Line the garbage can with both of the oversized trash bags and pull the excess bag length around the outsides of the can. The second trash bag and extra slack will help prevent tearing and leakage.
Load clean, destemmed grapes into the lined garbage can until it is approximately a third full.
Cover your hands with the thick leather gloves and lift the fence post over the can of grapes.
Repeatedly drop the fence post onto the grape pile by lifting the end 12 to 16 inches above the pile and releasing. Guide the post with your glove covered hands as it falls to crush the grapes.
Grab the handles of the garbage can and shake it vigorously before lifting the post to finish the grape crushing.