SUMADIJA, Serbia -- Jovana Erovic is a woman in demand. Muscular, with close-cropped blond hair and cloudy blue eyes, she can hardly get a word out without a passerby interrupting her to congratulate her on the success of the festival.

It is the first Saturday in September and the sun is beaming down on Erovic and the few thousand gourmands, chefs, locals, and visitors that have gathered in a field in Lunjevica, a small village nestled in the verdant hills of the central Serbian region of Sumadija, for the World Testicle Cooking Championship.

Erovic is sitting on one of a dozen small hay bales under a marquee that functions as the focal point of the festival. Facing her is a stage where a rotating cast of musicians perform everything from soul to classic Yugo-rock to indie hits. With food and drinks in hand, friends and families happily mill about as smoke rises from the campfires, where the competing teams are busy preparing their own unique culinary takes on the dish of the day: testicles.

It was Erovic's father, Ljubomir Erovic, who started the festival in 2004. From its humble beginnings, it soon became a regular fixture on the region's calendar, attracting international media attention from around the world.

The consumption of animal testicles has a rich history in Serbia, with longtime Yugoslav leader Josip Broz Tito said to be a fan. But the dish has fallen out of vogue in recent years -- and Ljubomir wanted to change that. He grew up in Lunjevica, where eating testicles was a long-standing tradition and the village was famous for its testicle stew. Along with founding and running the festival, Ljubomir also published a 2008 recipe book called Cooking With Balls.

After his death in 2019, Erovic vowed to keep the festival running, in part to honor her father's legacy. "He was a free spirit," Erovic said, visibly moved and reluctant to speak too much about her father. "He had some ideas that nobody understood and, in the past, he got in a lot of trouble [for them]."

"In the Balkans...it's very hard to find somebody to support your ideas when they're very big -- like big for the [whole] world -- and they don't understand you. Well, that is something I'm trying to fix," said Erovic, who also works providing humanitarian assistance to refugees transitioning through Serbia.

Food festivals are serious business in Serbia, with hundreds taking place every year, often dedicated to the preparation of a particular type of food. Many follow a descriptive naming convention, whereby the suffix "-jada" is added to the foodstuff being celebrated. For example, the festival of cabbage ("kupus" in Serbian) is the Kupusijada and the festival of bacon ("slanina") is the Slaninijada.

Erovic says that when her father started the festival, he wanted to call it Mudijada -- quite literally, "Balls Festival" -- but the local authorities would not allow it, viewing it as obscene. "They told my father that so long as they are alive, Mudijada will never happen," Erovic said. "These people were like horses, blinkered. They didn't have a broad outlook."

The festival, Erovic says, was founded as "a parody of all the other jadas where you have turbo-folk music and a lot of drunk people." The festival was not just a light-hearted celebration of an oft-overlooked food but perhaps also an alternative to the sometimes-reactionary atmosphere that can hang over other jadas, Erovic explains. As a compromise, Ljubomir settled on Mudrijada, substituting muda (balls) with mudra (wise): making it the Festival of the Wise.

Turbo-folk -- a fusion of folk music and pumping dance beats that is ubiquitous across the Balkans -- is conspicuously absent from the festival. As Erovic speaks, an American expatriate belts out Van Morrison's Brown Eyed Girl from the stage. "When you come here, you see there is not [just one] specific group of people.... You have professional chefs, you have kids, babies, you have the old men. You have everybody here," Erovic said. "It's a festival of love."

Radovan Subin set off from his hometown of Kikinda in northern Serbia at 5 a.m. to make the nearly 300-kilometer journey to the festival. "Almost every day, I come to one of these festivals, because I'm a master chef," Subin said. As president of the festival jury, Subin will be awarding prizes in two categories: the best testicle goulash and the most innovative dish. It is worth the journey, he says, because the testicle goulash is so special in this region of Serbia.

"They make it in a way that is very specific to this part of the country," Subin added. "The goulash is special because with one bite you can taste everything. Sugar, salt, spice -- it contains everything. It's a challenge even for me to judge it, because it's so unique," he said.

