Even the most conservative estimates suggest that approximately thirty percent of marketable vegetable produce is lost each year due to poor handling and storage in the period following harvest. On a global scale this represents a significant quantity of food, enough to support very large populations such as China or India’s. In line with a general emphasis on sustainability, organic vegetable production should be dedicated to minimizing waste and inefficiencies associated with inadequate storage procedures.

Anyone who’s old enough might recall extreme shortages of fresh fruit and vegetables in Britain during the Second World War. Some popular historians attribute this to the breakdown of agriculture caused by labor and equipment shortages. I’ve recently conducted my own research and located material which challenges this viewpoint. During the early years of the war, agricultural production increased marginally in several important sectors. One of these was vegetables. Why then were so many children from London, Manchester, and Glasgow chronically malnourished and scurvy afflicted? It appears one of the most significant factors was a systemic failure to maintain effective distribution and storage for the produce grown in the majority of rural districts.

Local archives of farm records and correspondence frequently reveal the levels of difficulty and frustration experienced by commercial growers. In a letter to his uncle, Douglas Woodbridge of Surrey recorded the loss of his spinach and turnip crops. Several hectares of mature plants were ploughed into the fields while the remainder was sold locally as livestock fodder. He comments on the lack of incentives and support given to farmers in his district, particularly those experiencing difficulties holding or consigning their produce.

In more recent times, improved understanding of the physiology of fruit and vegetables has resulted in a range of storage and distribution procedures which can be applied to reduce the risk of substantial post harvest losses. Food technologists commonly refer to harvested fruit and vegetables as living structures. When described in this manner, we’re reminded that most produce continues metabolizing following detachment from parent stock.

Fresh vegetables absorb atmospheric oxygen and release carbon dioxide, water, and heat. Within individual cells the metabolic breakdown of stores containing starch, sugars and organic acids results in molecules of carbon dioxide and water. Once detached from parent stock, these progressive water losses cannot be replaced by the distribution of sap through interior vessels. In combination with the prevention of microbial and insect challenges, contemporary post harvest technologies usually aim to reduce the metabolic rate of stored produce. Several of these involve chemical substances or procedures incompatible with the environmental and health precautions of organic certification standards.

There are a variety of economical ways to store organic vegetables but the best approach will depend upon each particular variety and the season. The majority of root crops can be stored satisfactorily in cool locations which are well protected from sunlight. When grown in small quantities, root vegetables such as parsnip and turnip can be left in the ground until required. One traditional storage method which remains popular in some developing regions is the ventilated pit. Hard vegetables including potatoes, turnip, and yam are carefully piled inside pits carved beneath the elevated facades of terrace slopes, hillsides and other suitably drained locations. The interior is usually insulated with layers of straw then covered with dry sand or earth to protect the vegetables from frost and extreme weather conditions. Underground cellars were once widely popular as a practical means for securing below ground storage. The better examples provided ventilation openings which enabled the circulation and removal of excessive humidity.

Careful handling then storage will enhance the longevity and nutritional value of organic vegetables. Bacterial mould is more likely to develop on bruised and damaged vegetables, and can rapidly spread to affect others. For this reason, it’s important to inspect stored crops regularly and remove any that have started to decay. Optimum results depend upon selecting the highest quality vegetables and rejecting any which are bruised or blemished. Many of the microscopic organisms causing mould and other forms of decay are unable to penetrate intact exterior skin but will readily invade through swollen areas and cuts. The portion of skin surrounding the stem is a frequent point of entry for microorganisms. As a general rule the rate post harvest decay is decreased by low storage temperatures and humidity. The highly controlled environments designed for commercial storage may also restrict circulating oxygen and prevent natural ripening with chemical treatments.

Following a successful harvest, I make efforts to store my vegetable groups separately and always avoid storing any type of fruit with vegetables. A non-functioning refrigerator or chest freezer can make a useful storage vessel for garden fresh vegetables. They offer protection from light and the insulation helps to maintain relatively constant temperatures within. Adequate ventilation can be ensured by drilling small holes in the door or lid sealings. They are inaccessible to rodents so can be safely housed outdoors in dry sheds and other suitable buildings. Larger vegetables like pumpkin, marrow, corn, and potatoes can also be stored in clearly labeled wooden or plastic boxes. The red skinned and other pigmented potatoes are particularly long lasting and may be stored for up to one year. Well-ventilated containers will accommodate several layers when required. Since it is important to minimize contact during storage, each new layer should be separated from those below with sheets of corrugated cardboard or similar. Onions and garlic will also last a considerable time but need to be properly aired in string bags or hessian sacks.

