Data shows that the number of delicatessens in two popular New York City neighborhoods has increased substantially this century, despite questions about whether the traditional deli is dying.

The city is known as a great place for restaurants, and it is also known as the place to go to a deli. There is of course the famous Katz's Delicatessen, but there are two neighborhoods that may be most associated with deli food: the Upper East Side and Upper West Side.

For more than 100 years, people have sliced smoked fish at Barney Greengrass.

“Trying to keep that tradition going,” said Gary Greengrass, owner and grandson of the man who started it all.

Barney Greengrass started as an appetizing store, but is now better known as a deli.

“We devoted our lives to the business. It’s part of our business," Gary Greengrass said. "Like when my son says 'Dad, when are you coming home?' I go, 'I am home.'”

Since 1929, home has been the Upper West Side on Amsterdam Avenue between West 86th and West 87th streets. Greengrass does what he can to keep the old-school charm, even when it comes to the wallpaper.

“It’s been here more than 60 years. I had a few decorative painters here for five days to fix it up and make it look like it’s always been there," Greengrass said. "And that’s the look I want. Probably cost me five times what it would cost to put on new wallpaper.”

But even though things may not change inside, the headlines over the years serve up a different idea of the future of the deli.

They have been around since the 1800s when Europeans migrated to the United States. But could the traditional deli be dying?

“If I predicted the future, I’d be picking stocks instead of lox,” Greengrass said.

He said he still sees the demand and has a loyal customer base that runs generations deep.

On the other side of Central Park, the photos on PJ Bernstein Deli’s walls shows just how old it is.

“Back in the '70s and '80s, this was the most popping neighborhood in New York,” said Eugene Slobodski, who owns the deli and took it over from his grandfather.

So what does he think about the deli’s future?

“I think for the future, I hope all the delis that are around keep their roots," Slobodski said.

The number of listed delis in both neighborhoods has actually increased over the years.

The number of delis just about doubled from 1973 to 2000 on the Upper West Side and Upper East Side, according to copies of the Yellow Pages that NY1 examined at the New York Public Library.

And when taking that data from 2000 and comparing it to an online version of the 2023 Yellow Pages, the number of Upper East Side delis decreased by about 12%, while Upper West Side delis increased by nearly 50%.

“I would never say that the deli is dying because it doesn’t feel like it,” said Ben Nadler, who wrote a book called “The Jewish Deli: An Illustrated Guide to the Chosen Food” that examines the past, present and future of the industry.

Nadler said that rather than disappearing, delis are simply changing. They have become a food genre, available just about everywhere and for just about everyone, from the corner store to the grocery store.

“The invention of the contemporary Jewish deli,” Nadler said.

And what he means is that people can even find places that bill themselves as vegan delis.

This is one way to try to attract a younger clientele. Slobodski said this is his goal for PJ Bernstein Deli, as well. He has been more focused on online sales and takeout, even trying late-night drinks.

“Like nothing was really clicking," Slobodski said.

So he is sticking with what he knows. The same goes for Barney Greengrass on the Upper West Side.

They are serving up deli staples with a healthy dose of tradition.