Thank goodness you are not here for professional photography. This is my kitchen. It has dark countertops, great lighting for cooking, but poor lighting for photography, and it is usually a bit messy, because we cook at home the vast majority of the time.

Today is Taco Tuesday. Having a theme for different days has made menu planning much easier. Besides Taco Tuesday, we have vegetable stir-fry Wednesdays and fish Fridays.

Taco Tuesday does not always involve tacos. Sometimes there are “healthy” nachos, taco salad, fajitas, barbacoa burritos … you get the picture … things that require guacamole!

The thing that breaks my heart about guacamole is the tiny piece of plastic wrap that goes over the top to keep it from turning ugly. I believe guacamole is still edible when it is grayish brown, but being a food princess, I cannot tell you for sure. I’ll work on getting over the “ew” reaction and get back to you.

Today, I decided to put an end to the plastic wrap by first understanding what is causing the guacamole to turn.

Why does guacamole turn grayish brown?

In short, the same thing that causes metal to brown and rust causes guacamole to turn grayish brown, oxidation. If you wish to nerd out on the chemistry, you’ll want to read “The Chemistry of Avocados” by Compound Interest.

The secret to keeping guacamole green without using plastic wrap

The secret to keeping guacamole green turned out to be considerably easier than I expected.

  1. Select a sealable container that is the appropriate size for the amount of guacamole you are making.
  2. Use plenty of lime juice
  3. Only make enough for one day

A properly sized sealable container will be large enough to hold all the guacamole you made, but small enough to minimize the amount of air able to contact the surface of your guacamole, minimizing oxidation. A taller thinner container would be ideal, as it would limit the air surface more than a wider container. Additionally, if you are a real guacamole diehard, you may wish to invest in vacuum sealable containers, which allows you to suck the air out, similar to the special cork tops for wine bottles, only considerably more expensive.

No matter how great the sealable container is, there is going to be some air that reaches the guacamole. This is where the lime comes in. Lime (and lemon juice) inhibit the polyphenol oxidase enzyme, reducing oxidation further. As you can see, it all comes down to science. It pays to pay attention in chemistry class, kids.

No matter what you do, if you make too much guacamole and try to keep it for more than a couple of days, it is going to oxidize. Try to make it the same day you plan to use it and use it all up.

How to make delicious guacamole

It would be terrible if you read all this way and didn’t at least walk away with a guacamole recipe, so here is my favorite.


  • 2 Hass avocados (They are tastier due to a higher oil/fat content.)
  • 1/2 red onion, finely diced (optional)
  • 1/4 cup Fresh cilantro
  • 1 Lime, cut into quarters
  • Salt to taste
  • 5 cherry tomatoes, finely diced (optional)
  • 1 pickled jalapeños, finely diced (optional)


You will want to start with a bigger sized bowl, rather than making the guacamole in its final storage container, because the bigger bowl minimizes the amount of guacamole ending up on the counter top instead of joyfully arriving into your belly.

  1. Using a fork or an avocado masher, mash the avocados until smooth.
  2. Squeeze the lime quarters onto the mashed avocado and stir well.
  3. Throw everything else into the bowl and mix well.
  4. Transfer to a covered storage container that fits the guacamole mixture snuggly and remember to move any leftovers to a smaller, more appropriate container to keep leftovers greener longer.

Comment below. What is your favorite guacamole recipe? What tricks do you use to prevent guacamole from browning?