While there are many different methods for shelling black walnuts, most people search for a method that will produce nutmeats with as little mess as possible. Because black walnuts contain a black dye that will stain anything it touches (including skin and clothing), you must take care to protect every surface from the dye. Once you harvest your black walnuts from the tree, there are steps you can take to easily shell them.
Put on old clothing to avoid staining your good clothes. Put on gloves to protect your skin from the black dye.
Fill the bucket with black walnuts that you pick from the ground.
Remove the outer hull from the nuts by rolling the nuts on a hard surface with the bottom of your shoe. The pressure as you roll will loosen the hull. Discard the hulls.
Place the hulled nuts back in the bucket and fill the bucket with water. Rinse off the nuts to remove as much of the dye as possible. As you rinse the nuts, discard any nuts that float to the top of the water because they are empty. Drain the bucket of water.
Spread the nuts on a screen (stacking them two or three layers high) and let them dry for two to three weeks in a cool, dry area.
Lay the tarp flat on a concrete surface to protect the concrete from staining.
Place the black walnuts, one at a time, onto the tarp with the point of the nut facing up. Pound each nut with the hammer until it splits in half. Hammer the walnut squarely to split the shell open.
Pull the shell apart to reveal the walnut inside. If the nutmeat is difficult to remove, use a pick to pry it loose.
Place nutmeats into the bowl and discard the shells in the trash bag.
Store the nutmeats in plastic freezer bags. You can store them in the freezer indefinitely, or in the refrigerator for one to two weeks.