EASY METHODS OF CANNING IN TIN
If the proper sanitary requirements are provided and instructions of
the cold-pack method of canning are followed, it is entirely safe and
practical to use tin cans for all kinds of fruits, vegetables and
other food products. Food poisoning--commonly called ptomaine
poisoning--and the effects ascribed to "salts of tin" result from
improper handling and improper preparation of the product before
packing, or from allowing the product to stand in the tin after it has
been opened. The raw food products used for canning in tin must be in
sound condition, just as they must be if put into glass containers.
It is true that canned foods may be rendered unfit for use by improper
handling of the product before packing and that decomposition may
occur after canning, owing to insufficient processing, improper
sealing or the use of leaky containers. This condition, however, is no
more likely to be encountered in foods put up in tin than in products
canned in other types of containers. You run no more danger of poison
from your own tin-canned products than from tin-canned food bought at
the store. Most canned foods if in a spoiled condition readily show
this condition by the swelling of the can or by odor or taste. Canned
foods showing such evidences of decomposition should not be used.
Certain foods which are high in protein, such as meats, peas, beans
and fish products, may undergo decomposition without making this
condition obvious to the senses. It is essential, therefore, that the
greatest care be taken to subject such products to proper preparation
and ample processing. It should be remembered that canned foods, after
opening the containers, should be treated as perishable products and
should be handled with the same precautions that are applied when
fresh products are being used.
ADVANTAGES OF CANS
Many housewives ask, "Why can in tin when we have always used glass
jars?" There are many advantages in canning in tin which we can well
consider. There is no breakage as in glass; you can handle the tin
cans as carelessly as you choose and you will not hear a snap or crack
indicating a lost jar. Furthermore, tin cans are easier to handle not
only in canning but in storing.
The expense each year of new tin covers or new tin cans is no more
than the purchase of new rubbers and the replacement of broken glass
jars. Furthermore, one big advantage of tin over glass is that tin
cans can be cooled quickly by plunging them into cold water
immediately upon removal from the canner, and thus the cooking is
stopped at the proper moment. The product is consequently better in
form and flavor than when the cooking is prolonged, as it must be in
glass jars. Many women like the large openings of cans because they
can make better packs than when using narrow-necked jars.
If you do not care to bother with the soldering you can purchase a
safe and simple device that will do the work for you. This device is
called a tin-can sealer. With a sealer no soldering is necessary.
Even an inexperienced person, by following directions carefully, can
seal a can as well as an experienced one. The sealed cans look exactly
like those purchased at the store. Two or three cans a minute can be
sealed with this device.
This is the way to operate a can sealer: Prepare the fruits and
vegetables as for any canning, following directions formerly given for
cold-pack canning.
After the fruits or vegetables have been properly prepared, blanched
and cold-dipped if necessary, place them in sanitary, solderless cans.
Put water or sirup on, according to directions. Put the top on the can
and place the can in the sealer.
Raise the can into the chunk by swinging the raising lever at the
bottom of the machine against the frame. Turn the crank, rapidly at
first, with the right hand, and at the same time push the seaming-roll
lever very slowly with the left hand until it will go no farther. This
is one of the most important steps in the use of the machine. Continue
to give the crank several turns after the seaming-roll lever has gone
as far as it will go. This completes the first operation or seam.
Continue turning the crank with the right hand, and with the left hand
pull the seaming-roll lever until it will go no farther in this
direction. After this has been done give the crank several more turns,
and the second and final operation is complete. Bring the seaming-roll
lever back to the middle position and remove the can. The can is then
ready for sterilization.
Before sealing a new lot of cans or after changing for a different
size of can, one or two of the cans about to be used should be tested
for leaks. If this is done and the cans stand the test it will be
unnecessary to test the remaining cans of that same lot. The following
is a simple and safe test:
Put one tablespoon of water into an empty can and seal. Have on hand a
vessel containing enough boiling water to cover the can. Set aside
and, as soon as bubbles disappear from the surface, immerse the can in
the hot water. This heats the water in the can and creates a pressure
within the can. Keep the can under the surface for two minutes, and if
by that time no bubbles rise from the can the can has been sealed
air-tight.
ADJUSTING THE SEAMING ROLLS
If bubbles rise from the can the seam is not sufficiently tight. If
this seam is not sufficiently tight the _second_ seaming roll needs
adjusting, provided the directions regarding seaming rolls given below
have been observed. To set the rolls proceed as follows: Loosen the
nut on the bottom of the seaming-roll pin. With a screw driver turn
the seaming-roll pin counter clockwise--that is, from right to left.
Turn very slightly and, while holding the seaming-roll pin with the
screw driver in the left hand, tighten nut with the right hand, and
test as before.
