Keeping an avocado fresh for a few days without refrigeration can be a bit challenging, but there are some methods you can try to slow down the ripening process and extend its shelf life:
Store in a cool, dark place: Find a cool and dark spot in your kitchen or pantry, away from direct sunlight and heat sources. This can help delay the ripening process.
Keep it whole: Avoid cutting the avocado until you're ready to eat it. Once the fruit is cut, it starts to oxidize and deteriorate quickly.
Use lemon or lime juice: Citrus juice contains natural antioxidants, which can slow down browning and preserve the avocado's freshness. Rub a little lemon or lime juice on the exposed flesh of the avocado, cover it with plastic wrap, and store it in an airtight container.
Use onion: Some people believe that storing avocados with a cut onion can help slow down ripening. The idea is that the sulfur compounds released by the onion can prevent the avocado from browning. Wrap the cut avocado tightly in plastic wrap and store it with a piece of cut onion in an airtight container.
Submerge in water: Completely submerging the avocado in water can also help slow down oxidation. Place the whole avocado in a bowl of water and store it in a cool place.
Please note that these methods may not keep the avocado fresh for as long as refrigeration would, but they can help extend its shelf life for a few extra days. If you have the option, refrigerating the avocado is still the best way to maximize its freshness and shelf life.