Cranberries are a unique fruit native to North America, often grown in specialized beds called bogs. Their harvest process, which takes place annually from mid-September through early November, is unusual because it depends entirely on the final use of the fruit. This process employs two distinct methods—one dry and one wet—that determine whether the berries will be sold fresh or processed into products like juice or sauce. The choice between these two vastly different techniques is made to preserve the berries’ quality and maximize their utility for a specific market.
The Dry Harvesting Method
The dry harvesting method is used exclusively for the relatively small percentage of the crop intended for the fresh fruit market, such as the bags of cranberries sold in grocery stores. The bogs are not flooded for this process, which helps maintain the berries’ quality and ensures a longer shelf life. This technique is designed to be gentle, minimizing the bruising that would quickly degrade the fruit’s appearance and texture.
Specialized self-propelled mechanical pickers are used to comb the berries off the vines. These machines use rotating metal teeth or tines to detach the fruit, which is then conveyed into a receptacle, often a burlap bag or wooden box.
The harvest must be performed while the vines are completely dry, as moisture from rain or heavy dew can delay the operation and cause the delicate fruit to spoil faster. Once the containers are full, they are carefully removed from the bog, sometimes by small bog vehicles or even helicopters, and transported to a receiving station. This gentle, labor-intensive method is necessary because the berries must remain firm and unblemished for consumers purchasing them as whole fruit.
The Wet Harvesting Method
The wet harvesting method accounts for the vast majority—often over 90%—of the annual cranberry crop, destined for processed goods like juices, sauces, and dried cranberries. This visually striking process begins when the bogs are intentionally flooded with up to 18 inches of water, typically the night before the harvest is scheduled to begin. The reason this method works is a fascinating biological fact: each ripe cranberry contains four tiny air pockets within its core, granting it natural buoyancy.
Once the bog is flooded, workers use specialized machines known as water reels, or “eggbeaters,” which are driven through the submerged cranberry patch. These machines have rotating paddles or tines that agitate the water, effectively shaking the ripe cranberries off the vines. The detached berries immediately rise to the surface of the water due to their internal air pockets, creating the famous floating red “carpet” seen in photographs.
The floating berries are then gathered and concentrated into one area of the bog using long, floating barriers called booms. These booms corral the mass of fruit toward a collection point, often at the edge of the field. From there, the berries are either vacuumed directly out of the water or lifted onto waiting trucks via a conveyor belt system. This efficient method allows a crew to harvest an entire bog in a day or two, which is far faster than the dry-picking process.
Post-Harvest Processing Differences
The harvest method dictates the immediate post-harvest processing steps.
Dry-Harvested Processing
Dry-harvested cranberries, meant for the fresh market, are transported to a screening facility for immediate quality control and packing. They undergo a rigorous sorting process where they are inspected for color, size, and firmness. This often involves a bounce test, as a healthy, firm cranberry will bounce higher than a soft or damaged one.
These fresh berries are then quickly packaged in bags or containers and placed in refrigerated storage to maximize their shelf life, which can be several weeks or months. Any delay in this initial sorting and cooling process can compromise the integrity of the fruit intended for fresh use.
Wet-Harvested Processing
In contrast, wet-harvested cranberries have a significantly shorter shelf life due to being submerged in water and the rougher agitation required to remove them from the vine. These berries are transported immediately to a processing plant for cleaning. They are washed, sorted to remove debris, and then rapidly processed into products like juice concentrate or dried fruit. Rapid processing prevents spoilage, as the water exposure accelerates the fruit’s natural degradation.