Top-class chefs have begun to realise that if they want to conjure up that extra-special souffle or mouth-watering dessert, the person to turn to is a molecular scientist. Quentin Cooper talks to chef Heston Blumenthal and physicist Peter Barham about their collaboration to create exotic concoctions such as crab ice cream. Producer John Watkins. E-MAIL: material.world@bbc.co.uk Webwatch: page 39