Peter began his career as a candle maker in his native Vevey, Switzerland, but soon demand fell due to the emergence of oil lamps.
When Peter came up with the process of making milk chocolate in 1857, he had a problem with removing the water from the milk, which caused mildew to form. It was not until he enlisted the cooperation of Henri Nestlé, then a baby-food manufacturer, that finally, in 1875 after seven years of effort, he was able to bring the product onto the market. Later, in 1879, the two joined to form the Nestlé Company.
^"Toms: Chokoladens historie" (in Danish). "Peter Daniel fra Nestlé i Schweiz opfinder videre ved at tilføre mælkepulver i chokolade, og laver dermed den første mælkechokolade i 1875. English translation: Peter Daniel from Nestlé in Switzerland invents further by adding milk powder to chocolate, thereby producing the first milk chocolate in 1875."
^"Cocoa", Encyclopædia Britannica. Encyclopædia Britannica Online Academic Edition. Encyclopædia Britannica Inc., 2013. Web. 9 May. 2013.