The plan for that taproom – now pushed back until the pandemic allows – is to pour mostly “clean” beers produced on the two-barrel brewery as a complement to the wild ales and lagers Brennan believes will make the Supermoon name. From a business perspective, these beers can go on tap as soon as 10-14 days after brew day, while the mixed-ferm and wild beers will require several months to produce. 

Don’t expect big pastry stouts and milkshake IPAs. Brennan describes his brewing interests as lying in sessionable (low ABV) European styles with American influences. In short: restraint, drinkability and “beer that tastes like beer.” One house beer he’s been working on is Yarn, an unfiltered lager he’s hoping will become something like a “house beer.” “While the first beers we’re releasing are on the funkier side of things, it’s important to me that we keep our offerings balanced,” he says.  

The funkier side of things, though, is where Brennan’s passion lies. He describes the various beers aging in the dozen or so (mostly wine) barrels as a “library of flavors” that he will carefully blend to arrive at a final product. Most of the wort – that’s beer that’s just been brewed, before it’s fermented – was made at Enlightened Brewing and schlepped over to Supermoon in a 10-barrel tote that looks a little like a giant milk jug. One batch on the bigger and more efficient brewhouse at Enlightened can fill three to five of his 60-gallon wine barrels.

Photo by Chris Drosner

The flavors and aromas of the beer inside the barrels are shaped by yeast, bacteria and other microorganisms that give off varying compounds that can evolve, often dramatically, based on the beer’s dynamic environment.     

Each barrel’s product has its own character, so last weekend Brennan blended the beer in certain barrels together to achieve the profile he’s looking for – a combination of acidity, funk, sweetness, bitterness, mouthfeel and other factors. It’s a method used by many of the great lambic brewers in Belgium. That’s an influence that becomes clear as Brennan pulled out a bottle of gueuze from legendary brewer Cantillon during our conversation last month.

The debut Supermoon drop this fall – Brennan plans to release bottles four times a year, eventually – will consist of three beers. The 500-milliliter bottles will cost $10-$14.

Supermoon Beer Co.’s “clean” beers will eventually be made on this tiny two-barrel brewing system in the back of its building on South Howell Avenue. Photo by Chris Drosner

Many Phases is the first in what’s planned as a long series of mixed-fermentation, barrel-fermented farmhouse ales. They’ll have a common thread but vary slightly from release to release as Brennan plays with subtle variations. The first will be a blend of 12- and 14-month-old rustic farmhouse beers. 

Brennan describes the beer called Oaxen as a love letter to the classic funky Belgian pale ale Orval. This beer is a lager brewed with spelt that’s then refermented with Brettanomyces bruxellensis, a “wild” yeast that Brennan hopes to approximate Orval’s unique funk character.

Capping the debut release is Deus Ex Forager, a blend of 11-month and 9-month golden ale refermented with a copious amount of Door County cherries (100 pounds per barrel). 

“I brewed my first beer about 12 years ago and opening my own small brewery is something I can honestly say I’ve thought about at least once a day since then,” Brennan says. “The fact that we’re in arm’s reach of bringing that dream to fruition is absolutely wild to think about, and I’m thrilled for it. … I’m proud of the beers, and I hope they add something fun to the vibrant beer scene here in town.”



Executive editor, Milwaukee Magazine. Aficionado of news, sports and beer. Dog and cat guy. (Yes, both.)