Chinese, Japanese and even Westerners adore the shop's dau fu, explains the owner, Mr Leung Chun-lam. ''We sell all types of beancurd. Dau fu (fresh bean curd), dau fu pok (deep fried), dau cheung (soya bean drink) and dau fu fa (bean curd jelly), as well as jars of fermented dau fu.'' Various types of bean curd are served in different ways. The savoury dau fu or the dau fu pok is stuffed with minced meat and fried or boiled in a soup. Sweet bean curd products are served in a bowl, hot or cold, with syrup or milk.

Every day, the shop grinds about 120kg of soy beans. The beans imported from the mainland are best: ''The beans are fresher,'' Mr Leung said.

The 63-year-old businessman does not know how to make bean curd himself. He started Yau Heung with relatives and friends in 1959. ''We chose bean curd business because one of the relatives had made bean curd before and knew the trade.'' Although his relatives still have stakes in their venture, much of the business rests in Mr Leung's hands. ''They [relatives] are old now,'' he explained.

Mr Leung employs three masters to make the bean curd. ''One is in his 70s. The other two are in their 60s.'' What worries the owner is the future. ''The masters are very old and they are getting fewer, too. The younger people don't want to learn the trade. Making dau fu is too much work.'' The masters start making the bean curd at 3 every morning. The painstaking process takes three hours. And due to the high demand, it is repeated twice throughout the day.

It is not an easy trade, Mr Leung noted, and you must be physically strong. He regrets the diminishing number of masters in Hongkong. When his masters retire, he doubts if there will be replacements.

''I don't know what will happen. Although we have the machines, we need experts to oversee the production. They know the right way to stir the curd. For good bean curd, you must make sure it does not stick to the bottom of the pot. Otherwise, it will burn and have a smokey taste.'' There are only three young masters left in Hongkong, according to the Soy Bean Products Manufacturing Association. They are in their 40s.

Mr Leung sets aside his fears as he watches his customers enjoy themselves: ''The winter weather is better for the bean curd. In summer, the hot weather and humidity turn the bean curd sour faster.'' Business is always brisk, from the minute the shop opens to closing. Customers eat in, sitting on old stools and sipping glasses of sweetened soy milk or dabbing chilli on pieces of fried bean curd with chopsticks.

''Weekends are even better. The flow of customers is non-stop,'' Mr Leung added. The spill-over stands on the sidewalk, sipping from glasses or cradling bowls in their hands.

He attributed his success to the fact that there was little competition in the Causeway Bay area. ''The authorities became stricter in issuing permits five years ago. They are worried about air pollution.

''Our shop is subjected to strict hygienic inspections by the authorities. You have to be very clean.'' So the shop is always spick and span. And what is as consistent as the loyal customers, is the fresh fragrance of dau fu, just what the name in Chinese means.