School and Home Cooking by Carlotta C. Greer Published: 1920
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DIVISION SEVENTEEN
FOOD PRESERVATION
LESSON CLXVI
THE PRINCIPLES OF PRESERVING FOOD
WHY FOODS SPOIL.--Most foods spoil or change readily,--fruits decay, milk
sours, butter becomes rancid, and meat putrefies. Knowledge concerning the
spoiling of foods makes it possible for the housekeeper to preserve foods
from one season to another; it gives her the assurance that her preserved
fruit will "keep."
The decay of foods is due largely to the existence of minute vegetable
organisms or microorganisms. These microorganisms are molds, yeasts, and
bacteria. The molds (see Figure 88) are visible to the naked eye, the
yeasts (see Figure 86) and bacteria (see Figure 89) are microscopic in
size. These plants exist everywhere, and in everything (except those
things in which the organisms have been destroyed and prevented from
reentering),--in the air, in and on foods, and all over our bodies. Like
all plants, these organisms require warmth, moisture, and food for their
most rapid growth. Oxygen is necessary for the growth of some of these
plants.
Many foods constitute nourishment for these organisms. It is because these
plants exist in foods and live upon them that changes in foods result. The
mold on bread and fruit, the odor from decaying meat and eggs, the
liquefaction of decayed eggs, and the gas from fermenting canned fruit are
caused by microorganisms existing and growing in these foods. The
following experiments show the growth of molds on food and other
materials:
EXPERIMENT 80: EFFECT OF AIR, LIGHT, AND DRYING UPON THE GROWTH OF MOLDS.
--Place a piece of bread on a saucer. Allow it to remain uncovered, in a
light place, at room temperature, for several days. Examine. What is the
condition (moist or dry) of the bread? Have molds grown upon the bread?
[Illustration: From Household Bacteriology, by Buchanan. FIGURE 88.--SOME
SPECIES OF MOLDS.]
EXPERIMENT 81: EFFECT OF MOISTURE AND LIGHT UPON THE GROWTH OF MOLDS.--
Sprinkle a thick piece of bread with water, place it on a saucer, and
cover with a jelly glass or any glass dish. Leave in a light place at room
temperature for several days. Examine. Is the bread moist or dry? Have
molds grown upon the bread?
From the results of Experiments 80 and 81 what would you say has caused
the molds to grow? What conclusion can you draw
from this concerning the growth of molds upon foods in damp and dry places
and in damp and dry weather? How should bread be stored in dry weather? In
damp weather? Give the reason for storing Dried Bread Crumbs as directed
in Lesson L.
EXPERIMENT 82: EFFECT OF MOISTURE AND DARKNESS UPON THE GROWTH OF MOLDS.--
Repeat Experiment 81, except the method of covering. Cover with an earthen
dish so that the light is excluded. Let it remain at room temperature for
the same length of time as given in Experiment 81. Have molds grown? How
does the growth compare in quantity with that of Experiment 81?
EXPERIMENT 83: EFFECT OF MOISTURE AND LOW TEMPERATURES UPON THE GROWTH OF
MOLDS.--Repeat Experiment 81, but place the bread on the lower shelf of
the refrigerator. After several days, examine. Have molds grown? How do
they compare in quantity with that of Experiment 81? What conclusion can
you draw from this concerning the temperature at which food liable to mold
should be kept?
EXPERIMENT 84: GROWTH OF MOLDS UPON CUT FRUIT.--Place pieces of apple,
banana, lemon, or other fruits on separate saucers and cover each with a
glass dish. Place some lemon or other fruit juice in a test tube and allow
it to stand. After two days examine. Have molds grown on all the fruits?
Do you notice any difference in the quantity of the molds on the different
fruits? Have molds grown on the fruit juice?
EXPERIMENT 85: GROWTH OF MOLDS UPON WHOLE FRUITS.--Place whole fruits,
such as apples and lemons, on saucers and cover with glass. After two days
examine. Have molds grown upon the whole fruits? If so, how do the molds
compare in quantity to those growing on cut fruit? Account for this
difference. Apply the results of Experiments 84 and 85 to the "keeping" of
fresh fruits.
EXPERIMENT 86: GROWTH OF MOLDS ON OTHER FOODS.--Place a piece of cheese
and a piece of meat on separate saucers and cover each with a glass dish.
After two days examine. Have molds grown upon these foods? Account for the
growth of molds upon these foods when no moisture was added to them.
Devise a method for keeping cheese free from mold. Give the reasons for
your method.
EXPERIMENT 87: GROWTH OF MOLD UPON WOOD.--Soak a bit of wood in water for
at least 15 minutes. Cover it with an earthen dish and let it stand at
room temperature for several days. Examine. Have molds grown upon the
wood? What has caused the molds to grow upon the wood? From this give
directions for the care of the wooden part of the dasher of an ice cream
freezer. Draw conclusions concerning the care of pastry and bread boards
and butter paddles after scrubbing. Draw conclusions concerning the
scrubbing, drying, and airing of wooden floors.
