Avocados are a fruit with a growning range from northern Mexico to South America. California is the leading grower of avocados in the United States and produces them year-round. Avocados mature on the tree but will not ripen until picked. In fact, they are sometimes stored on the tree to await favorable market conditions. They are ripened during storage, distribution and often after being purchased by the consumer. If need be, you can ripen avocados overnight.
Choose avocados for immediate use when their flesh is soft enough to give slightly when pressed with a finger or gently squeezed in one hand. For best results, the skin of most avocados should be dark green but not wrinkled. However, some varieties of avocados will remain green, even when ripe. Testing for softness of the avocado is the best indicator of ripeness.
Ripen two or three avocados overnight by placing them in a paper bag or wrapping them with newspaper along with an apple, banana or tomato. Add one piece of fruit for every additional two or three avocados.
Place very firm avocados in a paper bag or newspaper with the apple, banana or tomato near a heating vent or a warmer area of the kitchen. They can also be placed in a warm oven set at 100 degrees.