Chocolate was a drink in Germany until around the middle of the 19th century: the wealthy and aristocrats enjoyed their cocoa by the cupful. The invention of Coenraad Johannes van Houten's cocoa butter press in 1828 has so far been regarded as the birth of edible chocolate, but now a scientist at the University of Kassel has found evidence of an even earlier consumption of chocolate in the shape of a ball - in letters written by the Brothers Grimm.