Not every recipe calls for the whole avocado. So how do I keep my unused avocado half as green as possible until the next meal? Just recently, I found out how to slow down the browning process. I tried it and it works!
The magic works best for when you leave the pit in the avocado, and put the halves in an airtight container before storing them in the refrigerator. According to food52.com, the pit blocks the air from reaching the surrounding layer of flesh. Follow these instructions for each technique to reduce browning.
Brush or squeeze fresh lemon juice on the avocado flesh. The citric acid from the juice does the trick.
Onions also work well. Chop a hand full of onions. Layer the bottom of the container with the onions, place the avocado half on top and seal the container. Thekitchn.com says it is likely due to the vapors that the onions emit, which keep the avocado fresh for a couple more days.
Olive oil, who would have thought! Brush the oil on the halves. The oil will seal the avocado from air, preventing oxidization.
The avocado halves will brown in some degree, but these techniques will keep them green longer.