According to Epicurious, five tested and proven methods help keep your guacamole fresh.  ●      First, you can seal it firmly with plastic wrap. ●      The second method is to add in a lot of extra lime juice before sealing it tightly with saran wrap. ●      The third way to keep it fresh is to sprinkle lime juice over the top of the guacamole, put the pit of the avocado into the center of the guacamole, and then seal it with plastic wrap. ●      Tip number four is to press olive oil onto the top of the plastic wrap and then firmly seal the plastic wrap over the guacamole. ●      The last tip is to sprinkle a little water over the guacamole’s top after patting it down. Firmly seal the plastic wrap over it; you will have fresh green guacamole, not brown!