

There are two stronger theories for how "coffee" came to be "joe," but neither is verifiable. To believe the Josephus Daniels theory is to believe that across that span of time no one - in the Navy or outside it - wrote down that term in any newspaper article or letter that has yet come to light (and guys aboard ships are known for writing letters).
#Cup of java meaning full
Moreover, "cup of joe" was first recorded as entering the English language in 1930, a full 16 years after the grumblings of disgruntled sailing men supposedly put the term into common parlance. There are far fewer officers than there are sailors, thus the impact of General Order 99 would have been relatively mild, certainly not the stuff of which rueful sobriquets are coined. Officers, however, were affected because they had had access to a "wine mess" from 1893 until the 1914 order put a stop to that. Rather, the implementation of General Order 99 had precious little effect on the lives of enlisted sailors, an already heartily sober lot, because the ships they served on had been officially dry since the spirit ration was abolished in 1862. Navy had not been sodden with rum and staffed as far as the eye could see by tipsy sailors barely capable of remaining on their feet. It's a charming theory, but it just doesn't hold up. By the lights of the Daniels supposition, the loss of easy access to booze aboard ships led to increased coffee consumption by naval men, who in response christened their mugs of java "cups of joe" as a sorrowful homage to the man who had banned their hooch and thus forced them into drinking coffee. His General Order 99 that prohibited alcohol aboard such vessels was issued on 1 June 1914. Navy ships (albeit with some exceptions for special occasions). One theory ascribes the nickname to Josephus "Joe" Daniels who, while Secretary of the Navy during World War I, imposed a general ban upon the serving of alcohol aboard U.S. From that time on, the strongest drink aboard Navy ships could only be coffee and over the years, a cup of coffee became known as 'a cup of Joe'."

Among his reforms of the Navy were inaugurating the practice of making 100 Sailors from the Fleet eligible for entrance into the Naval Academy, the introduction of women into the service, and the abolishment of the officers' wine mess. "Josephus Daniels (-15 January 1948) was appointed Secretary of the Navy by President Woodrow Wilson in 1913.

I think the strongest explanation i've heard is: Where does the term "cup of Joe" (coffee) come from? (We colloquially term coffee "java" because at the time the beverage became popular in the 19th century, the primary source of the world's coffee was the island of Java in Indonesia.) Over its history of popularity in Western culture coffee has attracted affectionate nicknames such as "java" and "joe," and it is the latter which concerns us, because unlike the origins of the term "java," how the beverage came to bear the appellation of "joe" is still a bit of a mystery. It has fueled the productivity of countless offices and imparted warm comfort to innumerable half-frozen G.I.s, and it's been the prominent beverage in multitudinous housewifely gatherings (coffee klatches) and Alcoholics Anonymous meetings. While those of the Starbucks generation may almost think they discovered the drink, coffee, that enticing hot brew, has been part of everyday experience in Western society for a number of generations.
