Avocados present a unique challenge for harvesting because, unlike most fruit, they do not ripen while still attached to the tree. Successful avocado enjoyment depends entirely on picking the fruit at the correct stage of physiological maturity and managing the post-harvest process. Picking an avocado too early means it will never develop its desirable creamy texture and flavor. The subsequent handling and storage techniques are essential for ensuring the fruit reaches its peak ripeness.
Identifying When Avocados Are Ready to Harvest
Avocados must reach physiological maturity on the tree before they can ripen once picked. This maturity is often measured scientifically by dry matter (DM) content, which reflects the accumulation of oils and solids in the flesh. For commercial Hass avocados, the industry standard for minimum maturity is often set around 20.8% DM, though this varies by cultivar and region.
Visual cues, such as the fruit losing its glossy shine or a slight change in the stem’s color, offer a general indication. However, these external indicators are unreliable because different varieties mature at different times; ‘Hass’ changes from green to purple-black, while ‘Reed’ remains green. The most reliable home-grower method is the “test harvest,” where a few fruits are picked and allowed to ripen indoors.
If the test fruit softens evenly within a week to ten days without shriveling or tasting watery, the remaining fruit on the tree is ready for harvest. Fruit that fails to ripen properly was picked prematurely, indicating a need to wait longer. Varieties like ‘Hass’ and ‘Fuerte’ have differing seasonal windows. Some avocados can remain on the tree in a mature, unripened state for many months, a process growers call “tree-storage.”
The Proper Technique for Picking Avocados
The physical act of removing the avocado from the tree requires specific tools and a careful technique to maintain fruit quality and shelf life. Using a sharp tool, such as hand clippers or a specialized picking pole for higher fruit, is preferable to pulling the fruit by hand. Pulling can damage the branch and may result in the stem separating improperly.
It is important to leave a small piece of the stem, called the “button,” attached to the avocado when harvesting. This button acts as a natural seal, preventing air exposure to the stem end. If the button is removed, the open attachment point exposes the flesh, allowing mold or rot to enter and drastically shortening the storage life.
The goal is to clip the stem about a half-inch above the fruit, which preserves the protective button. Gentle handling is also necessary during the entire process to prevent bruising, as physical damage affects the quality of the flesh and can accelerate decay. For fruit on tall trees, a clipper pole, which cuts the stem and catches the fruit, is used to ensure the stem end remains intact and the fruit is not bruised by a fall.
Post-Harvest Ripening and Storage
Avocados are climacteric fruit, meaning they produce a burst of the plant hormone ethylene after harvest, which triggers ripening. This process involves the conversion of starches into sugars and the softening of the flesh. The optimal temperature for this transformation is between 60°F and 70°F (15°C to 21°C), away from direct heat or cold.
To accelerate ripening, avocados can be placed in a loosely sealed brown paper bag. The paper bag traps the naturally occurring ethylene gas the fruit emits, concentrating the hormone and speeding up biochemical changes. Adding other high-ethylene-producing fruit, such as a banana or an apple, further increases the gas concentration, which can ripen the avocado within one to three days.
Once the avocado yields slightly to gentle pressure, indicating it is ripe, its metabolism should be slowed to extend usability. A ripe avocado can be stored in the refrigerator for a few days to delay further softening. However, refrigeration can affect the texture, so the fruit should be used shortly after cooling.