"It's quite nutritious and good for your stomach. And it's best if you drink it in the morning," Wang says.

Taiyuan residents used to go for tounao before sunrise. So, restaurants that served the dish would hang red lanterns－a tradition that remains.

Elderly people in particular appreciate the liquor fragrance. Some drink bowls of yellow liquor along with the soup.

Wu Fusheng has joined friends to eat tounao for breakfast at Renyili restaurant three to four times a week from October until March for nearly 20 years.

"With a bowl of tounao and yellow liquor in your stomach, you feel warm and comfortable in the wintertime," Wu says.

"If you eat a bowl of tounao in the morning, you don't feel hungry at noon."

He considers enjoying tounao in winter to be a healthy form of leisure.

Zhai Dehou says he has heard about the dish frequently since he moved to Taiyuan at age 14. The 87-year-old can recall the three locations Qingheyuan has moved among over the years.

The restaurant offers a deal for diners over age 70, Tongluowan branch manager Gao Zhenrong says. They can get a bowl of tounao and a basket of shaomai (flower-shaped steamed dumplings) for 25 yuan ($3.6).

The dumplings have thin wrappers, and are filled with lamb, beef and leeks."They pair well with the soup," Gao says.

He says plunging temperatures lead to surging orders. His restaurant can sell between 800 and 1,000 bowls a day, and up to 1,500 at most.

"The price of lamb has increased from 44 yuan to 70 yuan per kilogram. But we haven't raised the price of our tounao or skimped on the ingredients," he says.

Gao believes the fact that many customers travel dozens of kilometers for a bowl shows how important tounao is to Taiyuan's residents.

"It has a special flavor that lingers in the memories of Shanxi's people," he says.