B for "Bordeaux mixture"

"A to Z from Sol" – your guide to some well-known or less-known interesting and unexpected facts about wine. Maybe you will learn something new, maybe you will remember something you have forgotten, either way read on and as always feel free to share your thoughts in the comment section.

Bordeaux mixture (fr. bouillie bordelaise) 

Mix copper sulfate with slaked lime in right proportions and there it is! Famous and effective fungicide, used by winegrowers to prevent infestations of all sorts (downy mildew, black rot etc.). Invented in the Bordeaux region of France (thus the name) in the late 19th century, this bluish liquid is sprayed on grapes, but only as a preventive measure, apparently it doesn’t work if you use it after the fungus had been found.

France being France there is of course a less scientific but much more romantic story about the origin of la bouillie bordelaise. As the legend goes thieves were a nightmare for wine-makers at that time, so to prevent them from stealing grapes, winegrowers came up with this special liquid. Light blue color of the mixture made the grapes look  less appetizing for thieves. How credible this story is, that’s for you to decide.