In the same way sun exposure ages our skin, oxygen is the enemy of fruit that doesn't want to brown.
Avocados and other fruits have an enzyme called polyphenol oxidase. When it consorts with oxygen, brown pigments form in the green flesh. That’s why when you leave out freshly made guacamole or a cut-up avocado, it turns brown quickly. But packaged guacamole always seems to be bright green upon purchase, despite having sat on the shelf for countless days. What's up with that?
Manufacturers have to make sure there’s no oxygen present in their packaging if they want the product to stay green, says Ardy Haerizadeh, the CEO of guacamole manufacturer Yucatan Foods. They can do this by vacuuming the oxygen from packages, having plastic film in contact with the top of the guacamole, or filling the headspace of tubs with nitrogen gas.
The enzyme is also sensitive to temperature and acid, so manufacturers can maintain the green color of their guacamole by refrigerating the product and by adding citric acid and/or ascorbic acid, says Diane M. Barrett, director of the Center for Fruit & Vegetable Quality at the University of California–Davis. Acids lower the pH “to the point that the enzyme is not that active,” explains Barrett, who adds that enzymes are also “less active at cold temperatures.”
Refrigeration, adding lemon or lime juice, and limiting exposure to oxygen can also help keep homemade guacamole from turning brown. Chowhounds offer a helpful guacamole timetable for a seven-layer dip.
On a related note, if you do buy commercially prepared guacamole, read the ingredients carefully. Haerizadeh says the FDA hasn’t created a standard of identity for the dish, so manufacturers can label pretty much anything they want as guacamole, whether it’s 95 percent avocado, or a “guacamole flavor” dip that contains less than 2 percent avocado.
You know what's great to wash down all that guacamole? Something a little sour, a little sweet, and a little salty, like this margarita recipe from liquor.com.
As long as you have a ripe (slightly soft to the touch, and if it's a Haas avocado, black on the outside) avocado, guacamole is simple to make yourself. Try some of our recipes, from classic to quite alternative.
Homemade avocado is as easy as chopping and peeling a few ingredients and then mashing it all up. Here, you'll need a tomato, lime juice, chiles, cilantro, scallions, and salt — in addition to the avocados, of course. Get our Guacamole recipe.
2. Guacamole Taquero (Tomatillo Guacamole)
This tart-tasting blended version is a mix of avocado, tomatillos, epazote (or you can use cilantro), chiles, garlic, onion, and lime juice. Get our Guacamole Taquero recipe.
3. Bacon and Tomato Guacamole
The only other ingredient that could possibly make guacamole more decadent than it already is with all that creamy goodness, is bacon. Yeah, there's tomato in there too, and that's nice. Get our Bacon and Tomato Guacamole recipe.
4. Dungeness Crab Guacamole with Endive
Garlic is roasted until it's sweet and jalapeños are all blistery-good in this recipe that's quite an indulgent appetizer when you're entertaining guests. Two of everyone’s favorite flavors — crab and guac — combine for a terrific start to a special meal. Get our Dungeness Crab Guacamole with Endive recipe.
5. Pineapple and Cucumber Guacamole
On the other end of the guac spectrum, there's this sweet, fresh, creamy, and acidic version. Diced instead of smashed or blended, it's more salsa-like than the others. Get our Pineapple and Cucumber Guacamole recipe.
6. Toasted Almond Guacamole with Apricots
Now here's a guacamole with not one, but two unexpected twists. Celebrated Chef Rick Bayless came up with this nutty, sweet incarnation. Get our Toasted Almond Guacamole with Apricots recipe.
— Original article by Roxanne Webber on May 8, 2009; updated article by Amy Sowder on Sept. 17, 2016.
— Head photo: Avocado.com.