Pecans that have not fully ripened can be removed from their green outer shell in just a few seconds. Pecans that fall from the tree early in the harvest season are not developed and have a moist bitter nut inside. The green outer husk will dry and split away from the nutshell as the nut matures later in the fall. Peel the green outer shell from pecans that fall from the tree and are not quite ready to eat.
Protect your hands with a pair of thick leather work gloves to keep them from contacting the green outer shells of the pecans. Touching the green shells with bare skin will dye the skin black for a couple days.
Hold a green pecan firmly in your non-dominant hand and press the blade of the knife into the shell until you contact the hard inner shell. The green husk is approximately a 1/4 inch thick.
Score the green shell by spinning the pecan with your hand as you hold the blade of the knife in place. Complete two full circles with perpendicular intersections around the green shell.
Lift the edge of each divided segment with the tip of the blade and peel the green husk away from the hard inner shell.
Scrape away any green vegetative matter that clings to the hard woody pecan shell.