The definition of “craft beer’’ is an infinitely evolving phenomenon and with new commercial breweries opening every day in the United States, there seem to be countless manifestations of every style, flavor, and philosophy. But choice and quality are two of the main reasons why we’re in the throes of a beer revolution that has swelled far beyond the borders of early American pioneers like Jim Koch, Greg Noonan, and Rich Doyle and Dan Kenary at Harpoon. After speaking with several local brewers by phone, here’s a look at the fresh faces and underexposed gems that are the future in a region that continues to be at the forefront of an exclusive, visionary fraternity.

Jack’s Abby Brewing This two-year old Framingham brewery defies categorization. “We actually got into the Great American Beer Fest this year and we were trying to submit beers for medal consideration,’’ says owner Jack Hendler. “We realized that we didn’t have a single beer that fit into a traditional category.’’ After studying at beer schools in Chicago and Munich, Hendler began his professional career at Beer Works on Canal Street, but left after six years for a more intimate endeavor with his two brothers. Specializing in hopped-up lagers, such as their signature Hoponius Union, and smoky black numbers like their Fire in the Ham and Smoke & Dagger, the Hendler clan has pushed craft beer in a refreshing new direction. “We saw people pushing the boundaries with ales, doing some really unique and creative things, and we asked the question, Why don’t people do this with lagers?’’ Most of the hops in Jack’s Abby are grown on the Hendler family farm in Connecticut. They even include their parents’ pumpkin and squash harvests in their autumn seasonal, Mom & Pop’s Pumpkin Crop. In the future, Hendler says he expects to release some interesting concoctions using the fruit trees on their property and maybe even a spicy beer or two. Just don’t expect the status quo out of Massachusetts’ most talented brewing family.

Trillium Brewing Sensitive to the long lines that accumulate for growler fills at their booming Fort Point brewery, Jean-Claude and Esther Tetreault have already added days and hours to their fledgling labor of love. Besides the demands of a thirsty public and a waitlist of restaurants and bars clamoring for product, Jean-Claude has the needs of an infant, a toddler, and a desk job in Lexington. “When we’re not eating or sleeping, and sometimes even then, we’re working on the brewery.’’ Building off the success of their flagship saison, Trillium is now churning out a series of exceptional beers like their Little Rooster, an American pale ale with citrusy pine and a welcome rusticity and their Wakerobin, a farmhouse red brewed with rye and earthy nuggest hops. The Tetreaults obsession with everything Trappist is soon to yield wild yeast sours and barrel-aged elixirs to their growing reputation as Belgo-American wunderkinds. A bottling line is currently in the works to fill 750 ml bottles for retail and the Tetreaults are even searching for new real estate for what they’ve deemed “Phase 2’’ of their craft existence: a spacious second location to alleviate their production woes. Jean-Claude credits the “sobering’’ advice of Pretty Things’s Dann Paquette with launching the object of his “hopes, dreams, and aspirations.’’ Now Trillium is well on its way to building their own status as fellow icons of the Massachusetts beer scene.

Notch Brewing “There was a lot of people telling me, you won’t make it,’’ says Notch owner Chris Lohring. “Session beers? That’s going to fall on deaf ears. And after the first year it looked like it would be that way, but this year has proven that people have really come around.’’ Inspired by the nuanced lagers of the Czech Republic, Lohring’s low-alcohol pilsners and pale ales were initially pitted against the public’s fixation with boozy imperial stouts and escalating levels of IBUs — not to mention the damning reputation of mass-produced lagers. Now business is booming thanks to beers like their American Session Ale and Left of the Dial IPA, drinkable brews with as much complexity as their high-octane counterparts. Next up for Lohring? Battling the dogmatic misconceptions that have hovered around corn adjuncts. “We have antiquated notions of what craft beer is compared to the rest of the market. Craft brewers are heralded and celebrated for using any ingredient under the sun, but for some reasons corn and rice can’t be involved, and I just find that misleading. Corn is the most traditional ingredient in US brewing.’’ Expect The Mule, an American corn lager, made with local heirloom varieties from Western Massachusetts, to hit retail shops and bars later in August.

Brash Brewing Ben Fullelove is the owner of the best craft beer bar in Texas, the Petrol Station in Houston. But when state law prevented him from contributing his own recipes to the field of extreme beers, he took his ambitions to Ipswich on the advice of his friends at Clown Shoes. Now, splitting time between Houston and his adopted home at the Mercury Brewing Co., Fullelove turns out outrageous contract brews like his Texas Exile, an imperial porter that has an addition of cold-brewed Barismo coffee and their Cold Ass Honky, a farmhouse saison, dry-hopped with massive amounts of Amarillo hops.

