Inside the Factory: How our Favourite Foods are Made

Gregg Wallace discovers how one of Britain's largest bakeries makes up to one and a half million loaves of bread a week, and Cherry Healey goes inside one of the largest flour mills in the country to discover what it takes to make the perfect flour.

Gregg visits a chocolate factory in York where he follows the 24-hour journey from bean to bar. Meanwhile, Ruth reveals what it was like working in factories before machines.

Gregg visits one of the largest fresh milk processing plants on Earth to see how they get milk from a cow to the carton within 24 hours. Ruth reveals the tough life of a dairy maid.

Gregg Wallace receives a load of corn fresh off the boat from Argentina and follows its journey through the largest breakfast cereal factory in Europe as it is cooked, milled and flavoured to become Crunchy Nut Cornflakes. He'll discover how they can produce more than a million boxes of cereal every 24 hours and distribute them all over the UK, Europe and across the globe, as far away as Malaysia.

Gregg Wallace follows 27 tonnes of potatoes from a farm in Hampshire through the largest crisp factory on earth, as they are peeled, sliced and fried to make more than five million packets of crisps every 24 hours. Once the crisps are flavoured, they are put into bags in one of the craziest rooms Gregg has ever seen, with over 100 machines that can fill hundreds of thousands of bags every hour.

Gregg Wallace helps to unload 27 tonnes of dried haricot beans from North America and follows them on a one and a half mile journey through the largest baked bean factory in the world which makes more than three million cans of beans every 24 hours. He'll discover how a laser scrutinises every single bean; how the spice recipe for the sauce is a classified secret known only by two people; and, most surprisingly, how the beans are cooked in the can in a room of giant pressure cookers.