CHOCOLATE is one of life's most sensual pleasures, yet its making is clinically precise. That Easter egg only looks and tastes good because its maker is versed in science as art. Even at Easter, when demand outstrips supply, patissiers never lose their cool. Their kitchens must remain at 20 degrees Celsius or chocolate becomes unworkable. At the Mandarin Oriental, as pastry sous-chef Christian Labrosse explained, temperature maintenance was so crucial the kitchen doors were always closed. ''Humidity causes a white film to form, and too much warmth makes raw chocolate too soft. Conditions must be perfect or the final texture, colour and taste can be affected,'' Labrosse said. Chocolate sales are increasing every year in Hongkong. ''People travel and are demanding more variety,'' Labrosse said. ''Both guests and locals are becoming more knowledgeable.'' Estimates of this year's sales vary from 200 kilograms at the Grand Hyatt to 900 kg at the Holiday Inn Golden Mile. The Island Shangri-La expects $80,000 worth of business at its Island Gourmet shop. A number of hotels have added chocolate kitchens during expansion, as demand is now big enough to justify in-house production. Hotel sales outlets are also being enlarged to showcase the new, artfully-packaged chocolate ranges. The Hilton's Gourmet Corner and the Mandarin Shop were redesigned two years ago, and The Peninsula now sells its chocolates in Seibu and The Landmark. All forms of filled and shaped chocolate begin life the same way. A large block of pure chocolate made from cocoa powder, cocoa butter - products of the cocoa bean - sugar and a little vanilla is broken into pieces and melted. Milk chocolate has less cocoa powder and uses milk powder, while white chocolate has no cocoa powder and more sugar. Premium grades come from Europe, with the connoisseurs' choice being Swiss, Belgian or French. ''In Hongkong, people prefer milk chocolate because it is sweeter. In Europe, bitter dark chocolate is most popular,'' Labrosse said. The blocks are melted slowly in a large vat at precise temperatures. It requires careful monitoring. ''First it must be heated to 45 C, then cooled to 24 C, then heated again to 28 C,'' Labrosse said. ''Temperatures must be exact or the chocolate can separate and lose its shine.'' Once melted, the next stage is determined by end design. For moulded eggs and rabbits, liquid chocolate is poured into the moulds and tipped out again immediately. If the consistency is correct, only a three-millimetre layer will be left in the mould. Three-colour chocolate designs are more painstaking. For example, dark and white details - such as eyes - on a milk chocolate rabbit must be done first and left to set. Setting at the Mandarin takes place in a huge, walk-in fridge. It is digitally controlled so the temperature remains between 16 and 19 C. Moulded Easter designs are the most popular in Hongkong, but reputation is built on hand-made creations. ''Everyone can buy the same moulds, so coming up with new designs is the real challenge,'' Labrosse said. ''It's fun, creative and gives a chef their signature style.'' At the Mandarin, preparations for Easter begin at least two months in advance. Designs are submitted to department managers for tasting and those chosen veiled in secrecy. ''It's very valuable to get feedback,'' Labrosse said. ''Tastes vary so much. In France, for example, my liqueur-centred chocolates were in demand, but they're not liked here.'' Localisation came in the form of a sampan last year. This Easter, a chocolate telephone with Smartie push-buttons sold well. Possible future designs include a tram. At the Island Shangri-La, pastry chef Alain Guillet chose a fairy-tale theme to exhibit his artistry, while a variety of chocolate baskets and Easter egg halves filled with truffles and mini eggs appeared at most outlets. Small designs may regularly prove the best sellers, but for true chocoholics big is best. This year's choice included 4 kg rabbits for $1,200 at the Mandarin and a 40 centimetre by 20 cm Easter house for $1,100 at the Grand Hyatt. Over the past week, Labrosse has supervised the production of 120 kg of chocolate every day. While most chefs claim they rarely eat because they work with food all day, the Frenchman said he loved chocolate. ''People may say I eat too much, but I believe dark chocolate is good for stress.''