But there are easier ways to hold onto that green.
If you want to savor your avocados and guacamole without worrying they'll turn an unappealing brown, a new machine called the Natavo Zero—dubbed the "Avocado Time Machine"—is here, from Australia, to help. "It works by using steam to create pressure fluctuations that switch off the enzymes responsible for browning," Fast Co. explains. "And then they stay green, whether you opted to process them into slices, dices, or mush."
Designed to process up to 4,000 avocados an hour, the machine is clearly designed for industry (not home use). But if you're looking for a kitchen countertop-sized solution for browning avocados, there are some easy steps you can take in food prep to help keep your avocados greener, longer.
1. Add lime juice, cover with plastic wrap. Lime juice tastes great in guacamole, and the acid also helps slow the browning process—and plastic wrap helps keep oxygen out.
2. Add water to the top of your guac before storing. For anyone who doesn't want to offset the balance of lime juice in their guacamole recipe, consider adding a thin layer of lukewarm water in your storage container to create an airtight seal before refrigeration.
3. Apply olive oil, then cover with cling film. For leftover avocado slices (or halves), try brushing the exposed green surface with olive oil before covering with cling film or popping it into an airtight container and refrigerating.
4. Freeze them. If you plan on using your avocados later on for smoothies, fries, or guacamole, consider freezing them!