How Thoughtful of Them
Prohibition turned many citizens into everyday criminals, many by way of homemade wine. Grocers could sell grape concentrate, an item which in and of itself lacked any alcohol. However, if treated in a certain way, grape concentrate would ferment, turning into wine. In order to “avoid” this outcome, many grape concentrate packages were labeled with a warning — outlining exactly what “not” to do in order to ensure that your grape concentrate did not ferment.
Source: http://nowiknow.com/liquor-sicker/
Cheers!
With Love,
Russ
Russ Towne's A Grateful Man 
ah, interesting!
Fascinating indeed