EXPERIMENT 88: GROWTH OF MOLDS UPON CLOTH.--Sprinkle a bit of cloth with
water. Cover with an earthen dish. Let stand a few days at room
temperature. Examine. Have molds (mildew) grown upon the cloth? What
caused the molds to grow? From this draw a conclusion concerning the care
of washed clothes, wet dish-cloths, towels, and wash-cloths.
EXPERIMENT 89: CONTAMINATION OF FRESH FOOD BY MEANS OF MOLDY FOOD.--Dip a
piece of bread in water and place it on a saucer. With a knitting needle,
place bits of mold at several points on the surface of the bread. Cover
with a glass dish. After several days examine. At what points on the bread
have the molds started to grow? What conclusion can you draw from this
concerning the placing of moldy food with fresh food? When fruit is
falling to the ground, tell how an orchard should be cared for. Explain.
The following experiments show the growth of bacteria on food:
EXPERIMENT 90: GROWTH OF BACTERIA.--Into test tubes put one of the
following foods: (1) bit of uncooked meat; (2) small quantity of egg; (3)
piece of bread; (4) crushed peas or beans; (5) sugar or syrup. Add a
little water to each tube. Set aside in a warm place. After several days,
examine. What change in appearance do you note? What has caused the foods
to spoil?
EXPERIMENT 91: EFFECT OF BOILING ON THE GROWTH OF BACTERIA.--Place a
little chopped meat in two test tubes. Add lukewarm water to each. Boil
the contents of one of the tubes for several minutes. Set both aside.
After 24 hours, examine. What difference is there in the condition of the
meat in each tube? Explain this difference. From the result of this
Experiment draw conclusions regarding the boiling of food to prevent
spoiling.
EXPERIMENT 92: EFFECT OF PRESERVATIVES ON THE GROWTH OF BACTERIA.--Beat
slightly an egg white. Add to it 1/2 cupful of water. Pour a little of
the diluted egg white into four test tubes. To three of the test tubes add
one of the following: (1) salt; (2) sugar; (3) vinegar. Put all of the
tubes in a warm place. After several days, examine. What is the condition
of the egg white in each tube? Explain. Draw inferences regarding the use
of "safe" preservatives to prevent foods from spoiling.
THE PRINCIPLES OF PRESERVING FOOD.--Food may be preserved by opposing the
growth of microorganisms or by destroying them. Low temperatures, certain
preservatives, and drying destroy microorganisms or retard their growth.
[Illustration: From Household Bacteriology, by Buchanan
FIGURE 89.-THE FOUR TYPES OF BACTERIA. A, cocci; B, bacilli; C, spirilla;
D, branched filamentous organism.]
Drying is effective in preserving such foods as fruits, certain
vegetables, fish, and meats. The drying of fruit and vegetables may be
done in the home. This process of food preservation is often advisable
when there is an excessive supply of fruit or vegetables in the orchard or
garden.
Substances known as preservatives are used in food preservation.
Some of these are harmless, as sugar, salt, vinegar, and spices. Others
are harmful, as formaldehyde, boric, salicylic, benzoic, and sulphurous
acids, with their related compounds. Saltpeter and smoke are also
preservatives. There is some doubt concerning the harmlessness of these
latter preserving agents. Foods preserved with harmful materials should
never be used. Good food materials can be preserved without the use of
harmful preservatives.
The destruction of microorganisms by heat is the basic principle of
preserving much food, especially fruit and vegetables. In order to
preserve fruits it is necessary to process them, i.e. to
apply heat in such a way as to insure preservation and secure the maximum
of good quality. To do this, the fruit must be cooked well, packed in cans
which have been boiled, and sealed to exclude the air from them. It is
necessary, also, to sterilize all utensils which come in contact with the
foods in the processes of cooking and sealing.
If canned fruits do not "keep," some microorganisms either in the fruit,
on the can, or on the utensils used in canning, have not been destroyed,
or the can has not been securely sealed. Slight flaws in the can or
rubbers which were not detected at the time of sealing may cause the
spoiling of carefully canned fruit. In the preservation of fruit, every
effort should be made to secure sound fruit, perfect jars, and good
rubbers, and to have the fruit and utensils perfectly processed, and the
jars securely sealed. Failure to accomplish these ends may result in much
loss of materials and time.
KINDS OF SPOILAGE.--As mentioned previously, canned foods spoil either
from imperfect processing or sealing. Different organisms growing in
preserved foods cause different kinds of spoilage. A discussion [Footnote
123: Adapted from Journal of Home Economics, Vol. X (July, 1918), pp. 329-
331, "A Consideration of the Canning Problem," by Elizabeth F. Genung.] of
the various kinds of spoilage follows:
(a) FERMENTATION OR "SWELL."--When canned foods spoil with a
production of gas, fermentation of the food is taking place. The visible
indications of such spoilage are gas bubbles in the jar and a bulging of
the lid of a jar or a distending of the top and bottom of a can. Because
of the latter condition, the term "swell" is used in the commercial
canning industry to designate this kind of spoilage. When fermentation
takes place, the lid of a jar may become loosened instead of bulged.
This type of spoilage is caused by the action either of yeast or of a
certain kind of bacterium which thrives best without air. It is usually
due to imperfect sterilization. Fermentation can usually be detected by
the presence of bubbles of gas in the jar and a loosening of the sealed
cover.
