Avocados possess a unique physiological characteristic that dictates their entire journey from tree to table. Unlike most fruits that soften and sweeten while still attached to the plant, avocados are a climacteric fruit. This means they mature on the tree but only begin the ripening process after they are picked. This fundamental distinction means the fruit must be harvested hard and green. Growers must precisely determine the moment of maturity to ensure the fruit will ripen correctly for the consumer. This careful manual picking process enables the fruit to be successfully shipped and sold worldwide.
Determining Harvest Readiness
The primary difficulty in harvesting avocados is that the fruit provides few visual cues to indicate it is ready to be picked, as it does not change color or soften while on the branch. Growers must rely on timing and scientific metrics to ensure the fruit has accumulated enough oils to develop its characteristic creamy texture and flavor after harvest. The definitive metric used across the industry is the fruit’s dry matter content, which is closely correlated with its oil content.
Minimum dry matter percentages are legally mandated in many regions to prevent the picking of immature fruit, which would shrivel and taste watery or grassy when ripened. For the common Hass variety, this minimum is often set around 20.8% to 23% dry matter. Growers sample fruit from the orchard and dry the flesh to calculate the percentage of non-water content. More modern methods utilize non-destructive near-infrared (NIR) spectroscopy devices, which can instantly assess dry matter in the field.
Growers also use calendar dates as a guideline, tracking the number of days since the tree flowered to predict maturity. Additionally, a minimum size requirement is often imposed to ensure a marketable product. Pickers use sizing rings or visual estimation to select fruit that meets the commercial standard. These pre-harvest tests are crucial for guaranteeing the physiological maturity required for a proper, high-quality ripening experience.
The Manual Picking Process
Avocados are highly susceptible to damage from impact and abrasion, making the harvest process a delicate operation that necessitates manual labor. Workers use specialized tools to reach fruit high up in the dense canopy of the trees. These tools include long picking poles, sometimes fitted with a basket and a cutting blade or hook, to safely detach and catch the fruit.
For fruit within arm’s reach or on lower branches, workers use specialized hand clippers, often called nippers, to cut the stem cleanly. A crucial technique is to leave a small piece of the stem, known as the “button,” attached to the fruit. This button acts as a natural seal, which significantly reduces the risk of stem-end rot and moisture loss, preserving the fruit’s integrity during transit and storage.
The harvested fruit is never pulled or snapped off the branch, as this tears the skin and creates a direct entry point for pathogens. After clipping, workers carefully place the avocados into padded picking bags or buckets worn with a harness to avoid bruising. These bags are then gently emptied into large field bins, often lined with a soft base, before transport to the packing house.
Post-Harvest Handling and Preparation for Market
Once the fruit arrives at the packing facility, the post-harvest process focuses on cleaning, sorting, and rapidly cooling the avocados to halt the initial stages of metabolism. The fruit is first washed to remove any field dirt, debris, or residues, often in a water bath containing a mild sanitizer solution to reduce surface microbes. This cleaning process may involve soft, rotating brushes, but minimal contact is preferred to avoid damaging the skin’s lenticels.
The avocados then move through a mechanical sorting and grading line where they are separated by size, weight, and quality. Automated systems and human inspectors work to remove any fruit with visible defects, cuts, or blemishes to ensure only premium produce is packed for shipment. The fruit is then packed into shipping cartons, which typically contain data on the net weight, quality level, and country of origin.
The most important step for preserving freshness is pre-cooling, where the fruit’s internal temperature is quickly lowered to an optimal storage range, often between 3.3°C and 7°C. This cold chain step slows the fruit’s respiration rate, delaying the onset of ripening. Avocados are stored and shipped hard and unripe, ready to be treated with ethylene gas later in the distribution chain or left to ripen naturally.