There are lots of opinions on what makes a perfect batch of guacamole. Should it be chunky or smooth? Should it have cilantro? How much lime juice, if any, and must it be freshly squeezed? With all the debate, there’s one thing we can surely agree on: Guacamole should never, ever be permitted to turn brown.
Guacamole enthusiasts have devised all kinds of tips and tricks for how to keep avocados from turning brown and many have trickled down to guacamole storage: Leaving the pit in, pressing plastic wrap onto the surface, and adding citrus juice are popular options, but there are plenty of eclectic anti-browning methods espoused on the world wide web. We tried a whole bunch of them to see which actually worked. More on that in a minute, but first:
Why does guacamole turn brown?
When you slice an avocado, the knife damages the plant’s cells, exposing them to oxygen. An enzyme in the avocado called polyphenol oxidase interacts with free-flowing oxygen to cause browning—hence the term “oxidation.” The same chemical reaction is responsible for the browning of potatoes, apples, and bananas.
Browned guacamole is completely safe to eat, but not the most…appetizing. So several Epi contributors ran tests to see which trick kept guacamole bright and green the longest. Video producer Tommy Werner made eight samples and one control from a single batch of our highest-rated guacamole recipe. After an overnight rest in the Epi Test Kitchen fridge, none of the samples showed signs of browning. Takeaway #1: Keeping guacamole cold keeps it green.
To take the testing a step further, Tommy let the various bowls of guacamole sit at room temperature for several hours to simulate what might happen at a party. Some methods resulted in total failure, rendering unappealing grayish-brown glop. Others managed to keep the smashed avocado as green as green gets. Below, a list of the winning and losing methods:
7 Ways to Prevent Browning Guacamole:
The best way to stop your guacamole from browning is to prevent it from interacting with the air. Now comes the question: What’s the best way to limit the avocado’s exposure to oxygen?
If you’re storing a cut avocado—to be mashed into guacamole, fanned on avocado toast, or used in another avocado recipe—Epi contributor Jess Eng recommends a simple preservation tactic: “Splash some lemon or lime juice (or a sprinkle of citric acid) over the fruit and wrap it tightly in plastic or a designated avocado hugger before placing it in the fridge.” But would the same method work for a bowl of guacamole?
The methods tested below all relied on ingredients or equipment you’re likely to have in your home already. If leftover guacamole is a constant in your life, you may want to invest in a dedicated guacamole saver, like the Guac-Lock.
The Guacamole Trials:
Trial 1. Leave in the pit.
Many people insist that sticking an avocado pit into a bowl of guacamole will keep the guacamole fresh. Tommy found the opposite to be true. After being left on a counter in the test kitchen for an entire workday, “the trial with an avocado pit in the center showed a lot of browning.” He reports that “entire sections were brown, even more than in the control trial.” In short, this method is...the pits. Score: F
