Long-time Guinness ambassador Ryan Wagner estimates that 90 percent of American bartenders know that if a customer orders a pint of Guinness Draught Stout, there’s something different they have to do.

“They don’t know exactly what, but they know they’re supposed to do something,” says the Chicago-based Wagner, head of marketing and brand partnerships for Guinness Open Gate Brewery, who’s drunk over a thousand pints of the black stuff by now.

Maybe half know to commence with the famous two-part pour: Tilt a 20-ounce tulip glass to 45 degrees beneath the tap and let the (42.8-degree) beer cascade down the side, aiming for the gold harp, until it’s three-quarters full. Allow it to settle for 86 seconds then top it off, yielding the perfect pint of dry Irish stout in, oh, I don’t know, 119.5 seconds?

Get the latest in beer, wine, and cocktail culture sent straight to your inbox.

As for the rest, “the vast array of things that happen is really remarkable,” Wagner says. Depending on what they’ve heard, they might know to tilt the glass 45 degrees, or perhaps they’ll open the tap halfway, suppressing the surge of nitrogenated liquid that creates that telltale creamy head. Maybe they’ll pour the beer in two or three or even four parts, leaving the remaining third or two-thirds or three-quarters of the beer to settle for varying stretches of time. Or they’ll fill it in one rushing go till its foamy head resembles a root beer float, thudding it on the bar to settle the bubbles like it’s a sheet tray of macaron batter. For right or so often wrong, such is the power wielded by this 265-year-old, Dublin-born beer.

But what is right at this point? Over the past decade, the chatter disparaging Guinness’s two-part pour as nothing more than a clever marketing ploy has gotten steadily louder. Guinness was the first beer to be served on nitrogen, meaning it’s pressurized in kegs with a mix of 75 percent nitrogen and 25 percent carbon dioxide. But nowadays beers ranging from stout to IPA — and even cold brew coffee — are available on nitro; bars even deploy special faucets on certain lines to facilitate correct flow, leaving the settling claim on shaky ground at best. Yet such developments are proving slow to topple a brand-crafted ritual that’s not just beloved, but proudly claimed in some form or another by so many.

“If I pour a pint of Guinness Draught stout in one part instead of two, is it going to change the way it tastes, the way it smells, the way it looks? Not if I know what I’m doing,” Wagner says. “But the connection we have to our brand, history, and heritage that comes from the two-part pour is worth more than I could possibly say.”

The Great Con?

Until the 1950s, Guinness draught was stored in two separate wooden casks, one under high pressure and the other under low, so it had to be poured carefully to yield the picture-perfect pint: a gorgeous, ruby-tinted black beer with a dense, creamy head hovering just above the rim in a quivering dome.

Guinness brewer (and mathematician) Michael Ash knew nitrogen in beer had smaller, more delicate bubbles that couldn’t break the surface tension of beer like CO2 does; they’d remain suspended, replicating the high-pressure “surge” that needed time to settle. He developed the “Easy Pour” nitrogenated dispense system, enabling single metal kegs to overtake the old wooden casks by 1959.

Suddenly, the brand had a decision to make. “Do you tell generations of bartenders there’s a new way to pour our beer?” Wagner says. “Or do you continue to have them do what made us unique?”

Guinness leaned into the two-part pour, developing a training protocol, step-by-step guide, and special handles. The brewery unleashed a series of groundbreaking ad campaigns touting the message that good things come to those who wait, helped by a flurry of capital when it was purchased by Diageo in 1997. Plenty will indeed argue that allowing the beer time to settle makes for a denser, creamier beer; Wagner has a pile of foamy evidence to prove it. But why does the 119.5-second lore persist?

The pour is one of the least important elements of a good pint of Guinness Draught Stout. Most of what can go wrong happens before the liquid issues forth from the tap; as Wagner likes to say, “a 5,000-mile journey can be ruined in the last inch and a half.”

