In theory, this hack is supposed to work because the water keeps air from getting to the open fruit. Avocados, like some other fruits (apples come to mind) turn brown because oxygen in the air causes the flesh to oxidize. So in order to keep the fruit green, you need an airtight seal. Since water adheres to the groves and curves of the fruit, it theoretically blocks all air from making contact. Here’s how it went for me: Yesterday morning I sliced open an avocado and stored one half in a small container of water. Today, just about 24 hours later, I examined my avocado experiment. The good news: It was still pretty green! There was a small amount of browning, which I assumed was due to the oxygen exposure it got while I was making breakfast the previous day. The texture of the external part of the green flesh was a bit, for lack of a better word, slimy—but as soon as I sliced it up and mashed it onto a bit of toast, the texture seemed totally normal. All in all, yeah, it works. However, I don’t think I’d leave it for more than a day. And I don’t know if it’s necessarily the best way to store an open avocado. “What I usually do is leave the pit in the unused half and wrap it very tightly,” dietitian Jessica Cording, M.S., R.D., CDN, told mindbodygreen, “to prevent oxygen from interacting with the enzyme in the avocado and turning it brown.” Like me, she finds this strategy keeps the avocado fresh for as long as necessary: “That usually only buys about a day, but it’s not like avocados go very long without being eaten in my home, anyway!” The other method she recommends is brushing some lemon or lime juice on the surface of the avocado, “as the antioxidants in the citrus help slow down that browning process,” says Cording. Once again, this only slows that browning process—it won’t prevent it completely. Looking for other ways to stretch your avocado longevity? There are actually a couple of tricks that may help you find the perfect avocado in the store. And when you do bring them home, only store them on the counter to soften if you want to use them within three days—otherwise, pop them in the fridge and take them out three days before you use them. And believe it or not, you can even freeze avocados to keep them perfectly ripe for months.
