Grate the apple into a bowl. Add the vinegar and honey. Cover and let it sit overnight, as a minimum, or up to two days in the refrigerator. The flavours will become stronger the longer it sits. Try different lengths of time to find what you like the best.
Strain the liquid into a jar — remember to squeeze out all the juice from the pulp — and seal. It will keep in the refrigerator for months.
Apple Whiskey Shrub
1 oz apple shrub (see above recipe)
1 oz whiskey - we used Gilead 66 Crimson Rye
1 oz apple cider
Serve over ice and garnish with a slice of apple or frozen crab apples.