File photo shows Yang Dengyan, the first president of Quanjude Group, slices Quanjude's 196 millionth roast duck during a ceremony to celebrate the 150th anniversary of Quanjude Beijing Roast Duck Restaurant at its Qianmen Branch in Beijing, July 2, 2014. [Photo/Xinhua]

Although the lunch rush is over, chefs at Quanjude Peking Roast Duck restaurant in central Beijing are still busy serving their famous poultry.

Roast duck, also called Peking duck, is famous for its crispy skin and tender meat. The duck is sliced in front of diners by the chef, and the meat is eaten wrapped in pancakes with scallion, cucumber and sweet bean sauce.

Established in 1864, Quanjude follows a tradition of using open wood-fired ovens to roast the duck until its skin is golden and crispy. The open oven roasting method was originally reserved for duck served in the imperial palaces.

Last year, Quanjude Group, founded in 1993, sold more than six million ducks and served nearly 20 million diners.

Wu Yubo, chief roast duck chef at Quanjude, said although many restaurants sell roast ducks, not all of them are high in quality.

"Quanjude has its own bases for raising ducks, and 30 processes are used in processing and cooking each duck. Also, franchise restaurants have the same standards for duck quality, slicing skills and attractive presentation on the plate," Wu said.

As a brand with more than 150 years of history, Quanjude is well aware of the challenges in the market, said Wu.

"The youth do not inherit their preferences from older generations but have their own taste," Wu added.

The chain has learned to adapt to changing tastes. In the 1970s, Peking duck was served as soon as the duck was taken out of the oven. However, in recent years, customers have preferred good presentation of duck slices on the plate.