Originated in the late 1800's but refined at the Rainbow Room in New York City in the 80's (maybe 90's) by Dale Degroff - The King of Cocktails. At first the Whiskey Smash was more of a Mint Julep (if not exactly that...) with just mint, sugar and a spirit of some sort mashed together and served over crushed ice, but Degroff added some muddled lemon wedges to the mix and that is what we now call a Whiskey Smash.
This is a winner for pretty much anyone, and here's how I make mine!
Muddle (SMASH) 1 lemon wedge
Gently Muddle (SMASH...) 8-10 mint leaves
1/2 Demerara Syrup
1/2 Fresh Lemon Juice
Give this a quick shake, serve over crushed ice and garnish with a big mint bouquet.
Here's the recipe for my rich demerara syrup:
2 parts demerara sugar
Heat this mix up in a pan, don't let it boil, just make sure the sugar crystals are fully dissolved. Let it cool, store in a mason jar with a lid for up to 2-3 weeks. You'll know the syrup has gone bad when it gets cloudy.