Jimmy Doherty looks at some of the tricks food manufacturers use to maintain a constant supply of seasonal foods all year round, as he concludes his mission to unravel the scientific secrets behind mass food production.

In a bid to find out how bananas that grow thousands of miles away always arrive in the supermarket perfectly ripe, Jimmy sets up his own banana-ripening experiment. He also turns his mind to mushrooms, which normally only appear in the fields in autumn, but grace the supermarket shelves all year round.

If people relied on nature to supply salmon to supermarkets, they would find empty fridges for much of the year, so Jimmy visits a salmon farm in Scotland, where he discovers a plot to fool the fish into believing it’s summer when, in fact, it’s really winter.

Finally, Jimmy explains how sandwich ham producers make people think the pink slices are cut from a single joint of meat, rather than lots of tiny pieces squashed together.

Jimmy’s Food Factory is simulcast on the BBC HD channel – the BBC’s High Definition channel, available through Freesat, Sky and Virgin Media.

Jimmy Doherty tries to crack the secret recipe of cola manufacturers by attempting to make his own version of the fizzy drink, using such unlikely ingredients as lavender and coriander, as he continues his quest to uncover the secrets lurking in the contents of the supermarket trolley.

Jimmy builds his own production line in order to work out how you turn a humble potato into a hoop-shaped snack you can fit on your finger. He’s also in for a special treat at the world’s biggest ice-cream factory, where he discovers why it is the only frozen food you can eat straight from the freezer.

A visit to the UK’s largest crisp factory is also on tonight’s menu as Jimmy discovers how they make sure every crisp is crunchy.

Jimmy’s Food Factory is simulcast on the BBC HD channel – the BBC’s High Definition channel, available through Freesat, Sky and Virgin Media.

Today, people expect every type of seasonal food to be available 365 days a year. But the foods themselves don’t obey the demand. In tonight’s programme, Jimmy looks at the different ways foods can be stored and preserved, from freezing peas and freeze-drying strawberries to producing chilled ready meals and canned foods without adding preservatives.

Jimmy sets up his own pea-freezing factory, using dry ice and a leaf blower, and combines a vacuum chamber with space-age science to produce freeze-dried fruit. He visits one of the biggest chilled ready meal factories to discover how they cook preservative-free meals that will stay fresh for a week. Jimmy also visits the biggest baked beans factory in the world to discover how manufacturers can guarantee that, once food is sealed in the can, it stays safe for years.

Jimmy’s Food Factory is simulcast on the BBC HD channel – the BBC’s High Definition channel, available through Freesat, Sky and Virgin Media.

In the third episode of Jimmy’s quest to uncover the secrets lurking in the contents of the supermarket trolley, he finds out why there isn’t a creamy layer at the top of the milk any more.

He attempts to replicate the modern dairy process using a DIY production line set up in a barn. He uses clever chemistry to make his own version of supermarket spread and follows the egg’s journey from hen to supermarket. He is surprised to see some of the imperfect wrinkly eggs that never make it onto the shelves. At the cheese factory, he helps make Red Leicester cheese and learns that this is one factory where they actually put bacteria into the food.

Jimmy’s Food Factory is simulcast on the BBC HD channel – the BBC’s High Definition channel, available through Freesat, Sky and Virgin Media.

Jimmy Doherty attempts to unravel the

scientific secrets behind homemade sandwiches

Jimmy Doherty’s mission to unravel the scientific secrets behind mass food production continues with an investigation into the contents of homemade sandwiches.

Why does supermarket bread stay soft longer than home-baked bread? Jimmy attempts to recreate some “supermarket bread”, building his own factory mixer from a metal dustbin. He also wonders what it is about processed cheese slices that people love so much – after all, they’re only 60 per cent cheese. Could it simply be that they’re sliced-bread shaped? Back in the barn, Jimmy sets up his own processed-cheese production line to find out what the other ingredients are.

Bugs and caterpillars are rarely found in ready-bagged supermarket salad leaves so Jimmy investigates how one Wiltshire producer checks that 1.5 million bags a week are bug-free.

He is also keen to discover how supermarket suppliers grow tomatoes out of season and wonders whether they are doing anything to the fruit to be concerned about. He visits a tomato farm in Hertfordshire, where he discovers that it’s not greenhouses alone that help their tomatoes grow.

Jimmy’s Food Factory is simulcast on the BBC HD channel – the BBC’s High Definition channel, available through Freesat, Sky and Virgin Media.

Wedneday 21 October

7.30-8.00pm BBC ONE

Jimmy Doherty’s mission to unravel the scientific secrets behind mass food production takes him to the country’s leading food manufacturers. With an ambitious glint in his eyes, Jimmy then decamps to a Suffolk barn to set up his own food factory, complete with a prototype supermarket food production line.

In the first programme in the series Jimmy takes a closer look at breakfast foods. He attempts to create cornflakes from scratch using corn kernels and a mangle. Armed with a paint stripper gun he creates his own instant coffee and, during a visit to a dairy farm, he discovers the advantages of using a robot to milk cows. With a handful of sugar beets he is surprised to see how something that contains only 17 per cent sugar can be turned into the familiar sweet granules people put on their cornflakes.