An avocado will normally ripen within one to three days on its own, if placed in a paper bag at room temperature. However, if you can't wait that long, there is a faster way to simulate ripening. Microwaving an avocado will render it soft enough to eat or use in recipes. Ripening avocados quickly in a microwave should be done only as a last resort. The fruit will be edible, but the taste will not be as strong as naturally ripened fruit.
Prick the avocado several times with a fork on all sides of the fruit.
Line a microwave safe plate with paper towels and place the avocado on top. If paper towels are not available, you can use paper or cloth napkins or an old paper bag to line the plate.
Place the entire dish in the microwave and set the power to medium. Cook for 30 seconds, and then stop the microwave to check the avocado. If it still isn't soft enough to eat, place it back inside.
Microwave for another 30 seconds, and then check the fruit again. Continue microwaving in increments of 30 seconds until the avocado is soft enough to be edible.
Remove the softened avocado from the microwave and use as you normally would. Ripening in this manner is great for guacamole or any other recipe where the fruit requires processing. However, the taste may be a little bland if you plan to eat the avocado alone.
Be careful removing the plate from the microwave. If you have to heat the avocado for more than 60 seconds, it could become very hot.