It is of the highest importance in the canning industry, both for the reputation of the manufacturer and the health and comfort of the consumer, that the vegetables selected for canning be fresh, free from disease, and prepared in such a way that all adhering dirt or other foreign substances be excluded. The process of preparation for canning should begin as soon as possible after the harvesting of the vegetables, since a delay, especially at the high temperature which usually prevails at the time of canning, produces rapid deterioration, both as respects the quality of the vegetable and its flavor. After the proper cleaning and preparation of the fresh vegetables they are next subjected to the process of canning. It is then the vegetables are heated to a temperature of, or above, that of boiling water for a sufficient length of time to thoroughly destroy all the living germs and spores contained therein. The degree of temperature and the length of time of heating depend upon the nature of the vegetable substance, the size of its particles and of the package and the relative difficulty of preservation. Where only living organisms are present the proper temperature is that which will destroy the life of the germ. It is well known that spores from which fermentative germs may be developed are more resistant to the action of heat than the germ itself. When, therefore, spores of this kind are present, the temperature of heating must be higher and the time more prolonged, or, in lieu of this, the food should be heated on two or three consecutive days during which time any spores which may have been present will have developed into organisms and been killed. Some forms of vegetable materials are sterilized much more readily than others. For instance, the kernels of green Indian corn are of such a character and degree of hardness as to resist, with a considerable degree of success, the influence of heat on the life of the germs which they contain. In such cases it is customary to previously cook the vegetable substance before placing it in the cans. The cans should contain enough water to fill the interstices between the particles of vegetable matter. It is the practice in many instances to add a little salt and sometimes also sugar to this liquid. When the can is filled and closed the sterilizing is best completed by placing it in a strong boiler, which is then closed and heated by steam under a pressure of two or three atmospheres or even higher, namely, from 30 to 45 pounds and over per square inch. By heating under pressure in this way the development of any pressure in the can due to the production of steam is counterbalanced by the pressure without the can, so that a swelling or cracking of the can cannot take place. If the cans are heated in an open bath of water or brine it is customary to leave a small perforation in the top of the can through which the combined gas of the interior of the can may escape, and this vent is closed by a small drop of solder applied before or at the time of taking the cans from the bath. The canning of vegetables may also be done in a small way in the household and the principle on which this process is based is exactly the same as that set forth. The vegetables must be properly prepared, placed in the cans, and heated a sufficient length of time to destroy germs and spores, and the vent in the can stopped with solder. For family purposes the use of closed boilers for heating is not practical on account of the expense of securing such apparatus. All kinds of vegetables which are eaten in a cooked state can be preserved by the canning process. This cannot be applied, however, to those forms of vegetables which are eaten raw, such as lettuce, radishes, etc.🏁

It is of the highest importance in the canning industry, both for the reputation of the manufacturer and the health and comfort of the consumer, that the vegetables selected for canning be fresh, free from disease, and prepared in such a way that all adhering dirt or other foreign substances be excluded. The process of preparation for canning should begin as soon as possible after the harvesting of the vegetables, since a delay, especially at the high temperature which usually prevails at the time of canning, produces rapid deterioration, both as respects the quality of the vegetable and its flavor. After the proper cleaning and preparation of the fresh vegetables they are next subjected to the process of canning. It is then the vegetables are heated to a temperature of, or above, that of boiling water for a sufficient length of time to thoroughly destroy all the living germs and spores contained therein. The degree of temperature and the length of time of heating depend upon the nature of the vegetable substance, the size of its particles and of the package and the relative difficulty of preservation. Where only living organisms are present the proper temperature is that which will destroy the life of the germ. It is well known that spores from which fermentative germs may be developed are more resistant to the action of heat than the germ itself. When, therefore, spores of this kind are present, the temperature of heating must be higher and the time more prolonged, or, in lieu of this, the food should be heated on two or three consecutive days during which time any spores which may have been present will have developed into organisms and been killed. Some forms of vegetable materials are sterilized much more readily than others. For instance, the kernels of green Indian corn are of such a character and degree of hardness as to resist, with a considerable degree of success, the influence of heat on the life of the germs which they contain. In such cases it is customary to previously cook the vegetable substance before placing it in the cans. The cans should contain enough water to fill the interstices between the particles of vegetable matter. It is the practice in many instances to add a little salt and sometimes also sugar to this liquid. When the can is filled and closed the sterilizing is best completed by placing it in a strong boiler, which is then closed and heated by steam under a pressure of two or three atmospheres or even higher, namely, from 30 to 45 pounds and over per square inch. By heating under pressure in this way the development of any pressure in the can due to the production of steam is counterbalanced by the pressure without the can, so that a swelling or cracking of the can cannot take place. If the cans are heated in an open bath of water or brine it is customary to leave a small perforation in the top of the can through which the combined gas of the interior of the can may escape, and this vent is closed by a small drop of solder applied before or at the time of taking the cans from the bath. The canning of vegetables may also be done in a small way in the household and the principle on which this process is based is exactly the same as that set forth. The vegetables must be properly prepared, placed in the cans, and heated a sufficient length of time to destroy germs and spores, and the vent in the can stopped with solder. For family purposes the use of closed boilers for heating is not practical on account of the expense of securing such apparatus. All kinds of vegetables which are eaten in a cooked state can be preserved by the canning process. This cannot be applied, however, to those forms of vegetables which are eaten raw, such as lettuce, radishes, etc.🏁