GENERAL EQUIPMENT FOR CANNING

15.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.

16.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.

17. VESSELS FOR CANNING.--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.

[Illustration: FIG. 1]

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 thestrawberry huller, Fig. 1, for removing the stems of strawberries, and thepeach pitter, Fig. 2,[Illustration: 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.

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 quantity.

20. COLANDER AND WIRE STRAINER.--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.

21. GLASS JARS.--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 asfirst qualityshould 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.

[Illustration: FIG. 3]

22.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 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 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 in Fig. 4. 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 theautomatic 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.

[Illustration: FIG. 4]

23. JAR TOPS AND COVERS.--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.

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.

[Illustration: FIG. 5]

25. TIN CANS.--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.

GENERAL DISCUSSION

26.The methods employed for the canning of foods include theopen-kettle method, thecold-pack method, thesteam-pressure method, and theoven 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.

27. The OPEN-KETTLE METHODof 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.

31.TheCOLD-PACK METHODof 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, scraping, hulling, stemming, seeding, or cutting, depending on the kind. Then it isscaldedorblanchedand plunged into cold water quickly and taken out immediately, the latter operation being calledcold-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 andprocessed; that is, cooked and sterilized. When food that is being canned is subjected to processing only once, the method is referred to as theone-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 thefractional-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.

[Illustration: FIG. 6]

32. UTENSILS REQUIRED.--The utensils required for canning by the cold-pack method are shown assembled in Fig. 6. Chief among them is asterilizer, 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.

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.

[Illustration: FIG. 7][Illustration: FIG. 8]

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.

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 assists 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.

37. PACKING THE JARS.--Packing the jars immediately follows cold-dipping, and it is work that should be done as rapidly as possible. Remove the jars from the hot water as they are needed and fill each with the cold-dipped fruit or vegetable. Pack the jars in an orderly manner and as solidly as possible with the aid of a spoon, as in Fig. 10. Just this little attention to detail not only will help to improve the appearance of the canned fruit, but will make it possible to put more food in the jars.

[Illustration: FIG. 9][Illustration: FIG. 10]

When a jar is filled, pour into it whatever liquid is to be used, as in Fig. 11. As has been stated, hot sirup is added for fruits and boiling water and salt for vegetables. However, when fruit is to be canned without sugar, only water is added. With tomatoes and some greens, no liquid need be used, because they contain a sufficient amount in themselves.

38. PREPARATION FOR THE WATER BATH.--As the jars are filled, they must be prepared for the water bath. Therefore, proceed to place the rubber and cover on the jar. Adjust the rubber, as shown in Fig. 12, so that it will be flat in place. Then put the cover, or lid, on as in Fig. 13, but do not tighten it. The cover must be loose enough to allow steam to escape during the boiling in the water bath and thus prevent the jar from bursting. If the cover screws on, as in the jar at the left, do not screw it down tight; merely turn it lightly until it stops without pressure being put upon it. If glass covers that fasten in place with the aid of a clamp are to be used, as in the jar at the right, simply push the wire over the cover and allow the clamp at the side to remain up. Jars of food so prepared are ready for processing.

[Illustration: FIG 11]

[Illustration: FIG. 12][Illustration: FIG. 13]

39. PROCESSING.--The purpose of the water bath is toprocessthe food contained in the jars before they are thoroughly sealed. Therefore, when the jars are filled, proceed to place them in the water bath. The water, which was placed in the sterilizer during the preparation of the food, should be boiling, and there should be enough to come 2 inches over the tops of the jars when they are placed in this large vessel. In putting the jars of food into the sterilizer, place them upright and allow them to rest on the rack in the bottom. If the filled jars have cooled, they should be warmed before placing them in the sterilizer by putting them in hot water. On account of the boiling water, the jars should be handled with a jar lifter, as in Fig. 14. However, if the sterilizer is provided with a perforated part like that in Fig. 15, all the jars may be placed in it and then lowered in place.

When the jars are in place, put the tight-fitting cover on the sterilizer and allow the water to boil and thus cook and sterilize the food in the jars. The length of time for boiling varies with the kind of food and is given later with the directions for canning different foods. The boiling time should be counted from the instant the water in the sterilizer begins to bubble violently. A good plan to follow, provided an alarm clock is at hand, it to set it at this time, so that it will go off when the jars are to be removed from the sterilizer.

[Illustration: FIG. 14][Illustration: FIG. 15]

40. SEALING THE JARS.--After processing the food in this manner, the jars must be completely sealed. Therefore, after the boiling has continued for the required length of time, remove the jars from the water with the aid of the jar lifter or the tray and seal them at once by clamping or screwing the covers, or lids, in place, as in Fig. 16. Sometimes, the food inside the jars shrinks so much in this process that the jars are not full when they are ready to be sealed. This is illustrated in Fig. 17. Such shrinkage is usually the result of insufficient blanching, or poor packing or both. However, it will not prevent the food from keeping perfectly. Therefore, the covers of such jars of food must not be removed and the jars refilled; rather, seal the jars tight immediately, just as if the food entirely filled them. If, in sealing jars removed from the water bath, it is found that a rubber has worked loose, shove it back carefully with the point of a clean knife, but do not remove the cover.

