Amateur bakers embark on a set of challenges designed to test every aspect of their skills and showcase the exacting science behind the art of baking. Mel Giedroyc and Sue Perkins are on hand to encourage them and cast light on the history of British baking. Meanwhile the judges, renowned food writer Mary Berry and professional baker Paul Hollywood, scrutinise every crumb, flavour and soggy bottom of the baker's efforts in order to award one with Star Baker and send another home.