Depending on their variety and physical condition, many organic vegetables will benefit from refrigerated or frozen storage. According to food experts there are few nutritional disadvantages associated with snap frozen vegetables or those correctly accommodated in refrigerated stores. Because vegetable varieties respond differently according to their physiology, it can sometimes be challenging to select refrigeration temperatures suitable for a range of seasonal and imported produce. Provided there’s no risk of cold injury, maximum storage life is usually obtained by approaching but not exceeding the freezing point of tissue. In vegetables not susceptible to cold injury, maximum storage life can be obtained by storage close to the freezing point of the tissue. By maintaining an even temperature around four degrees celcius the durability of leafy greens, peas, corn, and asparagus can be extended over several days despite fluctuations or extremes of local temperature. Given they’re in perfect condition, a wide range of organic vegetables can also be frozen for several months without losing their nutritional quality or flavors. To prevent scarring and discoloration, crisp fleshy vegetables like beans, cauliflower, and broccoli should be blanched in boiling water for sixty seconds before freezing.

Within a short period of time refrigerated cold storage may interfere with the overall quality and flavor of root and tuberous vegetables. Refrigeration tends to encourage the conversion of starches to sugar, resulting in vegetables with poor texture and less robust flavors. When stored at temperatures above fifteen degrees celcius, many potato varieties will exit their dormant stage and commence sprouting. This can usually be delayed by storage systems which avoid unnecessary light, humidity, and close proximity with other produce. Dependent on their codes of practice, some commercial distributors may apply chemicals or radiation to suppress sprouting in their potato consignments. Maleic hydrazide (MH), isopropyl-phenylcarbamate (IPPC), and methyl naphthaleneacetic (MENA), are all commercial sprout inhibitors. All of these chemicals are potentially harmful and remain subject to legal restrictions or total bans imposed by organic certifiers.

Just two blocks down from my daughter’s house there’s a small grocery store stocking an exclusive range of organically certified sweet relish, pickles, and salsas. I always purchase a few jars of their spicy vegetable pickle. It’s terrific for firing up a ploughman’s lunch. Before refrigeration, food preservation techniques were an essential component of household management. Given sufficient time, spare vegetables can still be transformed into a wide range of traditional and exotic accompaniments. Zucchinis, onion, carrot, beetroot, and many others can be gently simmered with vinegar, sugar and combinations of spices, apple, tomato, and raisins. When properly sealed in preserving jars, home made relish and chutneys store on the shelf for up to twelve months. From my experience, food preservation tends to encourage resourcefulness and reduces the potential for waste. Produce falling below a premium standard can also be processed into juices or purees then frozen for up to one month before being used in soups and other recipes.

An essential consideration when storing fresh fruit is to ensure that only the highest quality examples are selected in the first place. As an organic producer, the objective is always to provide a safe, nutrient rich environment, one which enables healthy fruit to develop without the assistance of toxic pesticides and other chemical additives. Fruit which has been nurtured appropriately from the earliest stages will always store more easily, and remain fresher than produce which has been compromised by adverse growing conditions or bad management. There are few long term advantages to be gained from storing crops which are in poor condition.

Most fruit can be stored in a variety of ways. Any decision regarding the most suitable approach to storage will ultimately depend upon the quality and condition of the fruit combined with a realistic understanding of potential applications and consumer demand. In comparison to conventionally grown produce, organic fruit provides consumers with an assurance that biologically integrated methods were chosen in preference to others which might have improved efficiency at the ultimate expense of safety. To remain consistent, reputable organic producers must maintain these standards throughout the distribution chain. This requires an optimum level of understanding and practical co-operation with the relevant wholesalers, retailers, and other suppliers.

The optimum storage of fresh fruit in bulk quantities depends upon a clean, secure, and temperature controlled environment. Fresh produce chillers are normally set between four and ten degrees Celsius. To ensure premium freshness and longevity, a cool, even temperature must be maintained at all times, however, many individuals argue that chilling fresh fruit in cold storage decreases the flavour and alters the natural texture. In such cases, a slightly higher temperature is satisfactory, providing that the storage period is decreased and that local humidity is naturally low or can be easily controlled. An elevated humidity accompanying higher storage temperatures will increase the likelihood of promoting fungal growth and bacterial decay in stored fruit.

Unlike conventional growers, suppliers of organically certified produce do not use sprays or chemicals to restrict natural organisms. Most certification bodies also restrict the use of emulsions, waxes, and coatings similar to those which are routinely sprayed on conventional produce to enhance appearance and prolong storage capabilities. There are ethical and statutory guidelines which encourage organic food to be delivered to the consumer in an unaltered state. For organic certified produce, there must be no detectable levels of chemical contamination or environmental pollutants. These include emissions released from hydrocarbon fuels, industrial refrigeration, and cleaning solvents.