[Illustration: FIG. 16][Illustration: FIG. 17]

As the jars are sealed, place them on their sides or stand them upside down, as in Fig. 18, to test for leaks, in a place where a draft will not strike them and cause them to break. If a leak is found in any jar, a new rubber and cover must be provided and the food then reprocessed for a few minutes. This may seem to be a great inconvenience, but it is the only way in which to be certain that the food will not be wasted by spoiling.

[Illustration: FIG. 18][Illustration: FIG. 19]

41. WRAPPING AND LABELING.--When the jars of food have stood long enough to cool, usually overnight, they are ready for wrapping and labeling. Wrapping is advisable for practically all foods that are canned, so as to prevent bleaching, and, of course, labeling is necessary when canned food is wrapped, so as to enable it to be distinguished readily when it is in storage. To wrap canned foods, proceed as in Fig. 19. Use ordinary wrapping paper cut to a size that will be suitable for the jar, and secure it in place with a rubber band, as shown, or by pasting the label over the free edge.

42.In canning food by the FRACTIONAL-STERILIZATION CANNING METHOD, the procedure is much the same as in the one-period cold-pack method. In fact, the only difference between the two is that blanching and cold-dipping are omitted, and in their stead the food in the jars is subjected to three periods of cooking. When the jars of food are made ready for processing in the sterilizer, they are put in the water bath, boiled for a short time, and then allowed to cool. After 24 hours, they are again boiled for the same length of time and allowed to cool. After another 24 hours, they are subjected to boiling for a third time. Then the jars of food are removed and sealed as in the one-period cold-pack method. By the fractional-sterilization method, the spores of bacteria contained in the food packed in the jars are given a chance to develop during the 24-hour periods after the first and second cookings, those which become active being destroyed by cooking the second and third times. Although some canners prefer this method to those already mentioned, the majority look on it with disfavor, owing to the length of time it requires.

43.For canning foods by steam pressure, special equipment is necessary. In one of the steam-pressure methods, what is known as awater-seal outfitis required, and in the other a device called apressure cookeris employed. The work of getting the containers ready, preparing the food for canning, packing it into the jars, and sealing and testing the jars is practically the same in the steam pressure methods as in the cold-pack methods. The difference lies in the cooking and sterilization of the foods after they are in the jars and partly sealed and in the rapidity with which it may be done.

44. CANNING WITH A WATER-SEAL OUTFIT.--A water-seal outfit, which may be purchased in stores that sell canning supplies, consists of a large metal vessel into which fits a perforated metal basket designed to hold jars of food. This vessel is also provided with a tight-fitting cover having an edge that passes down through the water, which is placed in the bottom of the vessel. When heat is applied to the bottom of the vessel, the water inside of it is changed into steam. The cover prevents the steam from passing out, and it collects in and around the metal basket supporting the jars of food. Enough steam is generated in this outfit to raise the temperature about 4 to 6 degrees above the boiling point. Thus, the water-seal outfit will cook the food in the cans in about one-fourth less time than will the water bath of the one-period cold-pack canning method.

[Illustration: FIG. 20]

45. CANNING WITH A PRESSURE COOKER.--For canning by steam pressure, a number of different kinds of pressure cookers are to be had, but in principle they are all alike and they are always made of heavy material, so as to withstand the severe steam pressure generated in them. In Fig. 20 is shown one type of pressure cooker. It is provided with a bail, or handle, for carrying it and with clamps that hold the cover firmly in place. Attached to the cover is a steam gauge, which indicates the steam pressure inside the cooker, and a pet-cock, which is used to regulate the pressure. On some cookers, a thermometer is also attached to the cover. Also, inside of some, resting on the bottom, is an elevated rack for supporting the jars of food that are to be sterilized and cooked. In operating a pressure cooker, water for generating steam is poured in until it reaches the top of this rack, but it should not be allowed to cover any part of the jars of food. Steam is generated by applying heat to the bottom of the cooker, and the longer the heat is applied the higher the steam pressure will go.

It is possible to secure a steam pressure of 5 to 25 pounds per square inch in a cooker of this kind. This means that the temperature reached will vary from a few degrees above boiling to about 275 degrees Fahrenheit. At a pressure of 20 pounds, the temperature will be about 260 degrees. The heavier the material used for a cooker and the more solid the construction, the higher may go the steam pressure, and, of course, the temperature. Some cookers of light construction will not permit of a pressure greater than 5 pounds, but even such cookers are very satisfactory. It is the high temperature that may be developed in a pressure cooker that greatly shortens the time required for cooking jars of food and making them sterile.

