Chef and food writer Jeremy Lee indulges his passion for raspberries by returning to his native Scotland to meet raspberry growers, pickers, processors and breeders. He explains how a mysterious combination of soil, rainfall, temperature and sunshine has produced the 'terroir' that makes Scotland the perfect place for that particular crop. In the 1950s, the Raspberry Express train brought Perthshire 'rasps' every day from Fife to Covent Garden in London, but since those days the growers have faced competition from eastern Europe and from Spanish varieties as well as the ever-present threat of root disease. How have the growers adapted to changing markets? Jeremy finds optimism in the air, as demand for home-grown raspberries continues to grow.