The Chongming rice wine, which is one of the most acclaimed specialties on the island, features a distinctive sweet taste. [Photo provided to China Daily]

By mixing and brewing the locally produced glutinous rice with qu, a special yeast made from Chinese herbs for fermentation, the wine features a distinctive sweet taste similar to ice wine but a much stronger aftertaste close to spirits, despite its low alcohol content, usually less than 15 percent.

"The unique taste of laobaijiu has made it a hit among both males and females because it is sweet yet strong," Yu said. "Once people get a sip of it, they are just hooked."

In fact Yu reckons he grew up in the aroma of the wine.

Last year his wine sales were worth 3 million yuan, up 20 percent from the previous year, he said.

In the difficult years, as a cost-saving measure, Yu had no retail space or sales staff, and he managed to sell most of his produce, at between 136 yuan and 276 yuan a kilogram, on the phone to visitors who had been to Chongming and drunk his laobaijiu in local restaurants.

In a BBC travel and food program about Shanghai hosted by Rick Stein last year, Yu's wine featured, together with soup dumplings and pork lard scallion oil pancakes as the city's culinary specialties.

As for the ambition to compete with and even beat Moutai, Yu said he has not given up.

"However, it's no longer about sales. I think I've earned my pension. I just hope that one day when people talk about Shanghai, laobaijiu will be something that is as much a signature for the place where it is made as are Moutai and Champagne."