Before Matt Horn served his first plate of smoked brisket and ribs out of an old service station at 17th and Center Streets in West Oakland on Saturday afternoon, more than 100 people were outside the building waiting to order. The scene was like a musical festival and Horn’s popup was the headlining act.

“I’ve waited two hours before for his barbecue,” said a young woman who was eating a bag of chips near the back of the line. “It’s always worth it.”

An older man ahead of her called Horn’s food “the best barbecue in America.” The sentiment was echoed by others, and some would end up waiting two hours to get to the front of the line.

It was Horn’s first popup since announcing he would be opening a brick-and-mortar version of the business in Tanya Holland’s former Brown Sugar Kitchen space in West Oakland. The restaurant, called Horn Barbecue, has a tentative opening date set for late March or early April. Over the last two years, Horn has been profiled in numerous national publications, including Food & Wine magazine, hosted exclusive dinners with barbecue legends like Adam Perry Lang, and headlined food festivals in Texas and Los Angeles.

Never has a Bay Area barbecue pop-up garnered the same level of attention in the same amount of time as Horn Barbecue, which hosted its first Oakland pop-up in 2016. The Chronicle called Horn “the future of Bay Area barbecue” in 2019 for his skill with brisket, which he serves tender and buttery, similar to what folks can find in East Texas. The brisket is also why Horn was named a Rising Star Chef by The Chronicle that same year.

Horn said the restaurant project is mired in permitting red tape but he’s content with the progress that has been made over the last few months. Hosting the pop-up was a chance to take a break from the construction and “reconnect with the people,” Horn said.

The Chronicle recently had a candid conversation with Horn about his forthcoming restaurant and what customers can expect. (The interview has been edited for clarity.)

On why there’s a giant mural of a cow on the side of the building:

“Beef is king. Some people down South say barbecue is basically just pork, and that it’s all about cooking the whole hog. But in Texas, it’s all about the beef. I just wanted to show that message to people as soon as they get here...In this kitchen, we appreciate the beef. We appreciate the cows and where the beef we eat comes from.”

On what people can expect on the restaurant menu that may differ from the pop-up:

“We’re definitely going to be doing our oxtails...We are going to be doing lamb as well. We’re also going to be doing the tri-tip. It’s easy for us to do ribs and pulled pork, so we wanted to do more than that.”

On what menu item he takes the most pride in:

“One of the challenges I’ve had to face in developing my product is getting that brisket right...It took a lot of trial and error...The Horn house was built on our brisket at this point. But earlier on, when we were doing our pop-ups, I was only doing ribs, pulled pork and chicken. There was no brisket. But now I’ve gotten the brisket to the point where it’s consistent.”

On how an American flag hanging in the dining room has deep roots in the world of barbecue:

“That flag used to hang in front of Louie Mueller Barbecue (in Texas). They call Louie Mueller Barbecue ‘The Cathedral’ since so many people have gone there and had this epiphany of what they want to do in their life, including (famous pitmaster) Billy Durney, who said he went there and that’s what made him decide to start doing barbecue.”

“Wayne Mueller (Louie Mueller Barbecue owner and pitmaster) gave it to me as a gift. I wanted to do right by it.”

On why he kept the diner-style seats of Brown Sugar Kitchen but covered them in cowhide:

“I wanted to stay in the realm of barbecue with the look but also have that old, family diner feel as well. So we thought it would be cool to have the cow hides, which are shipped in from Wyoming, on the seats. It all plays along with the story of barbecue and what it represents. Plus the look is beautiful, and that’s what we wanted to do, put something beautiful here in West Oakland.”

Horn Barbecue. Opens March or April. 2534 Mandela Parkway, Oakland.

Justin Phillips is a San Francisco Chronicle staff writer. Email: jphillips@sfchronicle.com. Twitter: @justMrPhillips