Dash in cocktails.

 The most accurate measurement of a dash in the industry is "a little less than one milliliter," he relayed.

Measured out in drops, using a precise, milliliter-dropper like the ones used to dispense medicine, a dash is about 10 single drops. Measured out in teaspoons, a dash would be 1/5 teaspoon, or as I discovered in my kitchen, between 1/8th teaspoon and 1/4 teaspoon.

What If Your Dash Is Not Their Dash?

So long as you don't add 20 dashes when only one or two would suffice, you probably won't ruin your drink. "It's a measurement for which it is deemed acceptable to be a little bit casual," Elliot told me. "Dashes are typically small volumes so that even at the peak of inconsistency, their flavors are not so powerful that the difference in the drink is enormous."

If you're not sure if you're adding enough or adding too much bitters to your cocktail, start with a single dash, then taste as you go. "You can always add more, adjust up, but like a haircut, you can't adjust down," said Trevor.