Novel passion projects in the beer world tend to have charming backstories associated with their birth.

Take, for instance, the story of how Tree Beer, the brand new Blue Hills Brewery offering, came about. And if you ask Dave Tree, band member of legendary Boston hardcore group Tree, it comes down to a fateful day at a preschool bus stop.

“My brother’s son has a buddy at preschool, and that kid’s father shows up one day to drop off his kid while wearing a Tree t-shirt,” says Tree. “My brother says, ‘Hey, that’s my brother’s band,’ and the guy turns out to work for Blue Hills Brewery, and I called him that day and was in the brewery by end of week.”

That Blue Hills Brewery employee turned out to be Jim O’Neil, director of operations for the brewery, who was keen to chat about what kind of beer they would potentially collaborate on. If a Tree beer was going to exist, named after the band, the two of them wanted to make sure it was something they both liked and could stand behind as both craft beer aficionados and general beer drinkers.

“I always wanted to do a beer with a band,” says O’Neil. “Smuttynose did a beer with Scissorfight out of Portsmouth, NH. Many people have asked me when we’re doing a beer with a band, [so] maybe it was fate I had my Tree shirt on that day.”

And now that Tree and O’Neil have spent the last month working on the project, with an earlier iteration coming out with a massive 8 percent APV (“I wanted to make it 9 percent and bars were like, “9 percent beer? I don’t know dude…’”), they’ve come up with a Kolsch-style brew that’s a tweaked spin on a previous version Blue Hills Brewery had been making. After Tree conducted taste tests and even had some sample trial kegs at a few recent art shows (Tree’s artistry and design eye graces the logo and label for the beer itself), the two brought the APV down while still keeping some punch (7.5 percent) and tweaked the recipe, resulting in a Kolsch flavor profile with a light, hoppy finish.

“We don’t want to trick people; we had a taste-testing here in the art gallery after we got the tester keg, and everyone liked the high APV, but a lot of people wanted to bring down the APV and the hops,” says Tree. “The brewery wanted that too. I’m not normally in the [brewing] seat, but it’s nice to be on both sides of the keg now. We tried to design a beer that’s for the masses but still a craft beer.”

Tree and his new band See This World will be performing at the annual Boston Freedom Rally on Boston Common this weekend, where kegs of Tree Beer will be on-site for people to try out the new brew firsthand. Additionally, O’Neil says he’s working through Tree’s connections at local bars and art shows, but after the Freedom Rally there will be kegs going into local bars throughout the Boston, Cambridge, Somerville, and Allston/Brighton areas during October and November. If things go well, the brewery will plan to start bottling it as well.

“People may buy for the novelty at first, should they remember my band Tree,” says Tree. “But after that they’ll buy for the taste. And they’ll like it.”

TREE BEER. TASTE IT AT THE 26TH ANNUAL BOSTON FREEDOM RALLY ON BOSTON COMMON 9.26-27. BLUEHILLSBREWERY.COM