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 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.

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 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 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.

How a factory in Wigan produces two million tins of soup a day. Vegetable soup is followed from a pea harvest in Yorkshire right through to the finished soup going into cans and being dispatched. How the vitamin content of frozen vegetables can greatly exceed that of fresh. How a spinach soup based on a 17th-century recipe doesn't much resemble soup as we know it today. The history of the soup kitchen.

How a factory in Ireland produces 540,000 bottles of liqueurs a day. From grain, to barrel aging, to mixing cream and whiskey together, the show traces the production of a cream liqueur over the span of three years. How Ireland’s bottles and jars are recycled at a plant processing 500 tonnes every day. How all alcoholic drinks - not just aperitifs - stimulate appetite. The rules for producing and labelling whiskey, bourbon, and blends. How monks invented liqueurs. The impact of modern distillation methods on traditionally made alcohols like Irish whiskey.