(b) Flat Sour is a kind of spoilage in which no gas is formed, but
acid is produced, giving the food a sour taste. In some cases of flat
sour, a milky deposit appears in the bottom of the jar which can be
detected if the container is glass. In other cases, no change in the
appearance of the jar and its contents takes place.
Little is known of the kind of organism producing flat sour. Whether or
not food thus spoiled is injurious also has not been determined.
Flat sour is probably due to imperfect sterilization.
(c) PUTREFACTION.--When putrefaction takes place, food decays and
disintegrates, or decay takes place with the production of a gas of a
disagreeable odor. This type of spoilage is readily detected. Food thus
affected is unfit for use.
Putrefaction is usually caused by imperfect sealing. It may result,
however, from imperfect sterilization.
(d) BOTULISM.--A bacillus termed botulinus sometimes grows
on canned foods, especially those rich in protein or lacking in acid. This
organism produces a violent poison in the food. But fortunately, the
poison may be destroyed by boiling the food for ten minutes. Hence, it is
advisable to boil canned food at least 30 minutes before using.
This should be done even though the food is to be served cold. It may
easily be cooled after boiling. When there is the least suspicion that
food is spoiled, it should be discarded.
QUESTIONS
Explain why boiled milk keeps sweet for a longer time than uncooked milk.
Why do foods need to be sealed to preserve them?
Why does cooked meat "keep" longer than uncooked meat?
LESSON CLXVII
PROCESSING WITH LITTLE OR NO SUGAR--CANNED FRUIT
JARS FOR CANNED FRUIT.--There are many types of fruit jars. Glass jars
rather than metal cans should be used for home canning. Jars should be
constructed so that there is no contact of the fruit with metal, hence a
jar having a glass cover is desirable. A large opening, simple
construction, ease in cleaning, and perfect sealing are characteristics of
good fruit jars.
Glass jars should be tested before using: Partly fill the jar with
water, adjust the rubber and cover, seal, invert the jar. Examine
carefully for leakage.
RUBBER RINGS.--Soft, elastic rubbers should be chosen. It is poor economy
to use old rubbers. Rubber after usage becomes hard and inelastic; it may
cause imperfect sealing and hence decay of the fruit.
In certain processes of canning, it is necessary to subject the jars
provided with rubber rings and covers to long periods of boiling or to the
intense heat of a pressure or steam cooker. When such a method is followed
it is especially necessary that rubber rings of good quality be used. To
meet this requirement, the United States Department of Agriculture advises
that rubber rings conform to the following:
1. Inside diameter of 2 1/4 inches (for the jar of standard size).
2. Width of ring or flange from 1/4 to 12/32 of an inch.
3. Thickness of 1/12 of an inch.
4. Tensile strength sufficient to "stretch considerably and return
promptly to place without changing the inside diameter."
5. Firm enough so that no crease or break shows after it has been tightly
folded.
SELECTION AND PREPARATION OF FRUIT FOR CANNING.--Select solid, and not
over-ripe, fruit. It is better to have underripe than over-ripe fruit.
Fresh fruits--if possible picked on the same day they are to be used--are
desirable for canning.
Most fruits should be washed before using. Quinces should be rubbed with a
coarse towel before they are washed. Berries and small fruits should be
washed before they are hulled or stemmed. Most small fruits contain so
much water that it is not necessary to add water for cooking. Hence such
fruits should be drained thoroughly after washing. If there are any
decayed or bruised spots on fruit, the damaged portion should be removed
completely.
Peaches and tomatoes may be peeled instead of pared. This is done by
placing the fruit in a wire basket and then immersing the basket in a
kettle of boiling water for 3 minutes. Remove the basket of fruit from the
hot water and plunge it for a moment in cold water. Drain, then peel the
fruit. If desired, cut into halves, quarters, or slices. After fruit is
peeled or pared, it can be kept from discoloring by covering with cold
water.
METHODS OF CANNING FRUIT
Several methods may be used for canning fruit:
(a) OPEN KETTLE.--This method consists of cooking the fruit in
water or sirup and pouring it into jars and sealing. The entire process of
sterilization takes place in the kettle before the food is poured into the
jars. Hence the name of the process,--Open Kettle.
For this method it is necessary to boil the jars and rubbers before
placing the food in them. This is done as follows:
Fill and surround jars with cold water. Cover lids and rubbers with cold
water. Gradually heat the water and allow it to boil for at least 15
minutes. Allow the jars, covers, and rubbers to remain in the boiling
water until just ready to use them. Do not touch the inside of the jars
and covers with your fingers. Immerse spoons, cups, knives, skewers, or
knitting needles used for testing fruits, in boiling water before using
them in contact with the foods. If corks are used for sealing bottles,
scald them also.
[Illustration: Courtesy of Merrill School FIGURE 90--CANNING
FOODS.]
If small juicy fruits are preserved by the open kettle method, no water
should be added. Add the sugar to them and allow them to stand until some
of the juice is drawn from them, then cook.
