Each year, weeks before Tomb Sweeping Day, which falls on April 4, people in Shanghai wait in line for hours to buy qingtuan, or green rice balls, at Xinghualou, a Shanghai time-honored bakery brand.

This year, due to the impact of the COVID-19 epidemic, the queueing time is much shorter than previous years, only about 10 to 15 minutes. But the time-honored brand has done well online.

In March, the number of fans of Xinghualou's online flagship store on Alibaba's e-commerce platform, Tmall, has reached 406,000, with turnover surging 341 percent year-on-year.

Other time-honored brands born in Shanghai have also achieved remarkable online achievements recently, such as Bright Dairy, one of the leading dairy makers in China, and Hengyuanxiang, China's leading woolen wear producer.

According to Zhi Jing, deputy general manager of Xinghualou, in 2016 the bakery created a new type of qingtuan stuffed with dried meat floss and salted egg yolk, which quickly became a top product.

However, in the past, consumers could only buy this kind of qingtuan at physical stores. To solve this "pain point", after 545 days of formula development, Xinghualou launched the qingtuan with dried meat floss and salted egg yolk online at its Tmall flagship store at the end of February.

With the resumption of express deliveries, Xinghualou's Tmall store has sold 800,000 qingtuan, with turnover exceeding five million yuan ($703,000), since March.

In recent years, e-commerce has driven the cross-boundary innovation of time-honored brands, and those brands have opened new markets through new retail methods. Statistics show that since the outbreak of the epidemic, there have been 12,000 offline brands opened on Tmall stores, more than 500 of which are from Shanghai.