"WE’RE NOT big drinkers," assures Helena Wygal, the friendly faced co-proprietor of Somerville’s Arbor House Bed and Breakfast, as her husband Joe pours me a brown ale.

"Well," he corrects her as he tilts the glass just so, "I drink socially. Good beer."

Judging from the jillions of crisply colorful coasters, beer mirrors, and public-house posters that spangle the walls around him, you might suspect he’s understating the case. Joe is sitting in his own lovingly constructed and abundantly adorned English-style pub, a sanctum sanctorum erected in the name of good beer and everything good about it. Chock-a-block with bric-a-brac, it’s a minor marvel to behold.

Tucked away from the shabby storefronts of Medford street, the Arbor House back yard is a verdant oasis, complete with tinkling wind chimes, a pellucid pool, and a burbling fountain. It’s also the front yard of Joe’s warmly inviting "non-commercial, non-public free house." (Joe has emblazoned the phrase — in Old English font, natch; "free house" is what they call ’em in England — on his customized coasters.)

In addition to a gorgeous mahogany bar, three short and sturdy tables, a generous number of plush stools, and a lofty Tudor ceiling (charmingly approximated with spackle and styrofoam paneling), the Arbor Ale House boasts three working taps and three gleaming "beer engines," whose hydraulics pump out the non-carbonated, cask-conditioned "real ale" of which Joe is particularly fond. Arrayed in military formation before a stately mirror is a well-appointed selection of top-shelf Scotch.

"Three years ago, I decided that I wanted a real English-style pub," says Joe, sleepy-eyed and hirsute, in a rumbling, laconic drawl. He’d already refashioned his musty basement into an "international pub room," a working bar even more crammed with drinking paraphernalia (predominantly German- and Czech-themed). With its big-screen TV and kitchenette, it’s an ideal common room for B&B guests. But Joe wanted a place of his own. So, with a little help from his friends, he transformed his dilapidated garage into a regal rumpus room, all gussied up in brass and deep red. He figures it ran him about $5000 ("That’s everything, including the price of nails"). As he sees it, that’s money well spent: "This makes a good excuse to have parties."

But Joe is explicit that Arbor House guests shouldn’t presume that access to this swell drinkery is part of the deal. "Of course, I don’t have a license," he says. "And in no way do I want people to think I’ll give them beer. It gets to be pretty expensive if people aren’t paying for it. This is just a hobby, a very informal thing. We don’t push it with regular guests. But if I get to know people, especially if they’re beer people ... it’s understood that it’s for friends."

By "beer people," Joe means the swarms of bearded, bulbous-bellied beer-and-ale aficionados who descend on greater Boston each year for events like the New England Real Ale Festival and the Boston Beer Summit. Their word of mouth has been a significant source of Arbor House’s clientele. And when brewers or enthusiasts crash at the B&B, they’re often likely to bring along a cask or a case or a quarter-keg of their wares for some nightcap tippling.

"There are some really nice people in the beer world," Helena says, smiling. "Very generous. We always enjoy the beer people."

Joe’s love and respect for beer culture and the pub as a social institution are deeply ingrained. "Every time we travel, we always go to the pubs," he says. "To me, the pub is a community center. I’m more into the cultural aspect, actually, than the drinking."

But, he gladly admits, "they do go hand-in-hand!"

And Joe and Helena have had some grand times mixing culture and drinking in their private public house. "It’s like traveling without having to get out of the house," says Joe. "We had an Irish wedding party stay here. They brought their own priest over from Limerick and everything. Ah, the good father could drink." He sighs admiringly. "I heard him stumbling up the stairs later that night."

But for Joe, Arbor Ale House reached its apotheosis when a beat-up pick-up truck, containing the portly presence of eminent British beer writer Michael Jackson, rolled into his driveway. "He is the god!" Joe beams, still relishing the moment. "Beer nerds consider him the messiah. He was in Somerville giving a talk at some beer thing at Redbones. He came back here pretty smashed, had some Scotch, and told anecdotes."

"It was quite late," Helena adds. "We had a whole group of people waiting up for him. They all eventually went to bed except Joe."

"I couldn’t miss that!" he protests. "It was like George Washington slept here." (As he says this, a leftward glance reveals a framed portrait of Jackson himself hung with care above the room’s mock wood stove.)

That’s the point of the Wygals’ back-yard pub. It’s a place to drink well-crafted beer, make friends, and maybe even play host to someone famous. A place for the kind of parties where, as Joe proudly points out, by venturing between the former garage and the basement’s hatch door, one can "have a pub crawl without leaving the yard."

But, as its name implies, this non-commercial, non-public free house isn’t open to any Joe Six-pack off the street. Make reservations at the B&B if you want. Make friends with Joe and Helena (they’re great people; it’s easy enough to do). Prove that you’re not a loutish drunk. Impress Joe as someone who drinks for the flavor and the camaraderie, who sees mild inebriation as no more than a happy aftereffect. Demonstrate your comprehension of the difference between a barley wine and a lambic. Show you know who Ray McNeill is. (I didn’t, but now I do; I’m not gonna tell you.) Maybe then Joe will let you hang out with him in his pub. If he does, bring your own beer. The good stuff.

For more information and reservations, call (617) 623-3654 or write arborhouse@rcn.com