A few nights ago, smug in my newfound illumination, I popped by my neighborhood Irish pub and ordered a pint of Guinness. The moment the bartender took up that tulip glass, however, I breathed a subconscious sigh of relief as he began the two-part pour. The dedication to this ritual comforts me, like carrying on some oral history that’s been passed down, however dubious.

Ian Ryan, the London-based creator of the @shitlondonguinness Instagram account, can relate to this feeling as someone who got famous simply for documenting shitty pours of Guinness Draught Stout in bars. The Cork, Ireland, native rarely drank Guinness Draught before he moved to London in his earlyish 20 and started seeking out Irish pubs and the “old man’s drink” for a sentimental taste of home. It didn’t take many dodgy pints for him to start sharing the multitude of sins he spotted — along with each offending bar’s name: headless pints, ice cream floats, and heads bedazzled with dreaded foam art; Guinness Draught served in Foster’s mugs, red wine glasses, and Chinese takeout containers. (He tracks the good ones, too, by the way, on @beautifulpints.)

Ryan figured it would resonate, but not to the tune of more than 250,000 followers, a line of merch, and a book deal. (“A Beautiful Pint: One Man’s Search for the Perfect Pint of Guinness” was released in the U.S. on Feb. 20.)

“It’s such an odd one, because obviously people care about and go into intricacies about lager — I’m sure people do — but there’s something about Guinness,” he says. “People think, ‘This is what it should be’ kind of thing.”

Emotional Ownership

Ryan endorses the two-part pour, mainly as an insurance policy to secure that satisfying, creamy dome. But if he’s being honest, the pour is one of the least important elements of a good pint of Guinness Draught Stout. Most of what can go wrong happens before the liquid issues forth from the tap; as Wagner likes to say, “a 5,000-mile journey can be ruined in the last inch and a half.”

Whenever someone (inevitably) asks Ryan to divulge where one might find the closest thing to a perfect pint of Guinness Draught Stout, he always mentions the iconic Dublin pub John Kavanaugh, a.k.a. “The Gravediggers.”

Is the beer being stored at the right temperature? Are the draft lines and steel restrictor plates clean? Is the glass washed and well dried? Are the kegs fresh?

It’s human nature to assume some level of ownership over the things we love — to want to leave our own foam-art stamp, if you will. Indoctrination into the cult of Guinness and how it’s poured allows this. Wagner fondly recalls one bartender in Charleston, S.C., who poured Guinness Draught Stout in three parts because that’s how his Irish-born grandfather taught him.

“He launches into this beautiful story of how the first sip of beer he’d ever had was sitting on his grandfather’s knee in the bar in the little Irish town where he was from, where he’d learned to pour it this way,” Wagner says, “and that every time this bartender poured one it made him feel closer to his grandfather. Then he looks at me and says, ‘Am I doing it wrong?’”

Ryan’s heard of pubs that swear by the three-part pour to yield the finest possible pint; others say the key is to thud the beer gently on the bar after topping it up. “There are all these little tricks people swear by,” he says. “It’s one of those things with no super-definitive answer. And Guinness just wants us to keep talking about it.”

Whenever someone (inevitably) asks Ryan to divulge where one might find the closest thing to a perfect pint of Guinness Draught Stout, he always mentions the iconic Dublin pub John Kavanaugh, a.k.a. “The Gravediggers.” Established in 1833, this family-owned bar sits at the eastern edge of Glasnevin Cemetery in the residential Prospect Square neighborhood. It’s dark, loud, and narrow, all weathered wood and bubbling floors. TVs and music aren’t allowed, apparently even if you’re The Chieftains, The Dubliners, and U2 starting up a spontaneous live set to honor a late bandmate.

Every pint of Guinness Draught Stout here is, naturally, poured in two parts. The wait for your beer is baked into the place itself, like the streaky patina on the original countertops and soothing din of chatter all around. Finally the beer arrives, harp out and pretty as a picture, the liquid embodiment of a bonafide Irish pub. At this moment, a small measure of this bar becomes yours, too, as the place where you had “Guinness that tastes just like it should.”