Million dollar idea: The chocolate bar
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How the chocolate bar became a million dollar idea

14 February 2019 Last updated at 23:57 GMT

Nowadays, the world spends close to $100bn a year on chocolate bars, making them one of the most popular snacks in history.

But for centuries, chocolate had only been a drink. No one knew a way of making it into a solid food. That is until a 19th Century Englishman - Joseph Fry - worked out how to do it.

Aaron Heslehurst now explains.

Video producer: Jeremy Howell