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Food Preservation

Food preservation has been an essential activity throughout history. The very cycle of the seasons creates periods of shortage and abundance of different foods at different points of the year. This problem was only worsened with the development of agriculture as people sacrificed their mobility and came to rely on fewer sources of food, each with its own cycle of growing season. Only through human effort and ingenuity has it become possible to obtain some of these foods throughout the year.

Although some food may be damaged by chemical changes such as oxidation, most food is destroyed in storage by spoilage cause by living organisms such as molds, bacteria, and yeast. Food preservation techniques, therefore, depend upon killing or inhibiting the growth of these microorganisms.

Many of our most common means for preserving food have been with us since the beginning of history and can be found distributed in many different locations. Drying, pickling, fermenting, and smoking have all been incorporated into the foodways of cultures throughout the world. Although the methods are diverse, what they all have in common is an attempt to create an environment that is inhospitable to microorganisms such as molds, yeast, and bacteria.

Methods of Food Preservation

Drying is perhaps the oldest of all food preservation techniques. It also is one of the most simple in that it removes water, the ingredient needed for all forms of life to survive. This method has been particularly useful for meats, some fruits, and cereals. Those who are experienced with drying food rarely determine whether a product is sufficiently dehydrated by its weight. Rather they will usually judge whether it is dry by its texture and appearance. The primary disadvantage to this method is that it changes the nature and taste of the food and it requires proper storage once the drying is complete. Since moisture can form on the exterior of dried foods, ventilation must be maintained to reduce the possibility of condensation. any moisture on the surface will make it possible for molds to grow, thereby spoiling the remainder of the food.

A good example of preserving food through drying are the pumpkin mats made by the early Pawnee and Wichita peoples of Kansas. Historically, Native Americans grew pumpkins in gardens along the river banks. Strips of pumpkin were dried and woven into mats for storage. The dried pumpkin would be used to flavor soups and other dishes. Tribes such as the Kiowa and the Comanche often traded buffalo meat to the Pawnees and Wichitas for pumpkin mats.

Most of the other forms of food preservation used prior to canning and refrigeration employed naturally produced chemicals to retard the growth of organisms that produce spoilage. The smoking of meat and fish, for example, leaves compounds in the meat the destroy microorganism. smoking also partly preserves the meat by lowering its moisture content. Usually meat is soaked in brine or salted for a short time before smoking. The meat is then usually rinsed with warm water and allowed to drain before it is placed in the smokehouse.

Many containers are used for smoking meat. A sealed box or barrel may be used, but at one time many farms had a proper smokehouse for the large-scale preservation of meat. Generally such a building has a series of hooks for hanging the food, a fire box to provide the smoke, and small holes to create enough ventilation to draw smoke from the fire. In most cases the fire box is connected to the smokehouse with a small tunnel to reduce the amount of heat to which the food is subjected. This is to prevent the meat from being partly cooked.The house is often heated in the winter because smoke will not penetrate meat if it is frozen. many materials can e used to produce the smoke. Although chips from hardwoods such as hickory are often favored, bark and corn cobs are frequently used. Meat may be smoked for up to three weeks before it is properly done.

In the Croatian American community of Strawberry Hill in Kansas City, Kansas, families have traditionally made kobasica, a spicy sausage. many houses on the hill have smokehouses in their backyards, although not all are in use today. members of the community continue to enjoy kobasica whether it is smoked at home or at a neighborhood meat shop.

Meat also may be preserved by curing it in salt. This treatment is especially good for preserving fish. This can be done either by rubbing dry salt into the meat or by soaking it in brine. Salt or brine may be used to preserve vegetables as well. This method was once very common in the United States, but declined with the onset of the 20 century.

In fermentation the growth of specific microorganisms is encouraged. These beneficial microorganism in turn produce chemicals that inhibit the growth of those causing spoilage. Fermentation depends on the production of alcohol in the case of wine, acetic acid in the case of vinegar, or lactic acid in the case of sauerkraut to destroy or slow the growth of microorganisms. Fermentation of the kind used to make sauerkraut depends upon the properties of salt as well as the fermentation process. making sauerkraut combine a small amount of salt with the cabbage to prevent the growth of bacteria that cause the food to spoil immediately. The salt, however, does not prevent the growth of bacteria that cause the production of lactic acid. It is this lactic acid that prevents the growth of undesirable bacteria in the long term.

Sugar also has strong antiseptic qualities. Any substance that is composed of a minimum of 65 percent sugar is resistant to spoiling. For this reason fruit rarely needs to be fully dried to be preserved. Rather, it must only be dried to the point that 65 percent of its weight is composed of sugar. Fruit may be preserved in sugar in its whole state, as in candied fruit, or packed in a syrup, as in marmalades and preserves. In either case the fruit is first placed in a diluted sugar syrup to allow the sugar to fully penetrate the fruit. The concentration of sugar in the syrup is then increased until the fruit is fully saturated. Some molds will digest sugar, and for this reason a paraffin cap is often poured over jars of jelly or preserves. The paraffin prevents the growth of these molds by depriving them of air.

