One of the most important things you can learn about cocktails is that they have an internal consistency. Ingredients balance each other in fairly predictable proportions, even if they have to be tweaked for the particular character of individual expressions and personal tastes.
That's how, when asked to make a cocktail using St. Germain, I was able to cobble together almost this exact recipe despite the fact that I had never seen it before, with the exception that I used orange instead of peach bitters.
This cocktail comes from a time when St. Germain was the new kid on the block and bartenders were figuring out how to use it. Jaime Boudreau of Canon in Seattle posted a couple of drinks with it, including this one.
1.5 oz gin (1:1 Tanqueray/Beefeater)
0.75 oz sweet vermouth (Punt e Mes)
0.25 oz elderflower liqueur (St. Germain)
2 dashes peach bitters (Bitter Truth)
Combine all ingredients, stir with ice for fifteen seconds, then strain into a chilled coupe and garnish with a strip of lemon peel.
The nose is balanced between the gin and vermouth, brightened by the lemon peel. The sip opens with liqueur and vermouth sweetness, passes through elderflower and citrus notes, then fades into complex bitterness from the vermouth, gin, and bitters.
This kind of drink is how St. Germain acquired the term 'bartender's catsup'. It does exactly what it is supposed to do, providing a subtle twist on an otherwise classic profile and adding a bit of extra body from the sugar. While it's since slipped out of favor from overuse, it's still a great ingredient to slip into your lineup from time to time.
13 hours ago