Eva Hernandez, 6, creates a centerpiece that contains canned food. The Edlavitch Jewish Community Center has been hosting the “Everything but the Turkey” event since 1996 to help feed those in need at the holidays. (Katherine Frey/The Washington Post)

David Melamed doesn't know where the inspiration came from to fold the top of his brown paper bag in on itself, giving his paper-bag turkey centerpiece a look unlike any of the dozens surrounding it.

"I don't know," the 8-year-old said modestly, a tuft of blue feather clinging to his shirt. "I just thought of it."

Well, David made a cool thing while doing a nice thing. He was one of more than 100 people — mostly children — crammed into the basement of the District's Edlavitch Jewish Community Center on Sunday to kick off Thanksgiving with a bit of back-giving.

"This is about taking some time from baseball and soccer and screen time to give back," said Sam Melamed, David's dad.

He and his wife had brought four children to make centerpieces — each containing a can of donated food — that would be distributed to homeless shelters.

"These guys need to be exposed to giveback opportunities," said Jay Sternberg, who was helping his two sons scoop dried onions, garlic and cilantro for rice-and-bean meal kits at one of the other tables. The kits were for families at LaSalle-Backus Education Campus in Northeast Washington, where more than two-thirds of students are at risk of hunger.

"We want them to learn to give back for others and to do it with a smile," said Jorge Hernandez as he counted the Baggies of snack mix — Cheerios, raisins, chocolate chips, pretzels — that his two daughters were building, part of the 560 that would make it to after-school programs across the region in coming days.

Yams are diced for use in Thanksgiving meals by volunteers at the Edlavitch Jewish Community Center in Northwest Washington. (Katherine Frey/The Washington Post)

All the youthful cutting and scooping was the start of the annual "Everything but the Turkey" campaign, a 21-year Thanksgiving tradition at the JCC. Nearly 900 volunteers will come and play sous chef in a massive holiday meal deployment as families, young professionals and co-workers chop, measure and mix the makings of more than 13,000 side dishes. The stacks of ready-to-bake yams, green beans, stuffing, coleslaw and bean salad will be collected by D.C. Central Kitchen, which will cook it, add the turkeys and serve more than 5,000 Thanksgiving meals at shelters across the city.

"This is a huge push for us," said Amy Bachman, D.C. Central Kitchen's director of procurement. "We want to send out more than the normal meat, salad and starch. We want to serve a feast."

Each November, the historic facility on 16th Street temporarily converts itself into a storage pantry and prep kitchen. More than 10,000 ounces of canned beans and corn fill one closet, along with 24 pounds of salt, 60 pounds of margarine and 20,000 ounces of raisins, chocolate chips and pretzels.

Upstairs in the community hall, volunteers prepared for an afternoon session geared to young professionals. As they set up 14 tables — seven green bean stations, seven yam — a volunteer wrangled a dolly stacked with some of the 21 crates of fresh produce they will go through. The event — part philanthropy, part meetup — is capped at just over 100 and has been sold out for weeks. There is a waiting list.

From left, Hilary Bernstein, Alan Randall, Molly Fisch-Friedman, Ali Lapping and Greer Rosenbaum prepare green beans. (Katherine Frey/The Washington Post)

"More than eight people at a table becomes hazardous," said Sonya Weisburd, cringing at the idea of too many millennials wielding knives in a small place. One year, someone needed stitches.

The Monday and Tuesday night sessions, heavy on stuffing and slaw, will draw almost 700 volunteers between them. Some families and sponsoring companies have been regulars for years, signing up months in advance to guarantee they get a table. Many of those have gone on to volunteer for other social causes, Weisburd said, within the JCC and beyond.

For her, the Thanksgiving campaign spins off three good things: food, awareness and people willing to help.

"It's not just the meals we're producing; it's exposing people to volunteerism," she said. "One of four children in this city are food insecure, and that's not right. We're trying to make people aware of that."

Downstairs, dozens of children, ranging in age from 2-year-olds to teens, were getting that lesson. At 6, Eva Hernandez understood who would be eating the snack mix she was making: "Kids who don't have money for food."

"I'm a kid and I like pretzels," her sister Thalia, 3, chimed in.

"But these are for kids that don't have as much as we do," said her father, Jorge.

"This is great because so many events don't want kids to be involved in meal prep," said Stacie Kaltman, holding open a Baggie at the rice-and-beans station as her son, Josh Sternberg, 7, poured a scoop of onion flakes into it. And beside it. And on her hand.

David Melamed, 8, tries to find the centerpiece he made. (Katherine Frey/The Washington Post)

Ryan Sternberg, 5, coming from dropping another complete meal kit in the bin, gave his dad a high-five coming back, their plastic gloves making a funny smack. Everyone was wearing hairnets.

Liam Brinly, 6, went table to table in a quest for a plastic spoon for a turkey centerpiece idea he had. No luck, so he headed back to his own table where his siblings Max, 6, and Hazel, 6, (yes, they're triplets) were finishing their own turkey centerpieces.

Max held up a can of pumpkin and explained: "First you put the can in the bag, and then you decorate it."

Their parents have been bringing them for several years. They want the fun of making turkeys to turn into the joy of helping others.

"It's important for us to give them a sense of giving back, because we have a lot and others don't," said their mom, Hallie Shuffler, 44.

And at one end of the basement, someone stood and began to sing a song that everyone in the room seemed to know: "Clean up, clean up, everybody everywhere; clean up, clean up, everybody do your share."