Occasionally it is well to compare the seam after the first operation
with the sample can which is sent with the machine.
If seaming rolls cut into the can they are set too close, and the
seaming-roll pin should be adjusted in the opposite direction from
above.
After adjusting, always test cans as suggested above before canning.
The seaming rolls are set before the machine leaves the factory and
should not require adjusting for some time, but I have found that
slight variations in cans may make adjusting necessary.
If for any reason the second seaming roll is brought into contact with
the can before the first operation is complete it may injure the can
seriously, thus preventing an air-tight seam.
If the first seaming roll is forced in too rapidly it may ruin the
seam. Push the seaming-roll lever gently and steadily, while turning
the crank with the right hand. This rolls the seam gradually. There is
no danger from bringing in the second seaming roll too quickly if the
first seaming roll has completed its work.
There are thus, as you see, two kinds of tin cans used in home
canning: The sanitary or rim-seal can, which is used with a sealer,
and the cap-and-hole can. The latter consists of a can, and a cover
which carries a rim of solder and is fastened on the can by the
application of heat.
The sanitary can has a cover a trifle larger than the diameter of the
can, thus leaving the full diameter of the can open for filling. That
part of the cover that comes into contact with the can is coated with
a compound or fitted with a paper gasket or ring which makes a perfect
seal when the cover is crimped on the can. Some mechanical device is
necessary for sealing this can, and this is the sealer.
Cans may be had with inside enamel or plain without any enamel. The
following fruits and vegetables should be canned in enamel-lined cans:
All berry fruits, cherries, plums, rhubarb, pumpkin, beets and squash.
All highly colored products should be canned in enamel-lined cans to
prevent the bleaching effect induced by their action upon the plain
tin. Some prefer to can fish and meat in the enamel-lined cans. Other
products not mentioned here may be canned in plain cans, since they
are less expensive than the enamel-lined cans.
Covers are lined in two ways, with the paper gasket and the compound
gasket. The compound gasket is merely a preparation, scarcely visible,
applied to the under side of the cover and is not easily damaged by
handling. The paper gasket is a ring placed on the under side of the
cover and must be handled carefully. If the paper gasket becomes
broken the cover must be discarded. To sterilize covers having the
paper gasket, place them in the oven for a few minutes, but _do not
wet them_, before sealing cans. Do not remove or handle paper gaskets.
When the cans are removed from the cooker the ends should be raised;
this is caused by the pressure within. If they are not raised at the
ends the cans should be carefully examined for defects. After the cans
are sterilized they should be cooled off in water. This will cause the
ends to collapse. If they do not collapse the reason is probably due
to overfilling. It must be remembered that peas, beans and corn swell
a certain amount after water is placed in the cans; therefore, in
canning these vegetables the cans should be filled only to within a
quarter of an inch of the top. If the pressure of the air from without
will not cause the end to collapse, it should be forced in by hand.
THE TINNING OUTFIT
Tin-can sealers are made to handle the regular Number 2, or pint
cans, and the Number 3, or quart cans. The sizes are interchangeable,
so that in a few minutes' time a Number 2 machine may be changed into
a Number 3 machine with the necessary attachments. So it is economy to
buy a machine with these attachments, as you can then use either pints
or quarts as you desire.
If you are selling to boarding houses and hotels you also will want
half-gallon and gallon cans. If you use these larger-size cans and
want the sealer you can get it for these sizes, but you must tell
exactly what you want when ordering.
The prices which I give are 1919 prices and are of course not
stationary. A sealer that will seal the Number 2 sanitary tin cans
costs $14. A sealer for Number 3 cans will cost the same amount. But
the ideal arrangement is the combination machine which can be used for
both the pints, Number 2, and the quarts, Number 3. This type of
sealer costs $16.50. A special machine is used for sealing the Number
10 or gallon cans, and its price is $35.
The price of the "winter can opener" is $17.00 for smaller size and
$19.50 for the larger one.
Several standard sizes of tin cans are in common use for canning
purposes, as follows:
DIAMETER OF
NUMBER SIZE OPENING
INCHES INCHES
1 2-5/8 by 4 2-1/16
2 3-5/16 by 4-9/16 2-1/16 or 2-7/16
3 4-1/8 by 4-7/8 2-1/16 or 2-7/16
10 6/3/16 by 6-7/8 2-1/16 or 2-7/16
The cans are put up in crates holding 100 or 500 cans. If you are
canning for the ordinary market use Number 2 cans for berries, corn,
peas and cherries; Number 3 cans for tomatoes, peaches, apples, pears
and sweet potatoes.
