A Close Up on Cranberries

The holiday season brings with it a number of traditions that are celebrated here in the United States, one of the most notable being the annual Thanksgiving feast. A staple food in this scrumptious, overindulgent feast is the Cranberry. Very similar to blueberries, this small fruit is often turned into juice, jam, jelly, or sauce. With an autumn harvest, this traditional meal association brings a period of peak demand for cranberry farmers---and the need to maintain proper storage conditions when shipping these bright red fruits.

Cranberries are a cold weather crop, thriving in states like Wisconsin and Massachusetts, as well as many Canadian provinces. Cranberries grow in bogs and require acidic, wet soil. They also require vast amounts of sunlight. Once planted in these conditions, the maintenance is very little. The most common way to harvest cranberries is to flood the bog. The berries are then stripped from the plants by motorized rotating water reels. Any free-floating berries are removed from the water by conveyor belts.

Once harvested, proper storage becomes a top priority. If the cranberries cannot be gathered and put into the proper storage conditions within a few hours of stripping, then decay and rotting can quickly occur. Early harvested fruits usually have a longer storage potential than late-harvested fruits. Physical damage, which can occur during mechanical or rough hand-harvesting, transport, cleaning, sorting or packing, increases the likelihood of softening and decay along with reducing storage life.

The optimum storage temperature of cranberries is between +2ºC and +4ºC. Fresh Cranberries can be kept 3-5 weeks in a refrigerator cooled to a temperature of 0-7°C (32 – 45°F). When frozen, they can be stored for 10-12 months. It is important to note that Cranberries ripen to a dark red color after several weeks of storage in either temperature. Cranberries stored at 0ºC for longer than about 2 weeks are at risk of chilling damage. The low-temperature breakdown is characterized by a dull external appearance and watery or rubbery flesh of a deep maroon color. Moisture loss is also an important factor to consider when shipping and storing cranberries. Keeping humidity at high levels and maintaining an Oxygen level at 1% or higher is important in order to prevent moisture loss and foul flavoring.

Many people don’t consider the immense care that goes into producing delicious Cranberries. So this year while you are savoring your mashed potatoes and turkey, don’t forget to grab some cranberry sauce and appreciate the effort that went into maintaining proper production and storage conditions from harvest all the way to your Thanksgiving plate.


Happy Thanksgiving from Dickson!