Gregg Wallace discovers how one of Britain's largest bakeries makes up to one and a half million loaves of bread each week. Following the production of one of the UK's favorite loaves, he learns how it is possible to bake 4,000 loaves at once and how a machine can bag a loaf of bread in midair. Cherry Healey takes us inside one of the largest flour mills in the UK to see how the perfect flour is made and reveals the science to storing bread at home....