Dim sum trolleys winding their way around restaurant tables might soon become a memory, as computers take over the orders. Only a few restaurants and teahouses still serve the traditional morsels in the old way, with most preferring to give order sheets to customers who tick a selection of boxes. Restaurants that have made the change say the new method is more efficient, more hygienic and less wasteful as the dim sum are steamed to order. But some restaurateurs are clinging to the old method, believing their customers prefer it. 'My father ordered me not to change anything,' said Ngan Chuen-fai, operator of the Lin Heung in Wellington Street, Central, which was founded in 1927. 'So, I will just continue to operate the business as it was started by my father,' he said. Not only the dim sum carts but also the decor at Lin Heung recall earlier times, with no carpets or grand decorations, just a worn tile floor with spittoons under the tables and ceiling fans whirring above. Framed calligraphy listing some dishes and dim sum on offer is posted on the walls. Male waiters dressed in white uniforms rush around with metal kettles to refill the teapots, while women push trolleys with towers of small bamboo steamers, calling out the names of dim sum. But even that is a change from the restaurant's early days. Mr Ngan said that in the 1950s and 1960s waiters would carry dim sum in big bamboo steamers suspended from a strap around their necks. 'Many teahouses used to occupy two to three floors. To make it easier to carry dim sum around, workers carried big bamboo steamers with a couple of dozen dumplings,' he said. Dim sum trolleys made their first appearance in the 1970s when more teahouses began doing business on a single floor. 'Lin Heung used to have three floors and now we only have one and so we adopted trolleys too,' Mr Ngan said. He said there was also a sound business reason for using the trolleys. 'We can decide what customers eat instead of giving them choices, as they can only choose dim sum from trolleys. We can therefore place expensive and cheap dishes on one trolley,' he said. 'Many restaurants offer cutthroat discounts, because customers always order cheaper dim sum which means little profit can be generated. Food quality therefore suffers, as they have to cut costs.' Estates' Restaurants (Hong Kong) Merchants Association's Chan Cheung-chor, who has been in the industry for 46 years, said dim sum trolleys were unhygienic. 'Customers often ask dim sum waitresses to lift up lids to let them check before they actually take the food. Saliva flies around the dim sum. Some might just cover the dim sum again when they change their mind,' he said. '[With computers] the quality is better, as it is all freshly made. Food waste is also reduced. When we used trolleys, some dim sum might be left unsold and we had to throw it away in the old days. 'Customers also do not have to endure a long wait for their favourite dim sum. The same set of dim sum on a trolley might circle around for 30 minutes before the next round comes.'