Given these restrictions, one of the difficult challenges lies in maintaining an adequate level of ventilation without compromising the biological integrity of the stored produce. Since many of the conventional pest controls are viewed as potential contaminants, the storage environment for organic produce requires a higher level of physical security. The most common entry points for insects and other organisms attracted to fruit are windows, unsealed doors, ventilation shafts, drains, pipes, and cracks in flooring, ceiling, and wall panels. For small scale and domestic purposes, fresh fruit can be stored outdoors in sheds or garages, provided these are insulated and well removed from sources of contamination. It can be a good investment to purchase several refrigerators from a junkyard. Whether set at low temperatures or left unconnected, their insulated construction protects stored fruit against sudden shifts in temperature and secure sealed doors prevent access to unwanted insects, mice, and other organisms.

With the exception of stone fruit, grapes, berries, and most tropical fruits, extended storage periods of at least several months can be achieved under optimum conditions. Depending on the variety, apples and pears can last for up to six months. The cardboard packing trays used by large producers and wholesalers are an excellent technology to ensure that fruit is well separated and that air can flow easily between stacked layers. Once harvested, humidity is unacceptable for citrus fruits which must be carefully stored in a cool and dry location. As with all fruit, they must be stored separately from other produce, particularly the root vegetables. The only exceptions to this rule are the culinary herbs which can be stored safely alongside citrus fruit. In regions surrounding the Mediterranean and Adriatic seas, it was traditional practice to store citrus fruit such as oranges, lemon, and grapefruit alongside dried rosemary, basil, and other aromatic herbs in underground cellars. It is now accepted that such herbs contain antiseptic and antibacterial properties which probably help to maintain a clean, microbe controlled environment.

Seasonal fruit like peaches, cherries, apricots, grapes, and berries are suitable for short periods of fresh storage, up to one month in good conditions. All types of fruit must be periodically checked during their storage period. There is a popular wisdom suggesting that one bad apple left unattended will spoil an entire bunch. In the case of fruit storage, this is literally true. Any fruit exhibiting signs of decay should be removed immediately to prevent further contamination. Whenever large quantities of stored fruit begin to simultaneously rot, the most likely cause is some combination of inappropriate storage duration, poor handling techniques, problems with controlled climate conditions, or poor quality produce to begin with.

Large quantities of seasonal fruit which cannot be immediately released onto fresh markets are often sun dried, industrially dehydrated, or used as an ingredient for preserves, sauces, and other condiments. For stabilising their premium quality fruit, most organic growers tend to prefer traditional methods of sun or oven drying. Industrial dehydration is a fast and efficient process which will accommodate large quantities with minimal waste. Often selected by large scale producers and fruit growing cooperatives, the main disadvantage with these applications is the inclusion of chemical drying agents, preservatives, and, on some occasions, flavour enhancers. Creating a healthy range of preserves, juice, sauces, and other condiments eliminates waste by enabling the organic grower or wholesale distributor to process and store any fruit that is slightly bruised, discoloured, difficult to handle or to sell in large quantities.

Juicing is one of the simplest means of storing fruit. Centrifugal or cold pressed extraction is used for high quality processing. Both methods ensure enhanced protection of essential nutrients, particularly compared to those incorporating high temperatures, pressure, and chemical emulsifiers. Similar to other manufactured food products, chemical additives are widely used to alter the flavour, texture, colour, and nutritional properties of some packaged juices. Without the inclusion of preservative, fresh juice must be refrigerated and has a very limited shelf life. Despite the potential inconvenience, it is much healthier to consume juices which are freshly extracted from certified organic produce without the addition of chemical food agents.

Almost any fruit can be used to make sweet jams and preserves. After picking, fruit is cooked until the texture breaks down, releasing a syrupy juice. With addition of cane sugar and a water soluble fibre known as pectin, the juice is transformed into a firm jelly which keeps well and can be easily spread on toast or used to flavour cakes, donuts, and other dessert recipes. The best approach is to work quickly, making smaller batches rather than attempting a large one. When cooking utensils are burdened with excessive fruit, their heating and evaporating surfaces are inadequate and will boil rather than simmer the fruit. Adding the recommended quantity of fruit, and an approximately equivalent measure of sugar, contents must be simmered quickly until the juices release.

If desired the juice can be strained to create a jelly that is free of seeds, skin, and other particles. Otherwise, the entire fruit portion can be included as a traditional jam preserve. Whatever the choice, each mixture must be transferred as quickly as possible into warm, sterilised glass jars with lids. Most berry fruits will set firm without additional pectin, however to be safe, it is possible to purchase sachets of this natural food agent from most health food and organic produce retailers. The other alternative is to add some finely chopped apple during the simmer, since apples are a particularly rich source of pectin. For those who prefer savoury as opposed to sweet flavours, chutney or relish are preserves containing fruit, vegetables, spices, and sugar. These condiments are traditionally used to accompany cheeses, meat, and bread.