This past weekend I had a nice dinner of small plates and a couple of delicious cocktails at JP Winebar in the Crossroads. I was happy to get a Manhattan that was not shaken vigorously with ice, but rather gently stirred with a bar spoon. Certainly the shaker is the quintessential sight and sound of the cocktail revolution, but it should only be used when entirely appropriate.
Simpler drinks, particularly true cocktails with only two or three ingredients, should almost always be stirred. I have heard conflicting reports about what shaking actually does to a drink. Certainly shaking makes a drink colder and also gives it a cloudy appearance. Drinks that involve an egg white, fruit juice or any kind of syrup typically benefit from being shaken.
I have also heard that a shaken drink is more alcoholic because the ice fuses with the water content of the alcohol and is strained out prior to serving. My experience is generally that shaking drinks makes them weaker, or at least removes the “bite” from distilled spirits. I can always tell when a Manhattan has been shaken. Also the consensus is that martinis should be stirred but I think the superior coldness outweighs all the other factors for most drinkers. Plus, people expect to see you get out the shaker when they order a martini.
That being said, if you have a preference, by all means express it to your server or bartender. I’ll bet that most bartenders would think it’s cool if you asked for your martini stirred. These people like to make good drinks after all.