This is an early (pre-Civil War) drink used by farm workers in the field. Vinegar helps to keep potassium levels up, the honey soothes the throat during a hard day of haymaking, and the ginger helps with digestion and absorbing the potassium. Also called haymaker's punch. It is very tart, probably takes a bit of getting used to.
One to two tablespoons of ground ginger can be used here. I like a lot of ginger, so many folks may wish to use less.