Is It Safe To Eat Brown Guacamole?

Is there any chip that guacamole can't improve? A mash-up of avocado, onion, and lime juice (among other ingredients), guacamole actually originated with the Aztecs. Whether you buy it pre-made or make it yourself (homemade guacamole is easy with store-bought pico), it's a cool, creamy topping or dip. Put it back in the fridge when you're done with it, though, and you might find the next day that it has turned brown. Is it still safe to eat?

Brown guacamole that is less than three days old and has been consistently refrigerated (meaning it hasn't been left out at room temperature for more than two hours) is still safe to eat — it has simply oxidized. Oxidation occurs when enzymes in the avocado's flesh react with the oxygen in the air (hence the name of the process), changing the color from bright green to a dank brown. It doesn't look the best, but if you give it a stir, the brown stuff on top mixes in with the still-green guac underneath, effectively eliminating it (if making the entire container a bit darker than before). Alternatively, you can just remove the offending layer and eat what's underneath.

Unfortunately, there is no completely stopping the oxidation process, but you can make an effort to mitigate the unsightly browning. The first method involves tearing off a piece of plastic wrap and patting it down on the surface of your guacamole (after you have smoothed it down with the back of a spoon so that there are no bumps). Then you can place the lid on the container as normal, and put it in the fridge. The plastic wrap forms a barrier between the guacamole and the air, preventing oxidation.

The second technique involves smoothing the top of the guacamole in its container and then covering it with a bit of tap water or citrus juice — enough to completely cover the surface in a thin layer. You can then put the lid on it and then stick it in the fridge like usual. When you want to eat more, simply pour off the liquid. With this method, the liquid forms a barrier between the guacamole and the air, just like with the plastic wrap. But, if you use citrus juice, there is an added effect, as citric acid itself disrupts the oxidation reaction.

While a brown top-layer on your guacamole is totally safe, if the dip has been open for more than three days, it might be best to toss it (particularly if more than the top layer has changed color). Guacamole that has gone bad also tends to exhibit separation, so if there's a lot of wetness in the nooks and crannies of it, your best bet is likely to throw it out.

Whether or not the three days have passed, if your guac has an "off" odor – which is basically anything funky or different from how normal, fresh guacamole smells — it's a sign it has started to spoil. And if you see mold or any type of fuzz on the surface of your avocado dip, it should go straight into the trash, no questions asked. Guac: dangerous to make (what with all of the avocado-slicing accidents), and potentially dangerous to eat when it's past its prime.