Making bitters is akin to alchemy, the cocktail equivalent of brewing a magic potion. It begins with the namesake ingredient, a root or bark so bitter as to be unpalatable – cinchona (the source of antimalarial quinine) or gentian (some varieties of which are poisonous) or calamus. Next come the aromatic spices, like cinnamon, clove, coriander, black pepper. Citrus is also prominent, typically as zest or dried peel from lemon, orange, or grapefruit. Finally, herbs for finishing: perhaps rosemary, or a bay leaf. The components are steeped in alcohol, then again in water, to extract the flavors. Strain, add a bit of sweetener, and voila!

And, like a potion, bitters can transform a cocktail into something magical. A classic cocktail like the Old-Fashioned is little more than bourbon or rye, a touch of sugar, and a healthy dose of bitters. But the end result is dramatically different from that same whiskey served neat or on the rocks. Bitters can bind together the sometimes-conflicting elements of a cocktail, or draw out specific flavor notes from the base spirit. They are the bartender’s best friend and secret ingredient. While bitters can’t make a bad cocktail good, they can make a good cocktail sublime.

But don’t take my word for it. I’m a scientist by training, so I propose a simple experiment (let’s call it the Manhattan Project). Prepare the drink without the bitters and take a sip. Now, add a few dashes of bitters, stir, and taste. The difference is dramatic, I assure you.

The Manhattan

• 2 oz. whiskey (I prefer High West Double Rye)

• 1 oz. sweet vermouth (Carpano Antica is my go-to here)

• 2 dashes aromatic bitters (the classic choice is Angostura)

• cherry, for garnish (Fabbri’s Amarena or Luxardo’s Maraschino)*

• cocktail shaker, ice, bar spoon, martini glass or coupe

*Under no circumstances should you use those chemically treated, neon-red abominations that some call maraschino cherries.

Steps

• Half-fill the shaker with ice.

• Add liquid ingredients and stir until chilled.

• Strain into a cold glass (I chill mine in the freezer).

• Garnish with a cherry and enjoy.

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