If tough fruits are canned by this method, first steam, then cook in
sirup, or first cook them in clear water, add the sugar, and finish
cooking.
Fruit may be canned with or without sugar. Usually some sugar is used.
However, some housekeepers contend that the fresh-fruit flavor is retained
better by reheating the fruit and adding the sugar just before it is
served. Different quantities of sugar may be used. If the fruit breaks
into pieces readily, cook in a thick sirup. The quantity of water used
with the sugar varies with the juiciness of the fruit. For each pound
of fruit use from 1/2 to 1 cupful of sugar with from 1/8 to 1 cupful of
water.
After cooking the fruit, adjust the rubber on the sterilized jar, fill the
jar (to overflowing) with the hot fruit and sirup, cover at once, and
seal. Invert the can and let it stand until cool.
(b) COLD PACK.--This method is followed by placing the prepared
food in a clean, tested, hot jar, covering the food with water or sirup,
adjusting the rubber ring and cover to the jar, and processing both the
jar and its contents in boiling water or steam.
Before placing the food in the jar, it may be blanched, i.e.
subjected to boiling water or steam. After blanching, the food is cold-
dipped, i.e. plunged into cold water. After the preliminary
steps, such as washing, paring, and cutting into pieces, foods may be
blanched and cold-dipped as follows:
Place the food in a cheese-cloth bag or in a wire basket and immerse it in
boiling water. Certain fruits are allowed to remain in the water from 1 to
5 minutes (see Table). (The time is dependent upon the kind of fruit.)
Then remove the product from the boiling water, dip it immediately in cold
water, remove at once, and drain for a few minutes. These two processes
are used for large firm fruits. Berries and all soft fruits are canned
without blanching and cold-dipping.
Whether the fruit is blanched and cold-dipped or not, place it in hot jars
to 1/2 inch of the top. If a sirup is desired, it may be made by using 1/4
to 1 cupful of sugar for each quart jar with from 2 to 3 cupfuls
of water. Adjust a new, wet rubber on the jar; fill the jar to 1/4
inch of the top with sirup or with boiling water. Place the cover on the
jar, but do not seal it tightly. If a screw top jar is used, screw on the
lid by grasping it with the thumb and little finger. If the jar has a bail
top, adjust the top bail only,--not the lower bail. Then process the jars
and their contents by placing in:
[Illustration: FIGURE 91.--RACK FOR HOLDING JARS. Note that the rack is
shaped to fit a wash boiler.]
(1) Kettle or clothes boiler provided with a rack (see Figure 91) or some
sort of false bottom such as strips of wood, straw, paper, or wire-netting
of one half inch mesh.
(2) Steam cooker (see Figure 18).
(3) Pressure cooker (see Figure 17).
If the kettle or wash boiler is used, rest the jars on the rack in the
container, fill the latter with enough hot water so that it extends to a
depth of one inch above the covers of the jars. Then boil the water. Count
the time of processing when the water begins to boil. Keep the water at
boiling temperature for the length of time given in the Table below.
If the steam cooker is used, place the filled jars in the cooker and steam
for a few minutes longer than when the jar is immersed in boiling water
(see Table below).
If the pressure cooker is used, process according to the length of time
stated in the Table given below.
After sterilizing fruit by any of these methods, remove the jars from the
container, seal, invert, and set them aside to cool in a place free from
draft. When cool, wash the outside of the jars, and label. Store in a
cool, dark cupboard. Wrapping each jar in paper before storing is advised.
Bail top jars may be tested for perfect sealing by loosening the top bail,
and lifting the jar by grasping its lid with the fingers. If the jar is
securely sealed, the lid will not come off, because of internal suction.
In case the lid comes off, remove the rubber, replace it with a new, wet
one, adjust the cover and again process for at least 1/3 of the original
processing period or not less than 10 minutes.
A DISCUSSION OF METHODS OF CANNING.--(a) While the open kettle is
not as safe a method of canning as the cold pack from the standpoint of
perfect processing, it is desirable for small watery fruits, especially
strawberries, since evaporation of some of the water takes place. It is
also generally used for fruits preserved with much sugar, such as
preserves, jams, conserves, etc. Many housekeepers find this method
desirable for canning tomatoes and beets. The skins may be removed from
the latter after cooking, thereby losing less coloring of the vegetable.
(b) The cold pack method of canning is very satisfactory for most
fruits and all vegetables. It is especially desirable for whole fruits or
for fruits in large pieces. The shape of the fruit may be preserved better
by this method than by the open kettle process. It is also a safer method
as far as satisfactory processing is concerned. Many housekeepers find it
easier than the open kettle method.
The blanching and cold-dipping of vegetables and fruits which may be one
of the steps in the cold pack method is thought to accomplish several
things:
1. To remove objectionable acids and flavors.
2. To make the foods more pliable for packing in the jars.
It was formerly thought that blanching and cold-dipping of vegetables
destroyed some of the bacteria and aided in processing the food. Recent
experimentation shows that these processes do not affect the bacteria and
have no value as far as the preservation of the food is concerned.
TABLE FOR CANNING FRUITS BY ONE PERIOD OF PROCESSING [Footnote 124:
Adapted from Farmers' Bulletin 1211, "Home Canning of Fruits and
Vegetables," Revised August, 1922.]
