CHANGSHA, June 25 (Xinhua) -- Shi Qingxiang, 42, is colloquially known as "Tofu Beauty," not because of her looks, but because she is a master tofu maker.

Tofu, one of the most common and least expensive foods in markets all over China, is the source of extra income for villagers in central China's Hunan Province.

Shi operates the only homemade tofu factory in Pinglang Village, home to the Miao ethnicity for hundreds of years. The unique quality of mountain spring water and homegrown soybeans has made Pinglang tofu famous near and far.

"Our tofu is so fragrant and sweet that no dipping source is even required," she said.

Historical records show that local soybean planting and tofu making began about 300 years ago, when the exchange of products and techniques between Miao and Han people was encouraged.

Shi's grandfather Shi Guangyao, 81, said the village was already famous for its tofu at the time of his grandfather. He recalls that travellers used to always stop to try Pinglang tofu.

"As the old saying goes, there are three sufferings in life: poling a boat, forging iron, and making tofu," Shi Guangyao said. Making tofu is extremely laborious with little profit.

Starting from the late 1990s, more and more young people, including Shi Guangyao's four children, left the village for jobs in cities. But he couldn't part with the stone mill he inherited from his father and continued to use it, making tofu for his children when they returned home for spring festival.

In 2009, Shi, the youngest daughter, returned home and opened a restaurant with her husband, using her entire savings from years of working in the city. Her flagship dish was her family's tofu.

The market response was surprisingly good. "Some customers queued for hours just for a bite of our tofu," she said.

Shi's success inspired a local poverty alleviation team to help her register and promote the "Pinglang Tofu" brand. Pinglang Tofu was later added to the protection list of ethnic traditional culture.

At a New Year gifts fair in Changsha, the provincial capital, in 2012, Shi's tofu became a hit. The on-site tofu-making presentation also drew a lot of attention, as well as a few business cooperation opportunities.

"We sold out of a week's stock on the first day," she said.

Through the efforts of the poverty alleviation team, the village's drinking water project was completed. Spring water now runs directly into every household. In addition, a number of tourism-related infrastructure was built at the same time.

In December 2014, Shi and her fellow villagers opened a cooperative and introduced advanced packing machines. Dried and vacuumized tofu products have been developed to extend the length of preservation and boost sales.

Over 30 villagers, including 20 registered low-income ones, have joined the cooperative. Last year, the net income topped 800,000 yuan (120,000 U.S. dollars).

"I was embarrassed if anyone called me 'Tofu Beauty' in the past. But I now realize it's a compliment and I should continue to work hard to be worthy of it," she said.