In buying cans it is always necessary to state whether you desire
plain tin or lacquered--enameled--cans. In buying caps always ask for
the solder-hemmed caps and give the diameter of the can opening. For
whole fruits and vegetables, cans with two-and-seven-sixteenth-inch or
even larger openings are preferable. Since the size of the can opening
varies and it ordinarily will not be advisable to have more than one
capping iron, it is recommended that the larger
size--two-and-seven-sixteenth-inch--capping iron be purchased.
The tin cans come in lots of 100 or 500 cans. It is possible to buy as
few as two dozen cans, but that never pays. It is cheaper to buy a
larger quantity. Number 2 plain sanitary cans in 500 lots cost $3.45 a
hundred; in 100 lots, $3.65 a hundred. Number 2 sanitary
cans--enameled--in 500 lots cost $3.80 a hundred; in 100 lots, $3.95 a
hundred. Number 3, plain, in 500 lots are $4.50 a hundred; Number 3,
plain, in 100 lots are $4.70 a hundred. Number 3, enameled cans, in
500 lots, are $4.95 a hundred; Number 3, enameled cans, in 100 lots,
are $5.10 a hundred.
The gallons come twelve cans to a case. They are $1.40 a dozen if 100
cases are bought. If less than 100 cases are ordered they are $1.50 a
dozen.
The cans that you have to solder yourself run just about the same
price, Number 2 being $3.60 in 500 lots and $3.80 in 100 lots. Number
3 are $4.70 in 500 lots and $4.90 in 100 lots. The buyer must pay
express or freight charges on both sealers and tin cans.
PREPARING OLD CANS FOR REFILLING
Formerly, after using a tin can once we threw it away; but men with
brains, realizing this waste, have come to our rescue, and as a
consequence we can now use a can three times--that is, if we have a
sealer. The sealer that seals our cans will also open them for us, so
it becomes our winter can opener. With this can opener we can use our
tin cans three times, buying each year only new tops, which cost less
than good rubbers.
Cutting and Reflanging Tin Cans. Cutting off the can the first time.
First lift the spring pin in the top piece, push the lever from you,
drop the spring pin between the stop of the first operation roll and
the cutting-roll stop. Place the can in the sealer, push the
can-raising lever against opposite side of frame. Turn the crank and
gently push seaming-roll handle from you until you come against
cutting-roll stop, and the top of your can is cut off.
Reflanging. Remove standard can base and in its place put in the
reflanging base, lift the spring-pin and bring seaming-roll lever to
the original position. Drop the spring pin between the stops of the
first and second operation rollers, place the can in the sealer, open
end down, push raising lever round until the can engages with the
chuck, turn the crank and at the same time gradually push raising
lever round against the frame. The can is now ready for use again.
Resealing. The can is now three-sixteenths of an inch shorter than
originally. Remove the reflanging base, put one of the narrow washers
on the top of the can-raising lever, then the standard can base, and
the sealer is now ready. Proceed as with the original can.
Cutting the Can the Second Time. Proceed as at the first time, only
be sure to cut off the opposite end. The can may be cut open and
reflanged only twice, once on each end of the can body. In cutting and
reflanging the second time, leave the three-sixteenth-inch washer
under the can base and reflanging base.
Resealing the Second Time. Remove reflanging base and put the second
three-sixteenth-inch washer under the standard can base and proceed as
directed under resealing.
THE SOLDERING OUTFIT
The soldering equipment required includes a capping iron, a tipping
copper, soldering flux, a small brush, a porcelain, glass or stoneware
cup in which to keep the soldering flux: sal ammoniac, a few scraps of
zinc, solder, a soft brick and a file.
Soldering Flux. Soldering flux is a solution of zinc in crude
muriatic acid. It is used for cleaning the irons and for brushing the
tins and lead surfaces so as to make it possible for the melted lead
to adhere to the tin.
To Make the Flux. Purchase at the drug store ten cents' worth of
crude muriatic acid. Place this in a porcelain, stone or glass jar.
Add as much zinc in small pieces as the acid will thoroughly dissolve.
The flux is always best when it has stood from twelve to sixteen hours
before using. Strain through a piece of cloth or muslin. Dilute with a
little water, about half and half. This will make the soldering flux.
When using keep the flux well mixed and free from dust and dirt.
Tinning Capping Iron. Purchase five or ten cents worth of sal
ammoniac at the drug store; clean iron with file or knife. Mix a
little solder with the sal ammoniac. Heat the capping iron hot enough
so that it will melt the solder and convert it into a liquid. Place
the iron in the vessel containing the mixture of sal ammoniac and
solder. Rotate iron in the mixture until the soldering edge of the
iron has become bright or thoroughly covered with the solder. All
particles of smudge, burned material, and so forth, should be removed
from the iron before tinning.
