by Gary Mount
Many fruit and vegetable crops are extremely perishable. Farmers must pick them and then sell them in a short time period. Take leaf lettuce, for example. Weâ€™ve been growing some great leaf lettuce this yearâ€“everyone loves it. But, if it is not sold within a day or two of harvest, forget it. Refrigeration helps, but only slightly. The same is true of many of the crops we growâ€“except for apples. The potential to store apples for many months with no loss of flavor or quality puts them in an entirely different category. Partly because of their year â€™round availability, apples have become the number one produce item in the US.
Storing apples has not always been so successful or well understood. In colonial times, before refrigeration and before any understanding of disease and insect pests, apples did not keep very long. Some even went bad on the tree before they were picked.Â But actually most apples grown in those times were not destined to be eaten. They were made into ciderâ€“which at that time meant alcoholic cider. The apples were stored in a liquid state. Most farmers had a few apple trees and if the farmer was unable to make the cider himself, he took the apples to a neighbor who could and brought the cider home in a barrel. After the cider fermented, the alcohol acted as a preservativeâ€“the minimum alcohol content to do the job was about 8 percent.
Hard cider was the nationâ€™s favorite beverage until the late 1800s, when it was eclipsed by beer, but despite its popularity, apples were also eaten as well as used in cooking. At that time, apples were stored in root cellars, which were constructed into the slope of a hill next to the farmhouse. The constant, cool temperature and high humidity maintained the apples until winter. The root cellar also kept the apples from freezing, which would accelerate spoilage.
As some farmers started to specialize in producing apples for sale, they had to find better storage methods. When I started in business 31 years ago at Terhune Orchards, apple storage was well understoodâ€“but it was not the same for everybody. I got to know an older apple grower named Ralph DelSanti. Ralph farmed in one of the northern counties, Morris County, I think, and he told me of his â€œstorage method.â€ Ralph had a very large spreading tree near his farm buildings. In the fall he stacked his baskets of apples under the tree and that was it. He did this mostly with varieties that were harvested late in the fall when the weather started to turn cool, especially in the northern part of the state. The tree protected the apples from direct sun and sheltered them from frost, both of which would spoil the apples. Ralph told me that the apples â€œkept pretty good.â€ I was not totally convinced but it took Ralph a month or so to sell all his apples and it worked for him!
The next big advance in apple storage was mechanical refrigeration. We take it for granted now, with our refrigerators, freezers and air conditioning, but as the refrigeration industry grew in the early to the mid 1900s, it was a welcome innovation to the apple growers. The technology of apple storage developed rapidly. It was learned what temperatures were best for specific varieties of apples. For example, Red Delicious or Stayman store best at 30-31Â°, but McIntosh stores better at 33Â°. Farmers also learned that refrigeration equipment of adequate size was important. Apples keep better if cooled to storage temperature within 24 hours after picking. Too small a unit takes too long and also condenses so much moisture out of the air in the cold storage that some apples shrivel.Â When it comes to apple refrigeration equipment, bigger is better.
The latest step in apple storing is controlled atmosphere or CA storage. Fruit ripening is partially an oxidation process. By storing apples at low temperature and at a low oxygen concentration, storage time can be greatly increased. Early researchers stored apples at 5% oxygen (compared to the 20% oxygen in the air that we breathe). The latest technology uses 1% or 2% oxygen, and apples can be stored 12 months or more. In fact, scientists at Cornell University are said to have stored apples successfully for up to four years. I am not sure what â€œsuccessfullyâ€ means, but thatâ€™s impressive.
Those of you readers who know me have an idea of what I am working towards.Â It is sort of like tractorsâ€“never having enough. The fact is, we need a new cold storage. Many of our apples now are trucked to southern New Jersey to be stored in a friendâ€™s cold storage. I have dreamt of building a cold storage for several years, and during a trip to Nova Scotia last winter, I visited two farms that had just the type of cold storage I want. Maybe next year, visitors to Terhune Orchards will see new constructionâ€“a modern apple cold storage.