We are all, secretly or openly, obsessed with sweet things. From the very earliest human societies - there is evidence that Neolithic people made sweets - to modern day, there is nothing more likely to get your juices flowing than a sweet. Tim Richardson's research has taken in the whole world and all of history. So we read that the Aztecs mixed chocolate with blood in sweet libations to their gods, Saladin entertained Richard the Lionheart with exotic sherbets and sugared jellies in 1191, Victorian sweet magnates built the towns of Bournville and Hersheyville as special housing for those who make sweets, and in the 21st century we discover that the production of sweets is an extremely high-tech industry shrouded in the kind of secrecy which would make Willy Wonka blush.