Who is Prime Mutton and why do New Yorkers care what he thinks about their Guinness?

There was an excitable energy at the Long Hall Pub in Midtown on Thursday night.

The crowd — mostly men in their 20s and 30s — milled about, exchanging side glances and all drinking the same black beverage: a Guinness stout.

They were there to see the man known around the world as Prime Mutton.

Jason Hackett, who goes by Prime Mutton online, is a British social media influencer who reviews food and drink from across the world. He is most famous for his reviews of local Guinness.

The Irish beer's flavor varies based on a number of factors, including its freshness, how it’s stored and its serving temperature (it should be chilled, but not freezing cold). Even the pouring technique can affect its taste — the Guinness should be poured into its special glass at a 45 degree angle about three quarters of the way full, allowed to rest for a minute or two, before being topped off with a second pour that gives it its signature creamy head of foam.

Hackett posts his reviews on social media, where he has garnered more than 1.6 million views on YouTube and boasts more than 150,000 followers on Instagram.

He’s in the midst of his first American tour — which includes a four-day stop in New York City, where he’s visiting 12 bars. On Thursday night, he was due at the Long Hall Pub and Grocery at any minute.

Suddenly, murmurs rippled throughout the space. Hackett had arrived. Within minutes, he was surrounded by fans (or "Muttonistas" as they're called) at the center of the bar, holding a fresh pint of Guinness as a hush fell over the packed crowd.

The apprehension was palpable as Hackett began filming, raised the glass to his lips, and took a healthy swig. And then, the words everyone had been waiting for: “A creamer,” he said, triumphantly.

This Guinness was indeed, “a creamer.” Not quite an ‘absolute creamer’ — the highest accolade in the Muttonverse — but still something a bar should be proud of.

The crowd went wild — cheering, clapping, chanting his signature catchphrase over and over again. The party was on.

But what is it about Prime Mutton that has his fans turning out in droves?

For starters, he’s focused on a product, Guinness, which is experiencing a bit of a boom. Though it’s more than 250 years old, it was the fastest-growing beer in 2023, according to Nielsen data cited in the New York Times.

Guinness' mild flavor and relatively low alcoholic content has made it a popular option. Its popularity has been further boosted by a viral trend, in which bar patrons try to “split The ‘G’" by taking a gulp or two to land the beer line precisely in the center of the letter ‘G’ on the pint glass’s Guinness logo.

Hackett, who also plays and teaches bridge professionally, has built a fanbase in large part by taking his job as a critic very seriously. He thoughtfully articulates the beer’s taste profile, mixing in his trademark expressions like “The proof is in the pudding” and “That’s right on the money!”

Hackett is based in Manchester, England, and part of the reason he started reviewing the stout as the world emerged from the pandemic-era shutdowns was to call attention to the particularly tasty pours he came across, which he said aren’t as easy to find as one might think.

“It should have a very, very slight hint of chocolate, a slight hint of coffee,” he said in a recent phone interview. “Guinness is very mild. … And if the bitterness is overwhelming, then that’s the problem.”

When Hackett started noticing others taking to social media a few years ago to review his favorite beer, he wasn’t impressed, so he decided to do it himself in 2023.

"A lot of what they’re talking about is absolute garbage," Hackett said of these reviewers. "These Guinness reviewers, if they’ve got a slim, toned figure — where the hell is [the beer] going? The answer is, 'Not in their mouth.'"

Hackett's Norm Peterson-esque, everyman persona is certainly part of his appeal. He’s a generously portioned, middle-aged Brit sporting a Northern English accent, a scruffy mustache, and a pork pie hat.

“It feels like an uncle. He seems like a sweet guy,” said Jeff O’Neill, who drove over two hours from Saugerties, New York to meet Hackett in the flesh.

“There’s no cynicism. … He’s just a guy who loves Guinness,” added O’Neill's friend Adam Tarchoun.

It’s been a meteoric rise for Hackett, who said his fans often spot him in the streets. For the most part, it’s been fun.

“I like meeting people,” Hackett said. “My followers tend to be very nice.”

And it’s hard to argue with him, as the bar was full of an infectious, happy-go-lucky energy. It was even silly at times. People clamored around Hackett, taking photos, asking for autographs, and just chatting with the man whose avuncular aura makes him feel like family, even when he’s on the other side of the Atlantic.

Around midnight, Hackett retired to a corner of the bar to eat some dinner. Breaks are essential, especially with another ten bars to visit over the weekend across the city.

His trip to the Big Apple was just getting started.