For many, spring means flowers and shedding winter underwear, but for the city of Dongyang in Shanghai’s neighboring Zhejiang Province, it also means that it's time for virgin eggs.

For those familiar with tea eggs -- hard boiled eggs soaked in a mixture of soy sauce and vinegar -- virgin eggs are similar but with one exception: the dish is prepared with the urine from young boys.

The delicacy costs RMB 1.5 compared to RMB 1 for a tea egg -- and they’re big sellers at this time of year, according to media reports.

Called tongzi dan (童子蛋, literally “boy egg”), they are not a mere novelty for adventurous eaters, but a local tradition listed as part of the Dongyong cultural heritage in 2008, according to a Ministry of Tofu.com translation of an article from the “Qianjiang Evening Post."

Locals say that the eggs “have the taste of spring.”

The final product with a distinct yellow tinge.The egg vendors collect the essential ingredient from local elementary schools, where teachers have long accepted the practice, according to WantChinaTimes.

Virgin eggs are made by boiling the eggs in urine, cracking the shells to allow the flavor to seep in and then soaking and boiling the eggs again. The process continues for an entire day.

"They are so delicious that I can eat 10 every day," says a woman surnamed Liu, who moved to Dongyang several years ago and developed a taste for virgin eggs. "I had never eaten them before I came here, but I am addicted to them now."

Although the popular food is supposed to help people survive the upcoming summer heat, not everyone is a fan, according to Shanghai Daily.

A Dongyang native, Mr Li, says that he has never tried the eggs, and doesn't intend to, the Ministry of Tofu blog reports,

“The smell kills me. I feel like throwing up at the thought of it. It stinks.”

The Chinese medical community is divided over whether virgin eggs have any nutritional value.

According to traditional practitioners, the food can treat yin deficiency, decrease internal body heat and promote blood circulation, but Dr. Huang Jian, who works at Central Hospital in the city of Jinhua, doesn’t support the tradition saying that “that urine is waste expelled from human body and basically contains no substance conducive to human health.”

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While the healthcare community debates, the city is pushing virgin eggs as their next big export.

“We are having a big export drive because we want people outside China to fully appreciate the delicacy of our cuisine,” says local chef and connoisseur Lu Ming.