TIME OF PROCESSING IN PINT OR
FOOD TIME OF QUART JARS IN:
BLANCHING (a) (b)
Water Bath at Pressure
12 degrees F. or Steam Cooker 5 Pounds
Cooker
Minutes Minutes Minutes
Apples,
cut in pieces 1 1/2 20 to 30
Apricots 1 to 2 30 10
Blackberries,
Blueberries None 10 to 20 10
Cherries 1/4 25 10
Currants,
Dewberries,
Gooseberries None 10 to 20 10
Pears 4-8 in boiling sirup 20 to 30 10
[Footnote 125: Do not cold dip after blanching in boiling sirup.
Use the longer time of processing in the water bath for large
pears.]
Peaches 1 or until skin
is loosened 20 to 30 10
Plums None 20 to 30 12
Pineapples None 30 10
Raspberries None 10 to 20 10
Rhubarb None 20 to 30 10 to 15
Strawberries None 10 to 20 10
NOTE.--Use only fresh, sound fruits for canning.
Do not begin to count the time of processing in a water bath until the
water reaches the boiling point.
When different times of processing are given, as 20 to 30 minutes, use the
longer time for quart glass jars and the shorter for tin cans.
For altitudes higher than 1000 feet, increase the time of processing 10
per cent for each additional 1000 feet. For very high altitudes it may be
best to use a pressure cooker for certain fruits.
If fruits are packed tightly, time of processing should be increased.
DISCUSSION OF THE DIFFERENT DEVICES USED IN THE COLD PACK PROCESS.--(1)
The kettle or wash boiler provided with a rack is an inexpensive device.
It is satisfactory for processing fruits and acid vegetables; there is a
question whether non-acid vegetables may be processed in the hot water
bath even though they are processed on three successive days. It is
thought by some that the flavor of foods canned at low temperature,
i.e. not above 212 degrees F., is superior to that canned at a
higher temperature.
(2) The steam cooker is a convenient and satisfactory equipment to use for
canning fruits and some vegetables. It is more expensive, however, than
the kettle having a rack, but less fuel is required when using it.
(3) The pressure cooker is the most satisfactory from the standpoint of
processing. It is especially satisfactory for vegetables and meat, since a
much higher temperature than that of boiling water is maintained during
the processing period. The higher temperature also makes it possible to
process foods in a shorter time. However, it is thought by some that the
flavor of foods canned above 212 degrees F. is inferior to that canned at a
lower temperature. Moreover, the pressure cooker is a more expensive device
than either of the other two.
QUESTIONS
Why should processed jars, covers, and rubbers remain in boiling water
until just ready for use?
Why not touch the inside of jars and covers with the fingers?
Why should berries and small fruits be washed before hulling or stemming?
Why should decayed or bruised spots on fruits be removed completely before
canning the fruit?
Why is it that the cold pack method of canning is safer from the
standpoint of processing than the open kettle method?
Why should the jar containing fruit that is to be processed by the
cold pack method be filled to 1/4 inch of the top with sirup rather than
to overflowing?
Why should the covers of jars not be sealed tightly before placing in the
kettle or steamer used for processing?
Why is it unnecessary and undesirable to dislodge air bubbles in jars
containing food processed by the cold pack process?
When food is processed by immersing the jars in boiling water, why should
the water extend above the covers of the jars to a depth of one inch?
LESSON CLXVIII
PROCESSING WITH MUCH SUGAR--PRESERVES, JAMS, AND CONSERVES
EXPERIMENT 93: THE USE OF SUGAR AS A PRESERVATIVE.--Place 2 thin slices of
fresh fruit in a sauce dish. Sprinkle one of the slices generously with
sugar. Set the sauce dish aside for at least 24 hours. Examine. What
change has taken place in the fruit without sugar? What has caused the
change? Compare the sugared fruit with that without sugar. What conclusion
can be drawn concerning the use of sugar in preserving fruit?
PRESERVES
Sugar was mentioned as one of the preservatives used in the preservation
of food (see The Principles of Preserving Food). Sugar in large
quantity is unfavorable to germ life and hence is a most effective
preservative. Preserves are made by cooking fruit in a thick sirup
as in the Method of Canning (a) Open Kettle. A large
quantity of sugar is desirable as far as preservation is concerned; but
for flavor less sugar is usually to be preferred. Only a few fruits are
better when preserved with considerable sugar. Fruits best adapted for
preserving are strawberries, sour cherries, sour plums, quinces, currants,
and raspberries. For preserves, use 3/4 to 1 pound of sugar for 1 pound of
fruit. The less quantity of sugar should be used for peaches, plums,
quinces, currants, and raspberries; the greater quantity, for strawberries
and cherries. Use the quantity of water given in Method of Canning
(a) Open Kettle. Cook and seal as canned fruit.
