Woman's Institute Library of Cookery Volume V Part 9

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.

18. KNIVES, SPOONS AND OTHER SMALL UTENSILS.--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_, Fig. 1, for removing the stems of strawberries, and the _peach pitter_, Fig. 2, 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.

[Ill.u.s.tration: FIG. 1]

19. DEVICES FOR MEASURING.--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 quant.i.ty.

20. COLANDER AND WIRE STRAINER.--For the cleansing of fruits and vegetables that are to be canned, a colander is of great a.s.sistance; 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.

[Ill.u.s.tration: FIG. 2]

21. GLa.s.s JARS.--For household canning, the most acceptable containers for food are gla.s.s 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 gla.s.s 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 gla.s.s jars, only what are known as _first quality_ should be selected. Cheap jars are likely to be seconds and will not prove so satisfactory. Gla.s.s 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.

[Ill.u.s.tration: FIG. 3]

22. Numerous types of gla.s.s 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.

Gla.s.s 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 s.p.a.ce surrounding the cover.

Later came the screw-top jar shown in Fig. 3. 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 gla.s.s 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 s.c.r.e.w.i.n.g 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 ill.u.s.trated in Fig. 4. It is provided with a gla.s.s 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 gla.s.s 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.

[Ill.u.s.tration: FIG. 4]

23. JAR TOPS AND COVERS.--While the tops, or covers, for gla.s.s jars are made of both metal and gla.s.s, as has been stated, the gla.s.s 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, gla.s.s 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-cla.s.s condition of jar covers, whether of metal or gla.s.s, tops that are perfect should be provided.

24. JAR RUBBERS.--Jar rubbers are required with jar tops to seal jars air-tight. Before they are used, they should be tested in the manner shown in Fig. 5. 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.

25. TIN CANS.--For household canning, tin cans are not so convenient as gla.s.s 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.

[Ill.u.s.tration: FIG. 5]

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 sh.e.l.lac, as this covering on the inside of the cans prevents any action of the acid on the tin.

CANNING METHODS

GENERAL DISCUSSION

26. The methods employed for the canning of foods include the _open-kettle method_, the _cold-pack method_, the _steam-pressure method_, and the _oven method_. Of these, the open-kettle method is perhaps the oldest household method of canning, and it is still used by many housewives. The other methods, which are newer, seem troublesome to the housewife who is familiar with the open-kettle method, yet it will only be fair to give the new methods a trial before deciding which to use. The one-period cold-pack method has much to recommend it. Foods canned in this way undergo less change in form and flavor than those canned by the open-kettle method; besides, there is less danger of spoiling. In fact, many foods, such as vegetables and meats, that cannot be canned satisfactorily by the open-kettle method will keep perfectly if they are carefully preserved by the one-period cold-pack method. The steam-pressure method requires the use of special equipment, as is explained later. While it is a very acceptable canning method, it is not accessible in many homes. The oven method is liked by many housewives, but it offers almost the same chance for contamination as does the open-kettle method.

OPEN-KETTLE METHOD

27. The OPEN-KETTLE METHOD of canning is very simple and requires no equipment other than that to be found in every kitchen. It consists in thoroughly cooking the food that is to be canned, transferring it to containers, and sealing them immediately.

28. UTENSILS REQUIRED.--Not many utensils are required for the open-kettle canning method. For cooking the food, a large enamel or metal vessel other than tin or iron should be provided. It should be broad and shallow, rather than deep, especially for fruit, as this food retains its shape better if it is cooked in a layer that is not deep.

The other utensils for canning fruits and vegetables by this method are practically the same as those already discussed--measuring utensils, a knife, large spoons, pans for sterilizing jars or cans, covers, rubbers, and jars or cans into which to put the food.

29. PROCEDURE.--The first step in the open-kettle canning method consists in sterilizing the containers. To do this, first clean the jars, covers, and rubbers by washing them and then boiling them in clear water for 15 to 20 minutes.

Next, attention should be given to the food that is to be canned. Look it over carefully, cut out any decayed portions, and wash it thoroughly.

Sometimes roots, leaves, stems, or seeds are removed before washing, and sometimes this is not done until after washing. At any rate, all dirt or foreign material must be washed from foods before they are ready for canning.

After preparing the food, it must be cooked. If fruit is being canned, put it into the required sirup, the making of which is explained later, and cook it until it is well softened, as if preparing it for immediate table use. If vegetables are being canned, cook them in the same way, but use salt and water instead of sirup. When the food is cooked, transfer it to the sterile jars and seal at once with the sterile rubbers and covers. Then invert each jar to permit the food to cool and to test for leaks.

30. The danger of not securing good results with the open-kettle method lies in the possibility of contaminating the contents before the jar is closed and sealed. In addition to having the jars, rubbers, and covers sterile, therefore, all spoons and other utensils used to handle the cooked food must be sterile. Likewise, the jars must be filled to the top and the covers put on and made as firm and tight as possible at once, so that as few bacteria as possible will enter. If screw-top cans are used, the tops should not be twisted or turned after cooling, as this may affect the sealing. If jars leak upon being turned upside down, the contents must be removed and reheated and the jar must be fitted with another cover. Then both jar and cover must be sterilized and the contents returned and sealed immediately.

