My version of the salty dog is a shorter, boozier take on the classic, served in a rocks glass with a higher ratio of gin to grapefruit. The salt rim brings out the sweetness in the grapefruit and balances the bitterness beautifully. For a longer, more traditional version, see the notes below.
Pour a thin layer of salt onto your small plate. Moisten the rim of each glass with a piece of grapefruit or a damp paper towel, then dip the rim in the salt until it's nicely coated.
Combine the gin, grapefruit juice, and simple syrup with ice in your cocktail shaker. Shake just until chilled.
Fill your salt-rimmed glass with ice, strain the cocktail into the glass, and garnish with a slice of grapefruit and a sprig of rosemary. Enjoy!
Notes
Both US customary and metric measurements are provided.
This is a shorter, boozier version served in a rocks glass. For a longer, more traditional salty dog, increase the grapefruit juice to 4 to 5 oz / 120 to 150 ml and serve in a highball glass.
Fresh squeezed grapefruit is delicious if you've got the time, but bottled works too. Bottled will make the drink sweeter though so you might need to adjust the simple syrup.
Ruby red grapefruit is sweeter and gives the cocktail a beautiful pink color. White or pink grapefruit will be more tart, so you may want to add a little more simple syrup.