JAMS
Jam is made as follows: Clean the fruit. If large fruits are used, pare or
peel them and cut into small pieces. If small fruits,--berries or grapes,
--are used, mash them. Cook the fruit in as little water as possible. When
the fruit is soft, measure it and add the sugar,--use 3/4 to 1 part of
sugar to 1 part of cooked fruit. Cook until thick, stirring to prevent
burning. Test the thickness by dropping from a spoon. If it falls in heavy
drops, the jam is sufficiently cooked. Pour into sterilized jelly glasses.
Cover the glasses with clean cloth or paper and set aside to cool and
stiffen. Melt paraffin. Pour it (hot) over the cold jam. Allow the
paraffin to harden and then cover the glasses with the lids. Wipe the
outside of the glasses, label, and store.
Fruit that is too soft or too ripe for canning or preserving may be used
for making jam.
MARMALADES
Marmalades are made much as jams. However, usually only the pulp and
juices of fruits are used. The fruit is first cooked, and the skins and
seeds removed before adding the sugar. In Orange Marmalade, the rind is
used.
CONSERVES
Conserves consist of a combination of two or more fruits. Nuts and other
materials are sometimes added. Conserves may be prepared as preserves,
i.e. cooking the ingredients with sugar, until thick; or as jam,
i.e. cooking the ingredients until tender, then adding the sugar
and cooking until thick. It is thought by some that the latter method
produces a finer flavor; it makes a product less tough and less sticky. In
the special recipes for conserves given in this text, the latter method is
followed.
ORANGE MARMALADE (I)
1 dozen oranges
1 grapefruit
6 lemons
Sugar
Weigh the fruit, slice it. To each pound of fruit add 1 quart of cold
water. Let the mixture stand for 24 hours. Then cook slowly for 2 hours.
Weigh the cooked fruit. Add an equal weight of sugar. Cook for 1 hour or
until it stiffens. Pour into sterilized jelly glasses, seal, and cover as
directed for Jams.
ORANGE MARMALADE (II)
1 dozen oranges
3 pounds sugar
2 quarts rhubarb
Rind of 6 oranges
Wash the fruit. Slice the oranges and cut the rhubarb into pieces. (Do not
peel the rhubarb.) Cook the oranges and rhubarb for 30 minutes. Add the
sugar and cook slowly for 2 hours or until thick. Pour into sterilized
glasses. When cool, seal and cover as directed for Jams.
CARROT MARMALADE
1 pound carrots
3 cupfuls sugar
2 lemons
1/2 teaspoonful salt
Wash, scrape, and chop the carrots. Extract the juice from the lemons. Put
the carrots and lemon rinds through a food chopper, cover them with water,
and cook until tender. Add the lemon juice, salt, and sugar to the cooked
mixture. Cook until it is thickened. Turn into sterilized jelly glasses.
Let stand until cool. Then cover with melted paraffin.
STRAWBERRY AND PINEAPPLE CONSERVE
Use equal quantities of strawberries and shredded pineapple. Cook the
shredded pineapple in the least possible quantity of water. When tender,
add the strawberries and cook until they are soft. Measure the fruit and
add three fourths as much sugar as fruit and a small quantity of salt.
Cook until thick (see Jams). Pour into sterilized glasses. Seal and
cover as directed for Jams.
CRANBERRY CONSERVE
1 quart cranberries
1 1/2 cupfuls water
1/4 pound raisins
1/2 pound California walnuts, chopped
1 orange,--juice and grated rind
1 1/2 pounds sugar
1/2 teaspoonful salt
Wash the fruit. Cook the cranberries in the water until the berries burst.
Strain. Add the remaining ingredients and cook 25 minutes or until the
mixture is thick (see Jams). Pour into sterilized glasses. When
cool, seal and cover as directed for Jams.
GRAPE CONSERVE
1/2 peck grapes
2 oranges,--juice and rind
2 lemons,--juice and rind
1 cupful chopped nuts
Sugar
1/2 teaspoonful salt
Wash the fruit. Remove the grapes from the stems; remove the skins from
the pulp. Cook the pulp until soft; strain, to remove the seeds. Place the
strained pulp and skins in a preserving kettle. Extract the juice from the
oranges and lemons, then put the rinds through a food-chopper. Add the
lemon and orange juice and rind to the grape mixture and cook for 1 hour.
Measure the mixture. Then add an equal quantity of sugar and the nuts and
salt. Continue cooking until thick (see Jams). Pour into sterilized
glasses. When cool, seal and cover as directed for Jams.
APRICOT CONSERVE
1 pound dried apricots
1 1/2 quarts water
Sugar
2 pineapples or
1 large can shredded pineapple
1/2 teaspoonful salt
Wash the dried apricots and soak them in the water. In the water in which
they were soaked, cook the apricots until tender. Press through a
colander. If fresh pineapples are used, shred them and cook, in as little
water as possible, until tender. Combine the cooked fruits and measure.
Add 1/2 as much sugar and the salt. Cook until thick (see Jams).
Pour into sterilized glasses. When cool, seal and cover as directed for
Jams.
