Chill your highball glass or tall tumbler by placing it in the freezer or filling it with ice.

Measure 2 ounces (60 milliliters) of Scotch whisky with a jigger and pour it over the ice in the chilled glass.

Slowly add 4 to 6 ounces (120 to 180 milliliters) of soda water to the glass, adjusting the amount to your taste.

Stir gently with a bar spoon for about 5 seconds to combine and chill without over-diluting.

Cut a 2-inch long, 0.5-inch wide strip of lemon peel and twist it over the drink to release its oils.

Drop the lemon twist into the glass as a garnish and serve immediately while cold and effervescent.