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.

Gregg Wallace follows 27 tonnes of potatoes from a farm in Hampshire through the largest crisp factory on earth.

Gregg Wallace helps to unload 27 tonnes of dried haricot beans and follows them on a journey through the world's largest baked bean factory.

Gregg Wallace visits Britain's largest bicycle factory, which produces 150 folding bikes every day, and joins a production line to make his own bike.

Gregg Wallace helps to unload a tanker full of sugar from Norfolk and follows it through one of the oldest sweet factories in Britain.

Gregg Wallace visits the UK's largest sports shoe factory to see how they produce 3,500 pairs of trainers every day.

In this Christmas special, Gregg Wallace, Cherry Healey and Ruth Goodman explore the fascinating factory processes and surprising history behind our favourite festive treats.

Gregg Wallace receives some tea leaves from Kenya and follows them through the factory that produces one quarter of all the tea drunk in Britain.

Gregg Wallace is at the world's largest dried pasta factory in Italy, where they produce 150,000 kilometres of spaghetti each day.

Gregg Wallace follows the production of chocolate digestives and discovers that we are all eating them the wrong way up.

Exploring the fascinating factory processes behind Christmas cake, baubles, brandy and more. And why Christmas tree lights are called fairy lights.

Gregg Wallace explores the Grimsby factory that processes 165 tonnes of fish a week and produces 80,000 cod fish fingers every day.

Ruth Goodman investigates the origin of Worcestershire sauce, as told by Mr Lea and Mr Perrins.

Gregg Wallace explores Ribena's Gloucestershire factory. Meanwhile, Cherry Healey is in the lab figuring out why fizzy drinks are so appealing.

In this Christmas special, Gregg Wallace visits a factory which produces a staggering two million tins of festive chocolate assortments a year.

Gregg Wallace is in Nottingham at an enormous party food factory where they produce 200,000 canapes every 24 hours.

Gregg catches up with the Essity paper mill in Manchester, which he visited back in 2018. The coronavirus crisis caused a huge spike in toilet roll sales.

Gregg reconnects with the Heinz baked beans factory in Wigan which he visited back in 2016. The coronavirus crisis caused a massive spike in the sales of tinned goods, and the baked beans factory upped production to deliver almost 50 million cans in just one month, nearly double the amount of tins they would normally sell in the same period.

Gregg reconnects with the Walkers crisps factory in Leicester, the largest crisp factory in the world, which he visited back in 2016. We Brits love a snack, and when the coronavirus crisis hit, sales of packet treats rose by 32% as shoppers spent more than £63 million in just one week.

Gregg reconnects with the Typhoo tea factory in the Wirral near Liverpool, which he visited back in 2017. The coronavirus crisis caused tea bag sales to soar, and the factory has upped production to produce 109 million tea bags in a week, an increase of 28 million. Throughout the episode, Gregg looks back over his original visit to the factory and the whole production process. First, he helps unload 24 tonnes of dried tea from Kenya and then follows its journey through the 28,500-square-metre factory to make the nation's favourite - good, old-fashioned builder's tea. Meanwhile, Cherry Healey travels to Kenya to see how the tea crop is picked, processed and shipped over 4,000 miles to the UK. She also learns how to master the art of making the best tea bag brew, revealing the top tips for a perfect cuppa. And historian Ruth Goodman explores how tea kept up morale during World War II.

Gregg Wallace reconnects with the McVitie’s factory in Harlesden, north west London, which he visited back in 2017. The coronavirus crisis caused a huge spike in the nation's desire for sweet treats, and sales of the firm’s chocolate digestives rose by 71 per cent, meaning in just two months, they sold an astonishing 12.5 million packets.

How Woodmansterne produces 35 million greeting cards a year in Watford - from sketching a card design, to creating an aluminium plate for printing, to guillotining the sheets into cards and the final shipping process. Creating a vegan Christmas feast. The history of the year Christmas was cancelled.