Hours before the gates open for Saturday’s Sweetlife Festival, long before pouty pop singer Lana Del Rey coos the breathless chorus of “West Coast,” the lone sound spilling out of Merriweather Post Pavilion will be the hum of cooking.

In the steel kitchen of Astro Doughnuts and Fried Chicken downtown this week, there was some music — specifically, the buoyant loafer-pop of Vampire Weekend — which seemed to rally pastry chef Elizabeth Masetti through her second consecutive 14-hour day of sifting flour, cracking eggs and making dough for the 2,000 doughnuts Astro will bring to the festival. Masetti needed the distraction. Tack on the 1,000 she will also prepare for Saturday sales at the shop, and she is on the hook for 3,000 doughnuts, three times her usual order.

By the time the sun rises Saturday, Astro’s kitchen will have fried that heart-stopping figure of pillowy pastries, some torched to taste like creme brulee, others drizzled in a strawberry glaze, still more made without sugar to be piled up later with fried chicken and bacon in a kind of regrettable county-fair version of a BLT.

“It’s all hands on deck,” said Elliot Spaisman, Astro’s co-owner, of the days leading up to Sweetlife. On Friday he scheduled four people to work the graveyard shift with Masetti, rolling dough, proofing it, frying. Saturday at 5 a.m., four more will have arrived.

This stressful, financially precarious version of a “Top Chef” challenge is playing out across Washington, as two dozen businesses crank out doughnuts, tacos, hundreds of banh mi sandwiches and thousands of oysters — all of it bound for the admirably flat bellies of the 20,000 teenagers and 20-somethings headed to Saturday’s festival.

The festival, which takes place at the outdoor Columbia, Md., venue from noon to well past dusk Saturday, pairs Del Rey with party rapper 2 Chainz, electronic act Chromeo and Los Angeles hand-clappers Fitz and the Tantrums. But Sweetlife, which began in 2010 as a Dupont Circle block party thrown by local salad chain Sweetgreen, gives food equal billing on the marquee.

Feeding the Sweetlife crowds requires vendors to ratchet up production exponentially for a customer — millennial, fickle — whose tastes can’t always be gauged. But it has the potential to be a marketing gold rush.

Two years ago, food trucks dominated the festival, but as the District’s restaurant scene has mushroomed, fewer trucks and more up-and-coming food vendors have been tapped to cook, each paying $500 to $1,200 for the honor (and the power hookup). In exchange, Sweetlife helps them prepare for what could be their biggest day in business. Laura Rankin, director of the festival, urges vendors to expect 1,000 to 1,200 customers. This year, Rankin and other organizers also helped the vendors curate their menus, streamlining their offerings to three items apiece. “We’ve learned a lot over the past two years,” Rankin said. “In the festival, a lot of vendors would have six, seven or eight things, and they wanted to replicate their restaurant experience at the festival. And that’s just not possible.”

Bettina Stern and Suzanne Simon, who opened their veggie taco stand, Chaia, only a year ago, will pat out and fill their made-to-order tortillas at the festival for the first time. On their best days under a 10-by-10 tent at farmers markets, they serve perhaps 180 people their tacos, which come stuffed with such combinations as kale and pickled onion dusted with herbs, or local asparagus and roasted potato. At Sweetlife, toting along 60 pounds of kale, 90 pounds of Red Bliss potatoes and 120 pounds of white button mushrooms, they expect they can serve 500. It will be a precious 500, many of whom will hail from the suburbs and neighborhoods where Chaia has yet to make inroads.

The vendors have done their best to prepare — they’ve staffed up, developed virtual playbooks for every possible scenario. But there is one factor they can’t control: the weather.

Concertgoers can pull on ponchos if the skies open up — as they are expected to — but yeast, the very soul of the light and airy doughnut, Spaisman says, does not play so well with rain. “Humidity is not the best for it,” he admits, a hint of worry beginning to creep into his voice. Then there are the glazes, the delicate creams. “As long as it’s not too hot, we’ll be okay.”

Rain drenched the vendors in 2012 and 2013, the first two years Erik Bruner-Yang brought a version of his perennially packed, 20-seat Taiwanese ramen shop, Toki Underground, to Sweetlife.

“We were prepping in the rain, setting up in the rain, breaking down in the rain,” recalled Bruner-Yang, whose staff was chilled to the bone for hours on end. This year, the chef has taken the lesson to heart and says his team is mentally prepared for wet weather. “But if it’s warm, that would be awesome.”

Bruner-Yang will create an Asian-style night market, setting up a string of hawker-style stands within Sweetlife. Swing one way, and you’ll find Spike Gjerde of Baltimore’s Woodberry Kitchen roasting a whole pig, or the staff of the not-yet-open Maketto folding puffy steamed dough into pork buns. Turn another, and you’ll see the steam rise off a cauldron of ramen, Bruner-Yang’s specialty.

“This is way simpler than last year,” he said. “We did like 30 items last year — we went crazy. With that many people, you just need to be clear and concise: ‘This is what I’m selling, this is how much it is, if you like it, great. If not, go to the guy on the right, he’s got something else for you.’ ”