Inside the Christmas Factory 2017

Exploring the fascinating factory processes and surprising history behind our favourite festive treats. Gregg Wallace follows 24 hours of production at a cake factory in Oldham, near Manchester, where this year they will make two million Christmas cakes for Marks and Spencer. Cherry Healey is given special access to Britain's largest marzipan factory, which produces two thousand tonnes of almond paste every year, and visits one of our largest sprout farms where, during the two weeks before Christmas, they pick 190 million sprouts. Ruth Goodman adds her own Christmas revelations by investigating how our early industrial heritage inspired Charles Dickens to write a Christmas Carol, and why we call Christmas tree lights fairy lights.