There’s nothing worse than brown, oxidized avocado. The flavor is off and it looks very unappetizing! Thankfully, using lime juice and pressing the avocado seed into the mashed avocado keeps it fresh and green for up to 4 days. This technique is sometimes known as a myth but I’ve tested it and it works! This isn’t the only method for keeping avocados green. If you’re still worried about browning, press a layer of plastic wrap directly on top of the mash before sealing the container lid on top. You can also pour a thin layer of cold water on top, then drain it before serving the spread.