PLUM CONSERVE
1 pound (1 1/2 dozen) plums
1/4 cupful chopped nuts
1 cupful seeded raisins
2 oranges
1 cupful water
1 1/4 cupfuls sugar
1/2 teaspoonful salt
Wash the plums, stone, and cut into pieces. Extract the juice from the
oranges. Put the rind through a food chopper. Mix the plums, raisins,
orange rind, and water. Simmer until the fruits and peel are tender. Add
the orange juice, sugar, nuts, and salt, and continue cooking until the
mixture has the consistency of marmalade. Pour into sterilized glasses.
When cool, seal and cover as directed for Jams.
QUESTIONS
How do Preserves differ from Canned Fruit?
How does Jam differ from Preserves?
How does Jam differ from Fruit Sauce?
Why does Jam "keep" better than Fruit Sauce?
Give method of sealing Canned Fruit and method of sealing Jam. Explain why
different methods are used.
LESSON CLXIX
PROCESSING WITH MUCH SUGAR--JELLIES
EXPERIMENT 94: PECTIN IN FRUIT JUICE.--Put a few grapes, slices of apple,
or cranberries in a small saucepan, and add enough water to cover and cook
until the fruit is tender and soft enough to mash. Strain the cooked fruit
through cheese-cloth.
Put 1 teaspoonful of the extracted fruit juice in a saucer, add an equal
quantity of alcohol. [Footnote 126: Either grain (ethyl), wood (methyl), or
denatured alcohol may be used. Both wood and denatured alcohol are
poisonous. If they are used for testing, they should be handled and
stored away with caution.] Mix by gently rotating the saucer. Let the
mixture stand for 5 minutes. Then examine. What change has taken place in
the fruit juice?
The formation of a solid mass in the mixture of fruit juice and alcohol
which has stood for 5 minutes indicates that the fruit juice contains
pectin,--a vegetable gelatine.
EXPERIMENT 95: PECTIN IN THE INNER PORTION OF ORANGE OR LEMON PEEL.--Cut
away the yellow portion from orange or lemon rind. Cut or chop the white
portion of the rind in small pieces. Cover with water and soak several
hours or overnight. Then cook slowly for 1/2 hour. Strain and set aside to
cool. To 1 teaspoonful of this liquid add an equal quantity of alcohol,
and proceed as in Experiment 94. Does the lemon or orange rind contain
pectin?
THE PRINCIPLE OF JELLY MAKING.--When the juices of certain fruits are
extracted and cooked with sugar, the mixture stiffens when cool. This
property of stiffening is due to the presence in fruit of two materials,--
a certain carbohydrate, called pectin, and an acid. Pectin is like
starch in that it stiffens when cold; but like sugar, in that it is
soluble. Not all fruits contain pectin.
Jelly is most easily prepared from fruits which are rich in pectin and
contain some acid. Unless pectin is contained in the fruit, the addition
of sugar to fruit juice will not cause the juice to jelly. But jelly may
be made from a fruit lacking in pectin, if it is combined with a fruit
rich in pectin.
Certain fruits contain pectin, but are lacking in acid, hence are not good
for jelly making. These fruits can be used for jelly, however, if acid is
added.
SELECTION OF FRUITS FOR JELLY MAKING.--For jelly making, choose fruits
which contain considerable pectin and some acid. The fruits should be
fresh and not over-ripe. Some "green" fruits make fine jelly. Currant,
crabapple, grape, apple, and plum are good jelly-making fruits.
If it is desirable to use a fruit containing little pectin, as
strawberries, add a fruit rich in pectin, as currants. If about 10 per
cent of the fruit which contain much pectin is added to the other fruit,
the flavor of the foundation fruit is not much altered.
If it is desired to use a fruit containing pectin but deficient in acid,
as sweet apple and quince, add tartaric or citric acid. Since the acidity
of fruits varies, no definite quantity of acid can be stated. It has been
suggested [Footnote 127: See University of Illinois Bulletin, "Principles
of Jelly Making," p. 249.] that enough acid should be added to make the
fruit juice about as acid to taste as good tart apples. At least one
teaspoonful of acid is required for one quart of fruit juice. Dissolve the
acid in the fruit juice, then taste the mixture. If necessary, add more
acid to produce the acidity indicated above. Jelly may be prepared from
strawberries, peaches, and pears by the addition of these acids, but the
flavor is somewhat impaired.
The suggestion has been made also [Footnote 128: Idem, p. 25.] that
the inner white portion of lemon or orange peel be used as a source of
pectin with fruit deficient in pectin. Remove the yellow portion of the
rind, put the white portion through a food chopper, and soak in water for
several hours or overnight. Then cook slowly for several hours. Strain out
the solid portion. Add the liquid to the fruit juice deficient in pectin
and use for jelly making. The rind of lemons and oranges may be dried for
use in jelly making. When desired for use, soak and cook as directed
above.
GENERAL METHOD OF JELLY MAKING
Wash and pick over the fruit; remove the stems, but use the skin and seeds
and thus retain as much of the fruit as possible. The skin of fruit
usually adds color to jelly. If large fruit is used, cut it in pieces.
Cook the fruit slowly in water. Use very little water for juicy fruits,
such as currants and raspberries,--1 cupful of water to 4 or 5 quarts
of fruit. Crush the fruits during cooking.
