The Sullivans speak of their hot dogs with a certain reverence.
Behold the noble “snapdog,’’ as Dan Sullivan, owner emeritus of Sullivan’s Castle Island, calls the family favorite of the renowned stand’s offerings. Many other hot dogs are served with the casing off, but ever since 1951, when Dan’s father opened the stand, they wanted casings still on.
That way, the juice stays in, said current owner Brendan Sullivan, Dan’s son, “and there’s that pop when you bite in.’’
On Saturday , the Sullivan clan opened their South Boston institution for its 74th season, slinging burgers, dogs, and crinkle-cut fries to a family-heavy crowd. Despite rapid changes in Southie over the past few decades, Sully’s clientele, like its hot dogs, has changed little. It’s the people who grew up a generation or two ago in the now-pricey neighborhood who find themselves making a pilgrimage back from the suburbs, year after year, to share a taste of their childhood with their children and grandchildren.
“I grew up in Southie, and I came here when I was their age,’’ said Dan Moore, now of Holbrook, gesturing to his 4-year-old twins, Caitlin and Drew. The kids were sitting at a picnic table, each holding part of a hot dog as they contentedly chewed on the rest of it.
“They just love it,’’ he said.
This year, opening day arrived just a few days after some good news: The prestigious James Beard Foundation, an arbiter of honors in the food world, crowned the humble hot dog stand with its America’s Classics Award. The category recognizes locally owned restaurants with “timeless appeal that serve quality food and are beloved by their communities.’’
When Brendan Sullivan, 52, first received an email about it, he assumed it was a scam.
“You’re like, is this real? It can’t be real,’’ he said Saturday. But a phone call followed, and, ultimately, Sullivan was convinced.
“It’s like winning the Oscars,’’ he said, beaming as his employees took food orders a few feet behind him.
Four generations of Sullivans have worked at “Sully’s,’’ which has recently expanded with outposts in Hanover and Hub Hall, a food emporium near TD Garden. Brendan Sullivan, standing next to his dad, Dan, and 20-year-old son, Thomas, who’s a manager, said it’s the only job he’s ever had.
The crowd at Castle Island on Saturday mirrored that family tradition. On the benches outside, grandparents chowed down on hot dogs next to their adult children and young grandkids.
Through conversations with the people there, you can hear a throughline of modern Boston history. The older folks lived in Southie many years ago, and happily recalled eating dogs and burgers that Dan Sullivan or Dan’s father, Dan Sr., served them up. But then, as many did in the face of the tumult of the 1970’s busing crisis and the skyrocketing prices of property in Southie more recently, they left. Many of the people for whom Sully’s opening day is an annual rite of spring now come here from the north or south shores.
Michael Healey, 70, grew up in Southie before moving to Weymouth. That’s where he, his sons Aidan, 26, and Keenan, 28, and their colossal Bernese mountain dogs, Bentley and Atlas, made the trek up from on Saturday morning. They bought an assortment of burgers and dogs, and bickered good-naturedly about who’d eaten whose burger.
Aidan said he’s always happy to make the trip.
“Eat a hot dog, take a lap around Castle Island — it’s not too bad at all,” he said.
“I’ve been coming here for 60 years,’’ Michael Healey said. “The hot dogs and burgers are the exactly the same.’’
And a couple of bites confirm: The hot dog still has that toothsome pop.
Nearby, a 14-month-old named Jeannie sat in a carrier with a smile on her face as she prepared to split a burger with her mom, Nora, 31. Nora’s mother, also named Jeannie, is from South Boston, though the family now lives in Quincy.
“If you’re from here,’’ said the elder Jeannie, “You just know this place.’’
Sean Cotter can be reached at sean.cotter@globe.com. Follow him @cotterreporter.