While you might love avocados year-round, imports of this creamy green fruit increase by as much as 40 percent in January and early February, according to one industry report, likely because of all that delicious game-day guacamole. There’s nothing wrong with loading up on avocado, which packs fiber and potassium, and is a plant-based source of healthy fats, per the United States Department of Agriculture (USDA), but when it comes to the proper way to store cut avocado, things have been known to get a bit dicey.
Cut avocados tend to brown easily, and while there are plenty of hacks that claim to prevent that process and keep avocados fresh for a month, not all are safe. Following the wrong advice could even lead to foodborne illness. In 2022, the U.S. Food and Drug Administration (FDA) issued a warning in response to a viral social media trend that suggested storing whole or cut avocados in water keeps them fresh for longer — the videos continue to rack up views.
In one, which got more than four and a half million views, the TikTok user @sidneyraz stored half an avocado in a container of water overnight, taking it out the next day to find it was still ripe and green. Another user, @shamamamahealing, stored an uncut avocado in a jar of water in the fridge, revealing perfectly smooth, green fruit on the inside after a two-week soak. Her video quickly went viral, amassing more than six million views before she took it down, Newsweek reported.
The idea sounds plausible. Avocados start to turn brown when they’re exposed to oxygen, in a process called oxidation, says Matt Regusci, the principal compliance officer at New Era Partners, a company that specializes in food safety compliance. “The same thing happens with apples and potatoes,” he explains. “There is nothing wrong with the browning as far as a health risk is concerned, it just doesn’t look good.”
By storing the avocados in water, users suggest, you’re slowing down the oxidation process and keeping the fruit ripe and green for longer. But according to the FDA, this practice could have serious health effects. As @sidneyraz exclaimed in a later video retracting his advice (which received just shy of 750,000 views): “Take the avocados out of the water!”
What Are the Health Risks of Storing Cut Avocados in Water?
While water may preserve an avocado’s freshness and flavor for a time, it can also expose you to foodborne illnesses. “The main concern is the possibility that any residual human pathogens (such as Listeria monocytogenes and salmonella) that may be residing on the avocado’s surface may multiply during the storage when submerged in water,” notes Janell Goodwin, a spokesperson for the FDA.
Past research by the FDA showed that 17 percent of imported and domestic avocados had traces of Listeria monocytogenes on their skins, and 1 percent tested positive for salmonella. According to the USDA, Listeria monocytogenes can cause fever, muscle aches, nausea, and diarrhea; salmonella can cause fever, diarrhea, and abdominal cramps. Both can cause severe illness and death in people with weakened immune systems, while Listeria monocytogenes can be particularly dangerous for pregnant women, newborns, and older adults.
“Bacteria like listeria and salmonella are living creatures. They need the right temperature, food, and most importantly water to grow,” says Regusci. “When you cut into an avocado, split it in half, then submerge it in water, you provide the perfect environment to create a pathogenic soup.”
If you choose not to cut your avocados before submerging them, you could still be at risk. Even whole, washed avocados can contain traces of bacteria that leach into the edible part of the fruit over time.
“[Past] research performed by FDA scientists has shown that Listeria monocytogenes has the potential to infiltrate and internalize into the pulp of avocados when submerged in refrigerated dump tanks within 15 days during refrigerated storage,” says Goodwin. “In this case, even disinfecting the avocado skin prior to slicing would not remove the contamination.”
How Can You Safely Keep Avocados Fresh?
Avocados should be stored on the counter as soon as you buy them; once they’re ripe, you can put them in the fridge to extend their life a day or two, according to the Cleveland Clinic. The FDA recommends rinsing whole avocados under running water and scrubbing them with a firm produce brush to remove any dirt or bacteria, then drying them off with a clean towel and storing them at room temperature until ripe.
Once you’ve cut your avocado open, add a squeeze of lemon or lime juice to the exposed surface if you’re not planning to use the whole fruit right away. This will help to keep them fresh for longer, as the citric acid in these fruits can slow down the oxidation process, Regusci says. Then, wrap the fruit in plastic wrap until you’re ready to finish it.
Storing avocado in the freezer is another way to prevent bacterial growth (one avocado freezing video on TikTok, posted by @livecomposed, got almost 11 million views), Yahoo reported. Freezing food to 0 degrees Fahrenheit will deactivate any bacteria present in food, notes the USDA (but keep in mind that these bacteria can continue to multiply as usual once the food thaws). While the video shows whole frozen avocados, cutting them before freezing can be convenient and a way to maintain portion control.
“Quarter the avocados, take the skin off, and throw them in a [resealable plastic] bag. Add a little lemon or lime juice and put it in the freezer,” advises Regusci. (Keep in mind that ice crystals can change the texture of your avocados slightly, so this hack is best for avocados you’re planning to use in smoothies, mousses, or other blender recipes.)
Citrus juice can also keep your bowl of guacamole from browning by preventing oxidation, per a past study, which found that onions have a similar effect. If you have leftover guacamole, drizzle some lime juice on top, then lay plastic wrap directly on top of the guacamole (rather than stretched taut across the top of the bowl). “You want the least amount of product exposed to the air,” Regusci says.
You can also store guac in gallon-size bags in the freezer. “If you push the guacamole flat in the bag, the product will be exposed to the least amount of air and can lie flat nicely in the freezer for better storage,” says Regusci.
While there are any number of creative ways to enjoy avocados, the struggle to keep them from browning is real. Although it is not unsafe to eat a brown avocado or guacamole that’s gotten darker after exposure to air, it’s far from appealing. Storing avocados in water is not a good idea, as it increases the risk of pathogens like listeria and salmonella that can cause foodborne illnesses. Fortunately, you now know several safe, expert-approved options for storing avocados for maximum enjoyment.