Watch any classic film with a bar scene and you're sure to hear one of the smooth players of old Hollywood order a finger of scotch, an imperfect measurement system with Old West roots. Since the number of liquid ounces poured varied with the width of the bartender's fingers, the terminology faded from use. However, it is making a comeback with bartenders attempting to standardize it by making the "finger pour" equivalent to 3/4 inch per finger, accepting 1 ounce as the standard for a one-finger order, according to Sean Kenyon, a United States Bartenders Guild-certified Spirits Professional, in a 2010 Denver Westward article. This means that if an old soul places a drink order for a finger of Scotch whisky at your next party, you can serve with confidence.
Hold a clear lowball glass in your non-dominant hand. This type of glass goes by several names, including old-fashioned glass, rocks glass and scotch tumbler, and is the common glass used for serving scotch "neat," without ice and "up," with ice.
Hold the tumbler with your index finger wrapped around the base so you can clearly see your finger through the glass. If you were to set the glass on the table, the inside of your finger should rest flat on the table.
Pour room-temperature Scotch up to the height of your finger width, also called "fingerbreadth." Keep in mind that the actual measurement for a 1-ounce pour is 3/4 inch.