I was gifted some White Grapefruit from someone locally who has a neighbor with a tree, so I did some comparison testing with a Rudy Red.
Old Friend
¾ oz Grapefruit Juice
½ oz Campari
¼ oz Elderflower Liqueur
1½ oz Beefeater Gin
Shake with ice and strain into a coupe. Garnish with a lemon twist.
The original spec calls for St. Germain but I only have the Giffard Elderflower.
I made two of these, and found that I preferred the sweeter Red Grapefruit in the cocktail. I don’t know that I would have refused the tarter one with White Grapefruit, but the difference between the two was certainly obvious and noticeable given the relative percentage of juice in this recipe. And you know I like things a little sweeter. Overall, this was a pretty tasty cocktail either way.