This is actually an expanded excerpt from an earlier post. Someone recently asked why I was so cool on Jerry Thomas. I thought that this except might explain it best.
Why Thomas shook his Whiskey Cocktail and bruised the velvet of the liquor with aeration, even though he stirred his Brandy Cocktail, is not something that I can begin to understand. I have often doubted that Jerry Thomas ever really did work as a bar-tender in California during the gold rush. I think it is likely he only said so in New York to get hired as a bar-tender there. I believe he asked a real bar-tender to tutor him before going off to sell himself. What — someone lying about their experience to get their first job tending bar!?!? Unheard of!!!
His book never even mentions Pisco brandy in the slightest sidebar — then unknown in New York, but just about San Francisco’s most commonly poured spirit! That, plus his proven proclivity to boldly lie (I invented the Tom & Jerry/Martinez/etc.) and all the nonsensical mixological idiocies in his book (compared to just about every other 19th century book on the subject) smack of him being tutored quickly and often getting his notes wrong (or perhaps of the bar-tender tutoring him putting in little bits on nonsense intentionally). How else do you explain his sour with the juice a quarter lemon (up to maybe about 7.5 ml. with lemons of his day) but a full tablespoon (15 ml.) of sugar when everyone else in the 19th century uses at least 3 or 4 dashes (15 or 20 ml.) of lemon juice? And that’s not an exception — such is found throughout his book.
I think that there are two reasons so many revere Thomas today. The first is that the earliest book on the subject was published under his name. The second might be that bar-tenders don’t really know traditional American mixology very much any more — and, as recipe memorizers, have no way to evaluate the mixology in Thomas’ book.
To be fair to Jerry, it should be pointed out that using plenty of ice to either stir or shake a drink with was still very new practice in 1862. Deep intimacy with the different results between stirring and shaking had probably not developed yet. The clash of techniques between stirring and shaking true cocktails wasn’t actually settled until… it’s still not settled.