It must be something in the food.

At the annual Greek Festival on the banks of Bayou St. John, visitors flock to an ad hoc grocery store, pastry shop and rotisserie to fill up on delicious homemade Greek meats, fries and desserts that can’t be found in New Orleans at any other time of year.

Then, the dancing starts.

“Once people have been here and have had some food and drink, they just grab on and get in line and follow the circle dancing,” said Ginny Zissis, chairperson of the Greek Festival, referring to the two-steps-forward, one-step-back national dance. “They have no inhibitions. They become Greek for the weekend.”

The grocery has everything from classic favorites such as hummus, baklava and gyro sandwiches to more obscure delicacies: dolmas (stuffed grape leaves), goatburgers, feta fries, galaktoboureko (custard-based phyllo dessert) and saganaki (a flame-lit treat).

“Everything is homemade. My family, friends and I do everything. We try to make as much as we can, but last year, we ran out of so many things so early in the weekend,” said Billie Andersson, head of the grocery for the Greek Festival.

“And the pastries! People love them, and they go out with boxes and boxes. People come just for the pastries, and they always sell out,” Andersson said.

Takeout items and pantry goods such as honey and olive oil are also on sale.

“We also have an entire display of Greek products for sale and cooking demonstrations. We even have gastroenterologists and cardiologists, who are members of our community and will be speaking about the health benefits of the Mediterranean diet,” Andersson said.

When you have had your fill, head over to the main stage to clap along to the Hellenic dancers moving to the traditional Greek sounds of Alpha Omega!, which features the bouzouki, a plucked string instrument with a pear-shaped body and a long neck.

“Our Hellenic dancers will dance in costumes representing different parts of Greece, and they put on a beautiful show during the festival,” Zissis said. About 10 shows are planned.

The festival originated out of the local Greek Orthodox community’s need to raise money for its new cathedral 41 years ago.

As the festivities take place on the grounds again this year, the community is marking the 150th anniversary of its cathedral in New Orleans.

“Most people that are Greek are Greek Orthodox, and the faith goes with the culture and the tradition,” said Zissis.

“They see the fathers cooking the lamb, the sons and daughters dancing in the dance troupes and the moms making the pastries.

“I think they enjoy seeing that family effort of trying to keep a culture, a community, a religion going and growing.”

The public can marvel at the architectural and artistic beauty of the cathedral while learning about the Orthodox faith during the free tours being offered to festivalgoers throughout the weekend.

“Be outside, enjoy all the cultural stuff and then go into the cathedral, do the tour and hear about the religion. I think it brings them closer to what we are and how we survived,” Zissis said.

Back outside, amid the blue and white flags fluttering along the banks of Bayou St. John, is the Athenian Playground for kids of all ages, including a “Mount Olympus climbing wall,” a 400-square-foot climbing rock.

Other activities include inflatable bounce houses, face painting and kids crafts. Canoes will be available to rent for rides in Bayou St. John, lending an authentic Greek isle vibe to the scene.

An outdoor marketplace, the Agora, offers Greek jewelry, art and even clothing for Toga Sunday, when anyone dressed in a toga is admitted free.

A class in iconography will focus on the Byzantine artwork.

There’s a “Best Toga” contest Sunday evening after the 6:30 p.m. outdoor Hellenic dance presentation.

As the Holy Trinity community pulls together to bring out the Greek in all of us, New Orleanians in turn embrace their culture and traditions.

“It takes so much energy, so much time, but it is love. It brings out so much of our tradition and the things that we love to do, and it just holds everybody together,” Andersson said.

The festival is on the church grounds at 1200 Robert E. Lee, at the of corner St. Bernard Avenue. Free parking and shuttle service is available from the John F. Kennedy High School site and along the route.

Admission to the festival is $5 for adults and free for children younger than 12.