COLD-PACK METHOD

31. The COLD-PACK METHOD of canning differs from the open-kettle method in that the food to be canned is not cooked in a kettle before placing it in the jars and sealing them. In this method, the food to be canned is prepared by washing, peeling, sc.r.a.ping, hulling, stemming, seeding, or cutting, depending on the kind. Then it is _scalded_ or _blanched_ and plunged into cold water quickly and taken out immediately, the latter operation being called _cold-dipping_. After this it is placed into hot jars, covered with boiling liquid--boiling water and salt for vegetables, meats, fish, or soups, and boiling sirup for fruits. Then the filled jars are covered loosely and placed in a water bath and _processed_; that is, cooked and sterilized. When food that is being canned is subjected to processing only once, the method is referred to as the _one-period cold-pack method_; but when the food in the jars has not been blanched and cold-dipped and is processed, allowed to stand 24 hours and then processed again, and this operation repeated, it is called the _fractional-sterilization method_. The equipment required for the cold-pack canning method and the procedure in performing the work are taken up in detail, so that every point concerning the work may be thoroughly understood.

[Ill.u.s.tration: FIG. 6]

32. UTENSILS REQUIRED.--The utensils required for canning by the cold-pack method are shown a.s.sembled in Fig. 6. Chief among them is a _sterilizer_, or boiler, which consists of a large fiat-bottomed vessel fitted with a rack and a tight-fitting cover. A number of such devices are manufactured for canning by the cold-pack method, but it is possible to improvise one in the home. A wash boiler, a large pail, a large lard can, or, in fact, any large vessel with a flat bottom into which is fitted a rack of some kind to keep the jars 3/4 inch above the bottom can be used. Several layers of wire netting cut to correct size and fastened at each end to a 3/4-inch strip of wood will do very well for a rack. In any event, the vessel must be deep enough to allow the water to cover the jars completely and must have a tight-fitting cover. Besides a sterilizer, there are needed three large vessels, one for scalding the food that is to be canned, one for cold-dipping, and one for keeping the jars hot. To hold the food that is to be dipped, a sieve, a wire basket, also shown in Fig. 6, or a large square of cheesecloth must also be provided, and for placing jars in the water bath, a can lifter, a type of which is shown on the table in Fig. 6, may be needed. The remainder of the equipment is practically the same as that described under the heading General Equipment for Canning.

PROCEDURE IN THE ONE-PERIOD COLD-PACK METHOD

33. PREPARING THE CONTAINERS.--The first step in the cold-pack method consists in preparing the containers for the food. The jars, rubbers, and covers, however, do not have to be sterilized as in the open-kettle method. But it is necessary first to test and cleanse the jars and then to keep them hot, so that later, when they are filled and ready to be placed in the water bath, they will not crack by coming in contact with boiling water. The best way in which to keep the jars hot is to let them stand in hot water.

[Ill.u.s.tration: FIG. 7]

34. PREPARATION OF THE FOOD.--Attention should next be directed to the preparation of the food to be canned; that is, clean it and have it ready for the processes that follow. The fruits or vegetables may be canned whole or in pieces of any desirable size. What to do with them is explained later, when the directions for canning the different kinds are discussed. While the food is undergoing preparation, fill the sterilizer with hot water and allow it to come to the boiling point.

35. SCALDING AND BLANCHING.--When the food is made ready, the next step is to scald or blanch it. Scalding is done to loosen the skin of such food as peaches, plums, and tomatoes, so that they may be peeled easily. To scald such fruits or vegetables, dip them quickly into boiling water and allow them to remain there just long enough to loosen the skin. If they are ripe, the scalding must be done quickly; otherwise they will become soft. They should never be allowed to remain in the water after the skin begins to loosen. For scalding fruits and vegetables a wire basket or a square of cheesecloth may be used in the manner shown in Figs. 7 and 8.

Blanching is done to reduce the bulk of such foods as spinach and other greens, to render them partly sterilized, and to improve their flavor.

It consists in dipping the food into boiling water or suspending it over live steam and allowing it to remain there for a longer period of time than is necessary for scalding. To blanch food, place it in a wire basket, a sieve, or a piece of clean cheesecloth and lower it into boiling water or suspend it above the water in a closely covered vessel.

Allow it to remain there long enough to accomplish the purpose intended.

[Ill.u.s.tration: FIG. 8]

36. COLD DIPPING.--After the food to be canned is scalded or blanched, it is ready for cold-dipping. Cold-dipping is done partly to improve the color of the food. It stops the softening process at once, makes the food more firm and thus easier to handle, and helps to loosen the skin of foods that have been scalded. It also a.s.sists in destroying bacteria by suddenly shocking the spores after the application of heat.

Cold-dipping, in conjunction with blanching or scalding, replaces the long process of fractional sterilization, and is what makes the one-period cold-pack method superior to this other process. To cold-dip food, simply plunge that which has just been scalded or blanched into cold water, as in Fig. 9, and then take it out at once.