Great brewing is partly science and partly art.  Brewers can draw on a dazzling variety of raw materials to brew with beers with widely different appearances and flavours.  Over the past few years, both Hall & Woodhouse and Marston’s have been at the forefront of the development of  new and interesting beers to enthuse their customers. Toby Heasman and Richard Westwood will describe how they choose which materials to use – and the impact of using different types of malt and hop varieties on beer quality.