46.For canning food in some tin cans, it is necessary to have a soldering outfit for properly closing them. This consists of a capping steel, a tipping iron, solder in small strips and in powder form, a small can of sal ammoniac, and a bottle of flux, which is a fluid that makes solder stick to tin.

47.Prepare the food that is to be canned in tin cans in the same way as for canning in jars by the cold-pack method; likewise, pack the cans in the same way, but allow the liquid and fruit or vegetables to come to within only 1/4 inch of the top. Then proceed to close the cans. Apply the flux to the groove in the top of each can where the solder is to be melted, using for this purpose a small brush or a small stick having a piece of cloth wrapped around one end. Heat the capping steel, which should be thoroughly clean, until it is almost red hot, dip it quickly into a little of the flux, and then put it into a mixture consisting of equal parts of sal ammoniac and powdered solder until it is covered with bright solder. Put the cap on the can and apply the hot capping steel covered with the solder. Hold this device firmly, press it downwards, and turn it slowly as the solder melts and thus joins the cap to the can.

48.After the caps are soldered in place, the air inside the cans must be driven out through the small vent, or opening, usually in the center of the cap, and the cans made air-tight. Therefore, place the cans into boiling water to within 1/2 inch of the top and let them remain there for a few minutes. Usually, 3 minutes in boiling water is sufficient. Immediately afterexhausting, as this process is called, apply a little of the flux as in capping, and, with the tipping iron well heated and a strip of solder, seal the hole in the caps. After this is done, test each can for leaks by submerging it in water. If bubbles arise, it is an indication that the cover is not tight and must be resoldered.

49.The next step consists in processing the cans of food. This may be done either in a water bath or in a pressure cooker. If the cans are to be processed in a water bath, keep them in the boiling water just as long as glass jars of food would be kept there. If a pressure cooker is to be used, keep the cans in it for 6 to 40 minutes, depending on the steam pressure employed, the ripeness of the food or the necessity for cooking it, and the size of the cans employed. For canning meat or fish, processing in a pressure cooker is the most successful, as the high temperature reached in it kills bacteria, which are difficult to destroy at the boiling point.

As soon as the cans of food are removed from the water bath or the pressure cooker, plunge them into cold water to stop the cooking and prevent the food from getting soft and mushy. Then label the cans, so that no mistake will be made as to their contents.

50.In another method, the tin cans may be closed without soldering the caps on. The caps used in this case are different from those which must be soldered. They are forced in place by a hand-pressure machine that may be attached to a table. Otherwise the procedure is the same as that just given.

51.TheOVEN METHODof canning is thought to be very satisfactory by many housewives, but, as it is necessary to remove the covers after cooking the contents of the jars, food canned in this way is subjected to contamination, just as in the open-kettle method. In addition, the jars are difficult to handle in the oven, owing to the extreme heat that is required to cook the food in the jars.

52.In canning by the oven method, proceed by preparing the food as for the cold-pack canning method; also, fill the jars with fruit or vegetables and with liquid or sirup as in this method. Put the covers on the jars loosely, omitting the jar rubbers. Place the jars in a shallow pan of water, as in Fig. 21, and set the pan containing the jars into a stove oven, which should be only slightly warm. At the same time place the jar rubbers in a pan of boiling water, so that they may be sterilized as the food cooks. When the jars are in the oven, increase the heat gradually until the food in them boils. Then keep up a temperature that will allow the food to boil quietly for a period long enough to cook it soft and sterilize it. Usually, 30 to 45 minutes after boiling has begun will be sufficient. During the cooking some of the liquid in the jars evaporates. Therefore, when the jars of food are ready to be removed from the oven, have boiling water or sirup ready, remove the cover of each jar in turn, and fill the jar brimful with the liquid. Then place a sterilized rubber in place and fasten the cover down tight. The procedure from this point on is the same as in the other canning methods.

[Illustration: FIG. 21]

53.In canning, as in all other tasks related to cookery, the housewife's aim should be to do the greatest amount of work, and do it well, with the least effort on her part. The results she gets in canning, then, will depend considerably on the orderly arrangement of the utensils and materials with which she is to do the work. But of greater importance is the preparation she makes to eliminate as much as she can the possibilities of contamination, for, as has been repeatedly pointed out, success in canning depends on the absence of dangerous bacteria.

