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.