Canning

The ancient methods of food preservation remained unchallenged until the introduction of canning in the 18th century. The method was developed between 1795 and 1809 by Nicolas Appert of France. His research was initiated in response to a call from Emperor Napoleon Bonaparte for the discovery of a new method of food preservation to supply the army. Appert published his results in 1810 for which he received the prize of 12,000 francs.

Appert discovered the method through a series of painstaking experiments, but he never fully understood the reasons why canning worked. Since the germ theory had not been developed, he had no way of knowing that he was preventing spoilage by killing the microorganisms in the food and preventing the introduction of new organisms by sealing the containers. Rather, he thought air alone cause spoilage and that the heating of the air in the containers rendered it harmless. The total destruction of microorganisms in food was an entirely new approach to food preservation, one which made it possible to store food indefinitely.

At first Appert preserved food by placing it in bottles that were heated in a pot of boiling water. Later he experimented with pressure cookers. At first canned vegetables were a curiosity for the wealthy and could only be found in the most exclusive restaurants of Paris. Commercial canning, however, was underway before 1830. At this point metal cans rather than glass were introduced to reduce cost and the problems with breakage in transport. Although food was being canned in the United States in the 19th century, it was the need for canned foods to feed troops in the Civil War that largely promoted its use in our country. Troops returning home saw the value of this method of food preservation that, unlike most other means used at that time, had no special storage requirements.

During the 19th century most home canners did not employ the full sealed container method developed by Appert. Rather they used the so-called "open kettle" method. In this technique the food is placed in liquid and boiled. It is then quickly transferred to jars that have just been boiled and are still hot. Covers are then quickly placed on the jars In the southern United States canners often heated the food for decreasing lengths of time on three consecutive days to eliminate more of the spoilage-causing agents. The open kettle method worked fairly well for food with a high acid content such as tomatoes, rhubarb, pears, or peaches. Open kettle canning, however, frequently damages the fruits or vegetables and has a higher problem with spoilage.

The adoption of the more efficient can-cooked method for home use was dependent on two developments. The first of these was the production of pressure cookers at a cost that made this method economically feasible. Without the efforts of the agricultural extension services, however, it might have taken considerably longer before this technology was made available to the general public. One of the first efforts to disseminate this information was undertaken by the Louisiana Experiment Station in 1905. In the years that followed, home canning techniques were taught through a number of state extension services, leading to their widespread acceptance by the advent of the First World War. The need for food during wartime only served to increase the adoption of canning for home food preservation. Although time consuming, canning proved to be a much more versatile method than any used until that point. In the decades that followed, teaching canning techniques became standard in high school home economics classes. Only with the widespread use of freezers did canning encounter competition in the area of home food preservation.

As has been the case with other food related activities, canning eventually became a competitive activity at country fairs. often the prizes given have been provided by the canning companies themselves, and usually consist of cases of canning jars. Although agricultural extension services often taught the use of metal cans for the home, these are not generally able to compete. This is because the containers are rarely opened during competition; to do so would destroy the food. In addition, many canned foods must be cooked or prepared after being removed from the can. Tasting the raw contents, therefore, would answer few questions about the quality of the food. For these reasons, competition is usually based on the presentation of the food in the glass jars. Among the criteria used are the color and shape of the food, its distribution in the jar, and the presence of absence of fragments. Although these might seem like unimportant or superficial concerns to the uninitiated, they do relate directly to the economy and efficiency of home canning.

Conclusion

In the years that followed World War II, the American public practiced home food preservation less frequently. This is partly the result of the movement from farming to other occupations. Once the food used for preservation had to be purchased, it was economical to simply buy food that had already been preserved. Food preservation has declined among agricultural families as well. This is due in part to the declining cost of commercially preserved food. As is the case with most families, those living in rural areas also are feeling the pressure of increased responsibilities that demand more time from family members. This has significantly reduced the time that can be invested in activities such as canning.

In recent years, however, there has been a resurgence of interest in traditional food preservation. This is due in part to concerns for higher quality food and for health benefits from food free of synthetic preservatives. These concerns have created a new market for those who preserve food locally. This development ensures that home food preservation will continue to be a part of the American culture into the future.

Food Preservation

Traditions  1993 © KSHS

Entry: Food Preservation

Author: Kansas Historical Society

Author information: The Kansas Historical Society is a state agency charged with actively safeguarding and sharing the state's history.

Date Created: August 2012

Date Modified: June 2013

The author of this article is solely responsible for its content.