Tinning the Tipping Copper. The tipping copper is tinned in very
much the same way as the iron. Sometimes it is desirable to file the
tipping copper a bit so as to make it smooth and to correct the point.
Heat the copper and rotate the tip of it in the mixture of sal
ammoniac and lead until it has been covered with the melted lead and
is bright as silver. The copper should be filed nearly to a sharp
point.
Capping a Tin Can. Use one tin can for experimenting. By capping and
tipping, heating the cap, and throwing it off and simply putting
another cap on the same can, you can use this one can until you become
proficient in capping.
When capping the full packs arrange the cans in rows upon the table
while the capping and tipping irons are heating in the fire. Take a
handful of solder-hemmed caps and place them on all cans ready to be
capped. Place a finger on the vent hole, hold cap in place, and run
the brush containing a small amount of flux evenly round the
solder-hemmed cap with one stroke of the hand. Do this with all cans
ready to be capped. Then take the capping iron from the fire. Insert
in center the upright steel. Hold the capping iron above the cap until
the center rod touches the cap and holds it in place. Then bring it
down in contact with all four points of solder-hemmed cap and rotate
back and forth about three strokes. Do not bear down on capping iron.
A forward and back stroke of this kind, if properly applied, will
perfectly solder the cap in place. Remove capping iron and inspect the
joint.
If any pin-holes are found recap or repair with copper. It may be
necessary to use a piece of wire lead or waste lead rim from a cap to
add more lead to the broken or pinhole places of a cap.
Tipping a Tin Can. Take flux jar and brush. Dip brush lightly in
flux and strike the vent hole a side stroke, lightly, with brush
saturated with flux.
Use the waste solder-hemmed cap rim or wire solder. Place point of
wire solder over vent hole. Place upon this the point of the hot,
bright, tipping copper. Press down with a rotary motion. Remove
quickly. A little practice will not only make this easy, but a smooth,
perfect joint and filling will be the result. The cans are now ready
for the canner. The handwork is all over, for the canner will do the
rest.
Precautions. Do not fill tin cans too full. Leave a one-eighth to
one-quarter inch space at the top of the can and see that the product
does not touch the cover. If any of the product touches the cover the
application of the hot iron produces steam, which may blow out the
solder, making it impossible to seal the can.
RULES FOR STERILIZING
Remember all fruits and vegetables are prepared for tin cans exactly
as they are for glass jars and the period of cooking or sterilizing is
the same. The following rules will help to avoid difficulties in the
operation of the various canning outfits:
For hot-water-bath outfits, whether homemade or commercial.
1. Support the cans off the bottom sufficiently to permit the
circulation of water under and round the cans.
2. Have the water cover the tops of the cans by at least one inch. The
heat and pressure must be equal on all parts of the cans.
3. Count time as soon as the water begins to jump over the entire
surface. Keep it jumping.
4. On removing the cans throw them into a sink with running cold water
or plunge them into a pail of cold water.
5. If the cans are laid on their sides the false bottom is not
necessary.
For steam-pressure and pressure-cooker canners the following
precautions should be observed:
1. Lower the inside crate until it rests on the bottom of the
steam-pressure canners. In the case of the pressure cooker put the
rack in the bottom of the cooker.
2. Have the water come to, but not above, the platform.
3. Tin cans can be piled one above the other.
4. When the canner has been filled fasten the opposite clamps
moderately tight. When this has been done tighten each clamp fully.
5. Have the canner absolutely steam-tight.
6. Allow the pet cock to remain open until live steam blows from it.
7. Close the pet cock.
8. After the gauge registers the correct amount of pressure, begin
counting the time.
9. Maintain a uniform pressure throughout the process.
10. When the process is completed allow the steam to escape gradually
through the pet cock. You can lift the pet cock slowly, using a pencil
or a knife. This can be done only with tin cans. If glass jars are
used the canner must be cooled before opening the pet cock. Blowing
the steam from the pet cock is likely to cause a loss of liquid from
the partly sealed glass jars.
11. Throw the tin cans into cold water.
12. If tin cans bulge at both ends after they have been completely
cooled, it indicates that they are spoiling and developing gas, due to
bacteria spores or chemical action. These may be saved if opened at
once and resealed or resoldered and processed again for ten minutes.
The following table will help you in estimating how many cans of fruit
and vegetables you will obtain from a bushel of product:
NUMBER OF CANS A BUSHEL FILLS
NO. 2 CANS NO. 3 CANS
Windfall apples 30 20
Standard peaches 25 18
Pears 45 30
Plums 45 30
Blackberries 50 30
Windfall oranges, sliced 22 15
Windfall oranges, whole 35 22
Tomatoes 22 15
Shelled Lima beans 50 30
String beans 30 20
Sweet corn 45 25
Peas, shelled 16 10