Reports of the Aussie burger's demise have been greatly exaggerated. With the influx of American-style burger chains over the years, you could be forgiven for wondering if the suburban classic Australian burger was on the way out.

This week popular American burger joint Five Guys announced its entry to the Australian market, following the well-worn path of McDonald's, Burger King and KFC in decades past. More recently Carl's Jr has grown its Australian footprint to 20-odd stores nationwide while another favourite, In-N-Out Burger, continues to tease consumers with occasional temporary pop-up stores.

But the owners of a south Sydney burger institution say demand for the Aussie variety remains sky-high. Paul's Famous Hamburgers in Sylvania has been serving burgers using the same recipe since 1957. The venue is a pillar of stability in a constantly changing city.

The business is jointly owned by the Sinesiou family who took over from the original owners in 1998. Chris Sinesiou, one of four brothers who share a stake in the restaurant alongside their parents, defines the Aussie burger as being simple and fresh.

"The American burger concept is very much a cheeseburger in its essence. It's that greasy cheesy burger that is appealing to that market. Whereas we offer a dynamic where it's … egg, bacon, cheese, pineapple, fresh or cooked onions. It's a bit more of an experience, something that's unique."

Mr Sinesiou is adamant the creeping advance of the US chains does not threaten his offering.

"Not at all. The numbers speak for themselves," Mr Sinesiou said. "A lot have come and a lot have gone. If they were to be a risk we would have declined and they would have kept flourishing. I'm sure there are a couple that are doing well but I think they serve their market and we serve ours."

Jake Smyth, owner of Mary's in Newtown which serves American-style burgers, agrees that the Aussie burger isn't going out of fashion anytime soon.

"If you were to stack up burger by burger and style by style there'd be more Australian burgers being consumed [nationwide]," he said.

"I don't think Five Guys will touch the sides of the Australian appetite for the classic Australian burger."

Paul's is widely regarded as serving some of the best burgers in Sydney, and it's the quintessential suburban Aussie business. Families, groups of friends and tradies flock in during Thursday's lunchtime rush to sample the works burger and signature pineapple juice.

Nick Sinesiou – the family patriarch – sits outside greeting customers, most of whom he says he knows. "If you are good to them, they are good to you," he said.

Paul's even remains steadfastly cash-only, eschewing the tap-and-go culture that much of Australia has embraced.

Mr Smyth said his Mary's establishment and places like Paul's have something big US burger chains never will.

"What we try to do is create a community. That community heart will always beat the f---ing heart off a franchise … they can't replicate what we do."

Mr Smyth said the "explosion" of the burger craze could be traced to the advent of social media.

"After Instagram hit that's when they started to expand [and] became this cult-like thing. People devote their lives to posting so-called burger porn. "

But at its core the burger obsession is "rooted in something real which is nostalgia" for a generation who grew up during the wave of American fast food entrants.

"This is what street food was to an entire generation of kids in Western culture," he said.

Mr Sinesiou thinks the popularity of the burger can be simply attributed to the fact it is a "complete meal".

"It's got the meat, the salad, the bread, the sauces," Chris Sinesiou said. "It's just a very wholesome all-round meal that's very sustaining. You get your side of chips, your milkshake and you're done. It's very fulfilling, it ticks all the boxes. It's an all-round sensation for the tastebuds."