54.From what has just been mentioned, it is essential that everything about the person who is to do the work and the place in which the work is to done should be clean. Clean dresses and aprons should be worn, and the hands and finger nails should be scrupulously clean. The kitchen floor should be scrubbed and the furniture dusted with a damp cloth. Any unnecessary utensils and kitchen equipment should be put out of the way and those required for canning assembled and made ready for the work. The jars should be washed and the covers tested by fitting them on without the rubbers. If a glass cover rocks, it does not fit correctly; and if a screw cover will not screw down tight, it should be discarded. Without the rubber, there should be just enough space between the cover and the jar to permit the thumb nail to be inserted as is shown in Fig. 3. The edge of each jar and each glass cover should be carefully examined every time it is used, so that none with pieces chipped off will be used, as these will admit air. This examination is made by running the finger over the edge of the jar and the cover, as is shown in Fig. 4. The jars, covers, and rubbers should be put into pans of cold water, and the water should be brought to the boiling point and allowed to boil for 15 minutes or more while the fruit or vegetables are being prepared for canning. They should be kept in the hot water until the food is ready to be placed in them. In the one-period cold-pack method, it is not necessary to boil the jars, rubbers, and covers, but this may be done if desired.

To produce good-looking jars of food, the fruit or vegetables to be canned should be graded to some extent; that is, the finest of the fruits or vegetables should be separated and used by themselves, as should also those of medium quality. Often it is wise to use the poorest foods for purposes other than canning. The food may then be canned according to the chosen method, but by no means should methods be mixed. In handling the product after it has been cooked by the open-kettle method, any spoon, funnel, or other utensil must be thoroughly sterilized in the same way as the jars and their covers and rubbers; indeed, no unsterile utensil should ever be allowed to touch the food when a jar is being filled.

[Illustration: FIG. 22]

55.It is by the observance of such precautions as these, some of them seemingly unimportant, that the housewife will be repaid for her efforts in canning and be able to produce canned fruits and vegetables like those shown in color in Fig. 22. This illustration shows, with a few exceptions, such foods canned by the one-period cold-pack method, and merits close inspection. As will be observed, the jars are full and well packed and the color of each food is retained. Each can of food indicates careful work and serves to show the housewife what she may expect if she performs her work under the right conditions and in the right way. This illustration likewise serves to demonstrate that any food may be successfully canned by the one-period cold-pack method, a claim that cannot be made for the other canning methods. In fact, some of the foods illustrated, as, for instance, peas and corn, cannot be canned successfully by any other method.

56. CLASSIFICATION OF VEGETABLES.--To simplify the directions here given for the canning of vegetables, this food is divided into four groups, as follows:

1.Greens, which include all wild and cultivated edible greens, such as beet greens, collards, cress, dandelion, endive, horseradish greens, kale, mustard greens, spinach, New Zealand spinach, and Swiss chard.

2.Pod and related vegetables, which include asparagus, beans, both string and wax, Brussels sprouts, cabbage, cauliflower, eggplant, okra, peppers, both green and ripe, summer squash, and vegetable marrow.

3.Root and tuber vegetables, which include beets, carrots, kohlrabi, parsnips, rutabagas, salsify, sweet potatoes, and turnips.

4.Special vegetables, which include beans, both Lima and shell, corn, mushrooms, peas, pumpkin, sauerkraut, squash, succotash and other vegetable combinations, and tomatoes.

The convenience of this plan will be readily seen when it is understood that, with the exception of the special vegetables, the same method of preparation and the time given for the various steps in the canning process apply to all vegetables of the same class. Thus, if directions for a vegetable belonging to a certain class are not definitely stated in the text, it may be taken for granted that this vegetable may be canned in the manner given for another vegetable of the same class.

57. GENERAL DIRECTIONS.--The canning of vegetables may be most successfully done by the one-period cold-pack method. Tomatoes, however, because of the large quantity of acid they contain, may be canned and kept with little difficulty by the open-kettle method, but they will be found to keep their shape better if the cold-pack method is employed.

The time required for cooking any vegetable after it is packed in jars depends on the kind and the age. Therefore, if a vegetable is hard or likely to be tough, it may be necessary to increase the time given in the directions; whereas, if it is young and tender or very ripe, as in the case of tomatoes, the time for cooking may perhaps have to be decreased. Because, in altitudes higher than sea level, the boiling point of water is lower than 212 degrees Fahrenheit, the length of time for boiling foods in the water bath must be increased after an altitude of 500 feet is reached. Therefore, for every additional 500 feet over the first 500 feet, 10 per cent. should be added to the time given for the boiling in water. In case a pressure cooker is used, however, this is not necessary.

The canning directions here given are for 1-quart jars. If pint jars are to be used, decrease the salt proportionately; also, decrease the time for cooking in each case one-fifth of the time, or 20 per cent. If 2-quart jars are to be used, double the amount of salt and add to the length of time for cooking one-fifth, or 20 per cent. For instance, if a 1-quart jar of food requires 90 minutes, a pint jar of the same food would require 72 minutes and a 2-quart jar, 108 minutes.

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