Stefan Markovic, a 30-year-old soldier enjoying growing a beard while on annual leave back in his home region, says he was 22 when he first ate testicles. "My friends and I were buying hay in a village and a neighbor asked if we would like his grandma to prepare some for us," Markovic said from behind a pair of white sunglasses. "It's not an everyday meal. I think some things should be reserved for special occasions, so they don't become boring."

Testicles, usually from bulls, goats, or sheep, have been eaten around the world for centuries and are normally roasted, fried, or simply boiled. Sometimes thought to boost male virility, they usually come from young animals being raised for meat rather than breeding and are often referred to by euphenisms for the sake of politeness: In Serbia, they call them "white kidneys" and in Canada, "prairie oysters."

What effect, if any, eating testicles has on one's health is a matter of debate. Writing two millennia ago, the Roman author and philosopher Pliny the Elder prescribed them as an epilepsy cure. Eleftherios Diamandis, a professor at the University of Toronto's Department of Laboratory Medicine and Pathology, told the Imaware health blog in 2020 that the dish "will lead to a temporary boost in your own testosterone levels." While a popular delicacy in Lunjevica, only a handful of restaurants serve "white kidneys" in the capital, Belgrade, and they are unlikely to become a mainstay of Serbian cuisine.

Back among the tents, campfires, and chefs at the Mudrijada, not everyone is agreed on the best way to cook testicles and a number of different techniques are employed.

Drawing a crowd with their Berlin-style testicle doner kebab, which they are cooking on a purpose-built, wood-fired rotisserie oven, is German engineer Julius Bretschneider, who has traveled from Dresden to compete in the innovation category with his younger brother Anton, who is a professional chef.

"The first time I came here, I was traveling in Serbia with a friend. I read about the festival and I said, 'We have to go there,'" recalled Bretschneider, a thick metal chain wrapped around his neck. "The biggest question we had was: Is it only funny for us or also for them? Of course, we got here and realized immediately...everyone is like, 'Ha-ha, balls!'"

In 2021, Bretschneider returned with Anton, and their team, the Balls Brothers, snagged second place with their testicle sausages, which Erovic still remembers to this day. Their success in Serbia has led to minor fame back home, including a television appearance cooking testicles for a German rapper and soccer player.

"It's called a 'rocket stove,'" said Bretschneider, describing his custom-built oven. "It's got a low air intake, the wood goes in from the top and burns next to the kebab, and the long chimney promotes air flow."

For other competitors, though, cooking testicles is more of an art than a science. Markovic, the soldier on leave who is captaining a team that loosely translates as Crazy Balls, says they are still learning how to cook their testicle stew. "You need to strike a balance to preserve that special character testicles bring to a meal," he added. "We're going to keep perfecting this recipe for at least another six or seven years."

Milorad Vukajlovic, who goes by the nickname Mrso, has won the Mudrijada so many times that Erovic has withdrawn him from the competition and now appointed him as an ambassador for the festival. Vukajlovic serves up a piping-hot goulash with a spicy kick that is rich and gamey. The testicles themselves have a satisfying, liverish quality. Asked what his secret is, Vukajklovic is coy: "The secret is 45 kilograms of balls," he quipped.

The key, according to Erovic, is to clean the testicles thoroughly and then either boil them or marinade them for at least 24 hours. "It's not good when you [can] feel the real taste, [because] the real taste is testosterone," she said. "For men, it's something like an aphrodisiac. But that is something you need to speak with the boys about, because I can tell you that with the girls it doesn't work."

While the attendees at Mudrijada may skew heavily male, especially in the composition of the competing teams, there is still a sizeable contingent of women at the festival. But as the day progresses, the levels of testosterone seem to be rising.

On a slope overlooking the campsite, teams of barrel-chested men duke it out over games of tug-of-war. Their faces warped with exertion, it is rarely more than seconds before one team prevails, often dragging their opponents, still clinging to the rope, along the grass.

After the prizes have been awarded and the sun is beginning to set, the celebrations become more raucous. "It's like Las Vegas. What happens in Mudrijada stays in Mudrijada," Erovic said. "And at Mudrijada, everything happens."

For Crazy Balls captain Markovic, it's not about the winning, though -- he knows that older and more experienced teams will go home with the prizes today. For him, he says, it's about more than just the food, it's a way of keeping in touch with his roots and reconnecting with all the friends he grew up with and left behind.