There’s a lot of debate on the story behind this drink’s name: who it could be, what it could mean, and so on. The most likely story is that it wasn’t named for anyone or anything, but was just a combo of the “jack” in applejack and the rose color.
The grenadine isn’t just for color; the tart, fruity flavor of real pomegranate grenadine brings out the rich apple notes in the spirit. You can also use pomegranate molasses if that’s what’s locally available; you might need to add a touch of simple syrup if yours isn’t sweet enough.
Shake with ice and strain into a chilled cocktail or coupé glass and garnish with a lemon twist.