Pre-sizing and Packing | WSU Tree Fruit | Washington State University Skip to main content Skip to navigation

Pre-sizing and Packing

View Print Version

Tree fruit is harvested, placed undercover or in the shade, and then transported to packinghouses as soon as possible after harvest. Apples and pears are cooled as soon as they reach the warehouse to remove the field heat, and cherries are often hydro-cooled in the field before transport, because they start to lose quality as soon as they are picked, and heat exacerbates this. Fruit are sampled, washed, sorted, graded, packed, and stored after arriving at the packinghouse. The variety of fruit, time of harvest, and fruit quality determine the packing and storage protocols that will be used.

Apples are checked for fruit quality when they arrive at the packinghouse, then possibly drenched with fungicides, depending on whether they are Organic or Conventional, and placed in cold storage. Apples are then packed with the Direct Pack or Presize systems. See the apple section below for apple packing steps.

Pears are packed right after harvest, or stored in controlled atmosphere (CA) storage. Pears require “conditioning” in cold storage for a certain length of time in order to ripen properly when consumers purchase them. They are not presized due to their delicate skin, and will not tolerate the extra handling. See the pear section below to learn more.

Sweet Cherries arrive at the packinghouse, and are placed in cold storage immediately. Cherries are then sorted, sized, and packed in a short amount of time due to their shorter storage and shelf life. They can be in cold storage for a couple of months, but are sold as soon as possible after harvest. See the cherry section below for more information on packing cherries.

Apple
Pear

Pears are either packed right after harvest, or are stored in Controlled Atmosphere (CA) storage. Pears are mature, but not yet ripe when harvested, and must undergo a ripening process called conditioning before they are packed so that they will ripen properly when consumers buy them.  Pears are not pre-sized prior to packing due to their thin, delicate skin that bruises easily. At the time of packing, fruit are gently dumped out of bins onto the packing line. Fruit are rinsed, washed with food-grade detergent, and rinsed again. Next, they are run over a bed of brushes and fans, to dry completely. Trained personnel hand sort the fruit, removing any defective or decayed fruit from the line.  Pears can also be sized and sorted with computer technology. Labels are placed on the fruit, indicating the grade, variety, and size, and then they are packed into boxes. This is done by hand and with automation.  Boxes are palletized and put back into cold rooms where they wait for shipment.

Related Links

Pear Handling Manual, An excellent resource from the Pear Bureau Northwest.  (Accessed: 1/19/17).

Cherry

Cherries do not contain stored carbohydrates like apples and pears, therefore have a shorter storage and shelf life, but good fruit quality can be maintained in cold storage for a couple of months. Cherries are difficult to handle because they are very susceptible to bruising (pitting), and extra care is taken on the packing line to eliminate mechanical injuries. Packers refer to a “cold-chain,” which signifies keeping cherries cool during the whole process chain (harvest through the packing process, shipping, retail markets, and until they are consumed.) To start the packing process, cherries float onto the packing line on flumes of water, which protect them from bruising and damage.  Orchard debris and leaves are removed from the flumes with nets. The cherries go through a cluster cutter to cut stems of clusters into single fruit with shorter stems.  Fruit is sorted and sized, either manually by trained personnel, or electronically, with a computer.  With the computer sorter, multiple images of each cherry are taken, analyzed, and fruit are automatically sorted and sized. Fruit that were singled out are sorted again by hand for culls.  Some operations hydro-cool fruit before packing to maintain fruit quality. Cherries are packed into a variety of boxes, clamshells, and bags by size and weight. Cartons are then labeled, palletized, shrink-wrapped and sent to cold storage or refrigerated trucks for shipping.

Washington State University