Apple brandy is possibly the best spirit on which to base a sour but this recipe for an Applejack Sour is on the tart side. If acidic cocktails are not...
I distinguish between calavdos, which is traditionally 40% alc./vol., and applejack, which is properly 50 alc./vol. (bottled in bond). This recipe is designed for applejack, so if using calvados, you’ll need to increase the volume by 25% to 56ml.