There are many theories on how to prevent browning or oxidation, but according to Food52, the best tactics to save an uneaten second half (as if), are to line the bottom of a storage container with chopped red onion (which may give your fruit a slight onion-y flavor), brush it with lemon juice, or simply do nothing besides storing it in an airtight container.

Cooking with avocados often requires advanced planning. It will usually take a few days for a fresh (hard) avocado to ripen. You can speed up the process by placing them in a paper bag on the counter or with another ethylene producing fruit like a banana or apple. A ripe avocado will have a slight give when squeezed.

Avocados start ripening after they are picked. If refrigerated too soon, they’ll remain hard. Best bet is to keep them on your counter until they’re soft and ready to use. Ripe avocados can be kept in your crisper drawer for about a week.