The equipment required for canning depends on two things: the quantity of food to be canned at one time and, since there are several canning methods in use, the canning method that is to be employed.
Various kinds of elaborate equipment have been devised to make the work of canning easy as well as effective. However, it is possible to do excellent work with simple equipment, and if the matter of expense must be considered there should be no hesitation about choosing the simplest and least expensive and doing the work in the best possible way with it. It is important also that utensils already included in the household equipment be improvised to meet the needs of the canning season as far as possible.
Whatever the canning method that is to be followed may be, there are a number of utensils and containers that go to make up the general equipment that is required. Familiarity with such an equipment is extremely necessary for correct results in canning, and for this reason the general equipment is discussed here in detail. The special equipment needed for each of the canning methods, however, is not taken up until the method is considered. In giving this general equipment, mention is made of some utensils that are convenient but not absolutely necessary. Any unnecessary, but convenient, part of a canning equipment should therefore be chosen with a view to its labor-saving qualities and its expense. A device that will make the keeping of canned foods more certain and prevent loss may be a valuable purchase; still, that which makes for greater convenience, but not absolute saving, need not be considered a necessity.
The pots, kettles, and pans in ordinary use in the kitchen for cooking purposes are usually satisfactory for the canning of foods. Those made of tin or iron, however, are not so good as enameled ones or those made of other metals, such as aluminum. Especially is this true of utensils used for the canning of acid fruits or vegetables, because, if such food remains in contact with tin or iron for more than a few minutes, the acid will corrode the surface sufficiently to give the food a bad or metallic taste. In addition, such utensils often give the food a dark color. If enameled kettles are used for the cooking of foods that are to be canned, it is important that the surface be perfectly smooth and unbroken. Otherwise, it will be difficult to prevent burning; besides, chips of the enamel are liable to get into the food. Kettles for the cooking of fruits with sirup should be flat and have a broad surface. Fruit is not so likely to crush in such kettles as in kettles that are deep and have a small surface.
Many of the small utensils in a kitchen equipment are practically indispensable for canning purposes. Thus, for paring fruits and vegetables and cutting out cores, blossoms, and stem ends or any defective spots, nothing is more satisfactory than a sharp paring knife with a good point. For paring acid fruits, though, a plated knife is not so likely to cause discoloring as a common steel knife. There are, however, other useful implements for special work, such as the strawberry huller for removing the stems of strawberries,
and the peach pitter for removing the stones from clingstone peaches.
For placing the food to be canned into jars, both forks and large spoons are necessities. A large spoon with holes or slits in the bowl is convenient for picking fruits and vegetables out of a kettle when no liquid is desired, as well as for skimming a kettle of fruit. For packing foods into jars, a long-handled spoon with a small bowl is convenient. Still another useful small utensil is a short, wide funnel that may be inserted into the mouth of a jar and thus permit the food to be dipped or poured into it without being spilled.
Accurate measures are necessary in canning; in fact, some of the work cannot be done satisfactorily without them. A half-pint measuring cup and a quart measure with the cups marked on it are very satisfactory for making all measures.
Scales are often convenient, too. For measuring dry materials, they are always more accurate than measures. Many canning proportions and recipes call for the measurement of the ingredients by weight rather than by measure. When this is the case and a pair of scales is not convenient, it is almost impossible to be certain that the proportions are correct. For instance, if a recipe calls for a pound of sugar and an equal amount of fruit, a measuring cup will in no way indicate the correct quantity.
For the cleansing of fruits and vegetables that are to be canned, a colander is of great assistance; also, if a large wire strainer is purchased, it may be used as a sieve and for scalding and blanching, steps in canning that are explained later.
For household canning, the most acceptable containers for food are glass jars that may be closed air-tight with jar rubbers and tops. Use is sometimes made of bottles, jars, and cans of various kinds that happen to be at hand, but never should they be employed unless they can be fitted with covers and made positively air-tight. Like utensils, the glass jars that are a part of the household supply should be used from year to year, if possible, but not at the loss of material. Such loss, however, will depend on the proper sealing of the jars, provided everything up to that point has been correctly done. All jars should be carefully inspected before they are used, because imperfect or broken edges are often responsible for the spoiling of food.
