After taking his seat on a Ningbo-Shanghai bullet train around 2pm, Zhang Zifan, a 26-year-old programmer bound for Shanghai, fished out a small bottle of still-chilled Grenache from his shoulder bag.

"I bought this 250ml wine from the supermarket near my hotel yesterday evening and chilled it in the hotel-room fridge. Now, it's going to refresh me during this 300-kilometer, three-hour journey," said Zhang.

A small bottle of wine costing less than 100 yuan ($15) is Zhang's remedy for a tiring business trip. Many of his young friends also have formed the habit of carrying a bottle of wine on work-related trips, he said.