Exclusive | 20-hour days, thousands of sandwiches made the blood, sweat and tears it takes to put on the century-old San Gennaro Feast

People wait all year for the Feast of San Gennaro.Vendors pay thousands of dollars for the chance to be there.And then, almost overnight, Little Italy comes alive.

Food stands spring up along 11 blocks, the smell of sausage and peppers fills the air, music spills into the streets and an estimated million people descend on the neighborhood.That transformation can look effortless.It isn’t. Months before the first cannoli is sold, organizers and vendors are already spending money, securing permits, arranging trucks and running power — building the beloved festival, which celebrates its 100th anniversary this year, one piece at a time.“We start planning in November, and I can’t tell you how many meetings we’ve had with various agencies,” John Fratta, vice president of the Figli di San Gennaro organizers, told The Post. The festival, which runs through Sunday, must comply with a web of regulations governing everything from gas and water to public safety.“It’s absolutely nonstop,” said Fratta, whose great-grandfather, Luigi Vitale, was the first president of the organizing committee.A large part of Fratta’s job is corralling and placing vendors, with applications pouring in for the festival’s milestone year.

This year, 220 vendors make up the festival, including 75 cooking up everything from classic Italian dishes to sweet treats.The rest hawk everything from crucifixes to T-shirts.“This year we have a lot of new vendors, but many of them have been with us for decades,” said Fratta, who grants approvals as long as there’s space.The aforementioned organizing committee institutes a seniority system, with some of the most veteran vendors getting prime spots on Mulberry Street near its intersection with Grand.The farther away from that corner, the less desirable the spot, or so the thinking goes.The committee also spaces out similar vendors so they don’t cannibalize one another’s business.

Vendors guard their turf, after all, especially wh...