In purchasing glass jars, only what are known as first quality should be selected. Cheap jars are likely to be seconds and will not prove so satisfactory. Glass jars may be purchased in sizes that hold from 1/2 pint to 2 quarts. If possible, food should be canned in the size of jar that best suits the number of persons to be served.
If the family consists of two, pint jars will hold even more than may be used at one time, while if the family is large the contents of a quart jar may not be sufficient.
Numerous types of glass jars are to be had. Some of them are more convenient than others and may be made air-tight more easily. These two features are the most important to consider in making a selection. Jars that close with difficulty, especially if the tops screw on, are not likely to keep food successfully because the bacteria in the air will have a chance to enter and thus cause the food to spoil.
Glass jars used for canning foods have improved with canning methods. The old-style jars had a groove into which the cover fit, and melted sealing wax or rosin was poured into the space surrounding the cover. Later came the screw-top jar.
This type of jar has been extensively used with excellent results. Both the mouth of this jar and the jar top, which is made of metal, usually zinc, lined with glass or porcelain, have threads that match, and the jar is sealed by placing the jar rubber over the top, or ridge, of the jar and then screwing the jar top firmly in place. Such jars, however, are more difficult to make air-tight than some of the newer types. One of these jars is illustrated here.
It is provided with a glass cover that fits on the ridge of the jar and a metal clasp that serves to hold the cover in place and to make the jar air-tight after a rubber is placed in position. Another convenient and simple type of glass jar, known as the automatic seal top, has a metal cover with a rubber attached.
Another improvement in jars is that the opening has been enlarged so that large fruits and vegetables, such as peaches, tomatoes, etc., can be packed into them whole. With such wide-mouthed jars, it is easier to pack the contents in an orderly manner and thus improve the appearance of the product. Besides, it is a simpler matter to clean such a jar than one that has a small opening.
While the tops, or covers, for glass jars are made of both metal and glass, as has been stated, the glass tops meet with most favor. Of course, they are breakable, but they are even more durable than metal tops, which are usually rendered less effective by the bending they undergo when they are removed from the jar. Covers made of zinc are being rapidly abandoned, and it has been proved that the fewer the grooves and the simpler the cover, the more carefully and successfully can it be cleaned. For safety, glass tops that have become chipped or nicked on the edges that fit the jar should be replaced by perfect ones. The covers for automatic-seal jars must be pierced before they can be removed, and this necessitates a new supply for each canning. If there is any question about the first-class condition of jar covers, whether of metal or glass, tops that are perfect should be provided.
Jar rubbers are required with jar tops to seal jars air-tight. Before they are used, they should be tested.
Good jar rubbers will return to their original shape after being stretched. Such rubbers should be rather soft and elastic, and they should fit the jars perfectly and lie down flat when adjusted. A new supply of rubbers should be purchased each canning season, because rubber deteriorates as it grows old. Rubbers of good quality will stand boiling for 5 hours without being affected, but when they have become stiff and hard from age it is sometimes impossible to make jars air-tight. Occasionally, two old rubbers that are comparatively soft may be used in place of a new one, and sometimes old rubbers are dipped in paraffin and then used. However, if there is any difficulty in sealing jars properly with rubbers so treated, they should be discarded and good ones used.
For household canning, tin cans are not so convenient as glass jars, but in spite of this they are coming into extensive use. The kind that may be used without any special equipment has a tin lid that fits into a groove and is fastened in place with rosin or sealing wax. Some cans, however, require that the lids be soldered in place. While soldering requires special equipment, this method of making the cans air-tight is the best, and it is employed where considerable canning is done, as by canning clubs or commercial canners.
In the purchase of tin cans, the size of the opening should receive consideration. If large fruits and vegetables, such as peaches, pears, and tomatoes, are to be canned, the opening must be a large one; whereas, if peas, beans, corn, and other small vegetables or fruits are to be canned, cans having a smaller opening may be chosen. When acid fruits or vegetables are to be canned, use should be made of cans that are coated with shellac, as this covering on the inside of the cans prevents any action of the acid on the tin.