A tour of the Aldi chocolate factory in Preston, how many revolutions to whip up a Milky Way, chocolate-dipped grasshoppers and locusts, and a life-size chocolate Boris.

At Prestat, owner Nick is proud of his Royal Warrant, but also of the company's place in history as inventors of the chocolate truffle in 1895. Cameras focus on the expertise which makes these chocs fit for a Queen. There's also a profile of Mackintosh's, creators of Quality Street, Rolo and more. Plus, a nostalgic look at the most romantic ad ever, as voted for by the public. Finally, the ultimate chocolate cocktail contest - Cadbury's Roses Strawberry Creams versus Quality Street's purple one.

Examining the story of Fry's, which created the first chocolate bar in 1847, and a look at the sales of dark chocolate which are on the rise. Cameras visit one of the factories that pioneered this sophisticated new wave in the UK, Sussex-based Montezuma. There is also a look at the creation of a near life-size chocolate Elvis.

Food giant Nestlé opens the doors of its Perugia factory in Italy, where production manager Davide looks into the secrets of what is undeniably a labour of love. Chocolatier Prudence Staite has a big challenge ahead, creating a full-blown chocolate replica of a much-loved vintage motorbike for the National Motorcycle Museum in Solihull, as it celebrates its 35th birthday.

A look at the history of rivalry between different brands of chocolate biscuits and a behind the scenes visit to a Norfolk factory that produces 35,000 walnut whips every hour. Plus, a look at how chocolate became a much-needed taste of home for soldiers serving in the First World War, the story of the world's tallest chocolate fountain, and a chocolatier who was challenged to create a sculpture of an ancient Roman god for a festival.

A visit to the Nestlé factory in Perugia, Italy, where the Crunch Bar is made, and the outpost of Barry Callebaut, the biggest chocolate supplier in the world, which is next door. Emma and Mark Baravelli, chocolatiers from Conwy in North Wales, are given a challenging brief - to carve a life-size baby bison for Lord Newborough's 70th birthday - while there's also a trip to Eurochocolate, the biggest chocolate festival in the world.