Newburyport Brewing Chris Webb and Bill Fisher are truly an overnight success story. Two normal guys with day jobs and a passion for homebrewing and music (they play in an eight-piece funk band), they whimsically decided to kick off their 40s by launching Newburyport’s first brewery. Production began less than a year ago and they’re already at maximum capacity, pondering an immediate expansion on their 8,300-square-foot brick-and-mortar brewery. Newburyport’s secret weapon is head brewer, Mike Robinson, who they found working at a bank in Nottingham, N.H. A Sam Adams Longshot winner and a 19-time medalist at the Masters Championship of Amateur Brewing, Robinson brought with him more than 200 recipes, including Newburyport’s Plum Island Belgian White, a perfect warm-weather quencher. Webb and Fischer are hustling to keep up with demand, but it’s not slowing plans for a draft-only autumn seasonal and some new additions to their all aluminum lineup, which they to expect to release in early 2014. Besides the Plum Island White, try their Green Head, a heady, pleasantly bitter India Pale Ale.

Tree House Brewing Tree House Brewing is a vertitable Eden in tiny Brimfield, with views of the Pioneer Valley mountainside, a koi pond perfect for picnicking, and a fire pit where visitors lounge with growlers of Nate Lanier’s fantastic beers. “We work hard to make our little brewery a beautiful space to kill a few hours,’’ says Lanier. “It’s a peaceful, invigorating space.’’ Inspired by the highly sought after Hill Farmstead beers in Vermont, but tired of the lengthy commute, Lanier says he tried his own hand at brewing on a small kit bought for him by his girlfriend. Tree House still ferments from the confines of their limited basement space, making two of the best IPAs anywhere in the Northeast, Sap, brewed exclusively with Chinook hops and Julius, a sticky hop bomb with notes of grapefruit and mango. Now, in less than two years, Lanier has made Brimfield another Greensboro and beer fans the world over are going out of their way to sample Tree House’s rotating cast of delicacies. Besides the different styles of IPAs, Lanier also makes a decadent milk stout, That’s What She Said, and an exciting ESB, the Old Man Special Bitter.

Maine Beer Company In the brazen, madcap marketing that often takes place among craft brewers, the stark white labels of Maine Beer Co. stand out by default. But with beers like Lunch, an unfiltered, aggressively hopped IPA and Zoe, currently ranked as the best amber in the United States by Ratebeer.com, it’s obvious that what’s in the bottle is far from subdued. Launched by brothers David and Daniel Kleban in 2011 in Freeport, Maine Beer Company has rocketed into connoisseur status with its small-batch creations that are unabashedly made in the American vein. Besides advocating for better craft products from the artisanal market, they’re also pushing for the industry to embrace better environmental practices, using wind energy when possible and donating 1 percent of all their sales to organizations, such as For the Planet and Allied Whale.

Brewmaster Jack Tyler Guilmette of Brewmaster Jack describes himself as “owner, delivery guy, brewer, and janitor.’’ Brewmaster Jack is a true microbrewery in every sense, with one employee producing only 400 barrels a year out of Paper City Brewing in Holyoke. Started in 2012, Guilmete makes four year-round selections, including a delicious rye porter called Total Eclipes and a pale lager, Stray Dog Lager, made in the Germanic Helles tradition. Each of Brewmaster Jack’s everyday brews are impressive, but Guilmette is beginning to delve into far more exciting and adventurous territory. His newest beer, James, is a hoppy blonde ale made with an experimental hop variety, HBC342, that has alluring watermelon rind characteristics. “James’’ is the first in the line of small-production single releases that will trickle into the market once a month. Next up, says Guilmette, is a French saison called Soleil, and then afterward a single hop series using other unknown varieties, like HBC342, produced by the Hop Breeding Co. Get your hands on some Brewmaster Jack now, because this recondite brewery is bound to develop into a cult favorite sought by beer nerds everywhere.

Slumbrew Jeff Leiter and Caitlin Jewell are a husband and wife team of brewers who truly embrace the culinary. Blending in additions of Taza chocolate cocoa nibs (Porter Square Porter), blood orange juice (Happy Sol), local honey, and rare grains like toasted buckwheat (Attics and Eaves), there isn’t an ingredient or hop cone they aren’t willing to ferment. Leiter and Jewell have been operating out of the Mercury Brewing Co. in Ipswich since they began Slumbrew in 2011, but they’re close to settling into their own facility in Somerville complete with a tap room. A new addition to the Slumbrew family is now being released and is a must-find this summer, Sittin on Hop of the World, a white IPA brewed with wheat malts and fresh peach puree.