This is a play on the fresh lime gimlet. I used Ruby Red Grapefruit Juice without HFCS. I augmented the juice by adding 1.284 grams citric acid and .321 grams malic acid to 30ml juice then poured what was needed. I wanted a grapefruit drink that was tart, but without other citrus in it.
21ml Grapefruit Juice +
20ml Simple Syrup
2 Dashes Grapefruit Bitters
Pinch of salt
Shake all with 120g ice for about 20s. Aiming for a total volume of 153ml after straining into a coupe.