In spring, residents of Dongyang, in coastal Zhejiang Province, China, according to the N.Y. Times, chow down on eggs simmered in steaming pots of boys’ urine.

Sold since ancient times as “virgin boy eggs,” the local delicacy was officially listed as “intangible cultural heritage” in Dongyang in 2008. Many residents believe they energize the body, improve blood circulation and prevent heat stroke. They are also a bargain at around 25 cents an egg, urine included.

Across Dongyang, a bustling city of nearly one million people, fresh urine is collected every day from buckets placed in elementary school hallways, where boys under the age of 10 are instructed to answer nature’s call — as long as they are not sick, out of concern for, um, food safety. Some vendors even carry around empty bottles and wait in parks or public bathrooms until they find a parent who is willing to let their prepubescent son participate in the custom.

Chinese medicine practitioners are divided on the supposed benefits of ingesting urine, which modern science has shown to have no nutritional value. But the locals in Dongyang are happy to shower praise on the eggs they call “the taste of spring.”

To prepare the eggs, chefs generally stick to a time-tested recipe: First, soak the eggs in pots of urine and bring to a boil. Remove the eggs, crack the shells, then return the eggs to the pot and simmer for about a day, adding more urine as necessary, sometimes with herbs. The marinade gives the egg whites a pale golden hue, while the yolks turn green. They are also quite salty, according to Wu Bei, 39, an employee at the Zhang Yuming Chinese Medicine Clinic in Dongyang.

“They taste a bit like urine, but not too much,” she said. “It’s delicious, you should try one sometime!”