How a cheese factory in Gateshead produces 3,000 tonnes of spreadable cheese every year - making cheddar, chopping and blending it with whey, water, and other ingredients. How bacteria affect the aroma, flavour and appearance of cheeses. How to make perfect cheese on toast. How cheddar became the predominant hard cheese world wide. How Kraft made processed cheese 100 years ago.

How a bakery in Cornwall produces 180,000 Cornish pasties a day. There are rules: A Cornish pasty must be made in Cornwall; the filling can only contain onion, potato, swede, beef and some seasoning; and each ingredient must be cooked from raw within the pastry parcel. The versatility of onions, and how they make us cry. How anaerobic digestion turns food factory waste into electricity. Challenging the pasty's origin story. How importation of pepper eventually transformed it from a precious commodity to a spice that everyone could afford.

How Guinness make two million litres of Irish stout every single day. How reservoir water is treated to provide clean drinking water to the people of Dublin, as well as to the stout brewery. How hops are harvested at a farm in Worcestershire. The history of Irish pubs, and how pub games helped the Allies in the Second World War.

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

How a factory in Manchester produces 700,000 toilet rolls a day starting with spruce timber offcuts from Sweden, pulped and rolled onto 1.2-tonne 'mother reels'. How the water treatment works of Brighton remove debris, grease and bacteria to produce clean water in little more than an hour. How a high-tech Japanese toilet addresses hygiene. How waterless toilets could improve sanitation for one-third of the world's population. The history of the modern flush toilet.

How a factory in North Yorkshire produces 625,000 sausages a day, using machines that can fill 600 sausages in a minute. How low and slow shallow frying delivers the best combination of flavour, moistness and succulence. How veggie protein is created from a tiny speck of natural fungus. How a 'meat sock' is the secret to wrapping a Scotch Egg every three seconds. How German bratwurst became top dog in America, and how German immigrant Charles Feltman originated the hot dog. Cooking up a 2,000-year-old recipe for sausages. How the Romans contributed by importing pepper, bay leaves and other spices that spike modern sausages.

How a factory in Lowestoft produces 450 tonnes of frozen food each day. The differences between waxy and floury potatoes, and which you should use for which job. How the potato's nutritional value compares to other fruits and vegetables. The history of potatoes is traced to Spanish explorers and an enterprising French chemist called Parmentier, who popularised the exotic new vegetable. How Mr Whippy ice creams inspired the potato waffle, a teatime treat.

How a Leicester factory makes one and a half million socks annually. What causes smelly feet, and which socks tackle it best. How a cotton spinner in Manchester produces 4,200 miles of yarn every hour. A revolutionary eco-cotton supplier. The history of 1980s sock fashion, and how the 'Kitchener stitch' helped save the feet of British soldiers in the trenches during the Great War.

How Nestle make more than eight million bars of chocolate every day in York - the UK's city of chocolate. How a cocoa plant quarantine facility in the Berkshire countryside is preventing a worldwide chocolate shortage. The bitter history of drinking chocolate.

Paddy McGuinness visits a factory in Northern Ireland to learn how they make more than half a million sausage rolls every day. Cherry Healey discovers how black pudding is made, while historian Ruth Goodman reveals how the humble sausage skin gave a surprising lift to a weapon of war.

How a factory in Italy produces 400,000 frozen pizzas each day. The science that makes mozzarella work so well on pizza. How pork is transformed into pepperoni. How freezer ships and trucks create the worldwide cold chain that enables this business to exist. How pizza was first popularised by a restaurant in London’s Soho in 1965

How a factory in France produces 336,000 croissants every day - from the 21 tonnes of butter, to the 83-year-old strain of yeast that packs a flavourful punch, to the layering of very thin slices of butter between sheets of dough to create the famously flaky texture. How croissants are best served - and eaten. How 'concentrated' butter produced in north Wales enhances the shelf life of croissants. The history of the croissant, thought to originate from 17th-century Austria, and emerging in its modern French form as late as 1906. How bread played a vital role in the French Revolution.

Gregg Wallace, Cherry Healey and Ruth Goodman look at the production, science and history of bread in Britain.

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

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

How a factory in Derbyshire produces 175,000 jars of instant coffee every day, from green coffee beans to the freeze-dried final product. How roasting alters the chemical composition of coffee. How caffeine affects the body and brain. How climate change is affecting coffee harvests worldwide, and the coffee species that could cope with warmer growing conditions. The history of instant coffee going back to the American Civil War. How passion for coffee led to the founding of the Stock Exchange, auction houses and newspapers.

How Britain's biggest brewery produces 3 million pints of beer a day in Burton upon Trent. How four basic ingredients – water, malted barley, hops and yeast – are manipulated to make dark, heavy ales; light, fragrant lagers; and everything in between. How the hard water of Burton – perfect for brewing flavourful stouts and porters – and its position on the canal network made it the centre of brewing in 19th-century Britain. How beer-making turned from a predominantly female cottage industry to an industrialised process dominated by men.

How a factory in Stoke-on-Trent produces 250,000 little cherry bakewell tarts every day - from what makes a shortcrust pastry 'short' to the team of 12 precisely placing the cherry on top of every one by hand. How to swerve a soggy pastry bottom when baking pies and tarts at home. How almonds are roasted and milled into almond butter ready for toast. The origin story of frangipane, the fragrant almond filling used in cherry bakewell. How the modern cherry bakewell actually descends from a mistake.

How a foundry in France produces a cast iron pot every five seconds - from the arrival of 20 tonnes of crude iron right through to brightly coloured orange casserole dishes. How a South African iron ore mine - one of the largest in the world - produces a staggering 670,000 tonnes every day. The science behind cooking the perfect casserole - more cooking time isn't always better. The history of one-pot cooking to prepare simple meals, from communal ovens to 1970s slow cookers. How casting iron in sand moulds democratised the kitchen through affordable cookware.

New presenter Paddy McGuinness visits a factory in Lincoln to explore how they make 500 million packs of Quavers every year. Cherry Healey learns how Bombay Mix is made, while Ruth Goodman reveals the wartime story behind our love of cheese flavouring.

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, Cherry Healey and Ruth Goodman look at Britain's love of chocolate and visit one of the world's largest chocolate factories in York.

Gregg Wallace, Cherry Healey and Ruth Goodman look at Britain's history with milk and visit one of the largest fresh milk processing plants on earth.