How to Keep an Avocado from Turning Brown

Avocados are packed with healthy fats and potassium—but who hasn’t put an unused avocado half in the fridge, only to find the fruit turned a totally unappetizing brown the next day? It’s one of the most frustrating things about loading up on avocadoes—here the solution.

Just cut a red onion into fairly large chunks, throw the pieces an airtight container, and place the avocado half—with the pit—on top. (The skin should be touching the onion chunks.) Put the lid on the container, throw it in the fridge, and brown avocadoes will be a thing of past. How does the trick work? The onion emits sulfur gases, which help stop the oxidation process that turns avocadoes brown.