To cook large fruits requires water. A general proportion is half as
much water, by measure, as prepared fruit. A little less water may be
used for peaches and plums and a little more for winter apples. A fair
estimate is 3 quarts of strained juice from 8 quarts of fruit and 4 quarts
of water. If the quantity of juice is greater than this, it should be
boiled down to 3 quarts before adding the sugar.
When the fruit is cooked until it is very soft, it is ready for straining.
For straining, make a bag of double cheesecloth or flannel. Wring the
jelly bag out of hot water and suspend it from a strong support. Pour the
cooked fruit into the bag and let the juice drip into a bowl. If
transparent jelly is desired, do not press the juice through the bag; let
the juice drip for several hours or overnight.
Measure the clear fruit juice and heat it. The time of cooking depends
upon the per cent of pectin and the acidity of the juice; the more pectin
and acid, the less the time of cooking. The time varies from 8 to 30
minutes. Skim the juice when necessary. While the juice is cooking,
measure three fourths as much sugar [Footnote 129: The quantity of
sugar used in jelly making depends upon the quantity of pectin in fruit
juice,--the more pectin, the more sugar. A most satisfactory method of
determining the quantity of pectin and consequently the quantity of sugar
to use with fruit juice is suggested by the Bulletin of the National War
Garden Commission. The test follows: To a tablespoonful of fruit juice
which has been boiled and cooled, add 1 tablespoonful of alcohol (see
footnote 126.). Mix by gently rotating and then let stand. If a solid mass
forms, use equal parts of fruit juice and sugar. If 2 or 3 masses
form, use 2/3 to 3/4 as much sugar as juice. If several small solid
particles form, use 1/2 as much sugar as juice. If no solid
particles form, the fruit juice should be enriched by the addition of some
pectin-rich fruit juice.] as fruit juice and heat the sugar. For
currants and green or under-ripe grapes, use equal quantities of sugar and
fruit juice. Add the hot sugar to the boiling sirup and cook. The
following are tests for sufficient cooking of jelly.
(a) Coats the spoon.
(b) Falls from the spoon in heavy drops. [Footnote 130: Two drops
forming side by side along the edge of the spoon has been found to be a
reliable test.]
(c) Stiffens when dropped on a cold dish and allowed to cool.
The first two tests are more satisfactory than the last, since the cooking
process may be carried too far while the "test-jelly" is cooling.
Seal as Jam or shred paraffin and place it in the bottom of sterilized
jelly glasses. Pour the hot jelly into the glasses and set aside to
stiffen. Then cover and store. It is well to store jelly in a cool, dry,
and dark place. The color of fruit sometimes fades when kept in a light
place.
Long cooking of pectin changes it into substances which do not have the
property of jellying, hence, make jelly in as short a time as possible.
The purpose of heating the sugar is to hasten the process of jelly making.
The addition of cold sugar would cool the mixture and thus prolong the
process.
The addition of too much sugar is often the cause of unsuccessful jelly
making. Crystallization of the sugar from the jelly may result from an
excess of sugar.
The fruit pulp left in the jelly bag should be utilized. Marmalade
may be made from it, or more jelly can be prepared from it. To accomplish
the latter, add water to the fruit pulp (enough to cover), mix, and heat
slowly until the boiling point is reached. Strain and prepare jelly from
the juice. However, more cooking of the juice before the sugar is added is
required for the second extraction, since the juice contains so much
water. The juice extracted for a third time from most fruits will contain
enough pectin for jelly making. It has been found that more desirable
jelly can be obtained by this method than by pressing the juice from the
bag and thus obtaining what is termed "second quality" jelly.
FRUIT JUICES WITHOUT SUGAR.--Extract the juice from fruit as directed in
General Method of Jelly Making. Do not add sugar to the juice. Can
it as directed in (a) or (b).
(a) Reheat until the boiling temperature is reached, then pour into
sterilized jars. Fill to overflowing and seal.
(b) Place the juice in sterilized jars. Partially seal and place in
a water bath having the water reach the neck of the jar. Let it cook at a
simmering temperature from 20 to 30 minutes. Remove from the water bath,
and seal securely.
In the winter time or when desired for use, this fruit juice may be made
into jelly as directed in General Method of Jelly Making, or it may
be sweetened, diluted if necessary, and used as a beverage. This method of
preserving fruit juice is especially desirable when there is a scarcity of
sugar.
[Illustration: FIGURE 92--THE COMPOSITION OF FRUITS AND FRUIT PRODUCTS.
(Revised edition.)]
QUESTIONS
Note the difference in the quantity of carbohydrates in Canned Fruit and
Fruit Jelly (see Figure 92). What kind of carbohydrate is present in
greatest quantity in these foods?
To what is the difference in flavor of Canned Fruit and Fruit Jelly
largely due?
What is the chief difference in the processes of jam making and jelly
making?
What is the result if too much sugar is used in jelly making?
What is the result if jelly is cooked too long?
Note the difference in the methods of sealing jams and jellies. Explain.
LESSON CLXX
PROCESSING WITH VINEGAR AND SPICES--RELISHES
SPICES AND VINEGAR ARE PRESERVATIVES OF FOODS. Not all spices, however,
have equal preservative power. It has been found that cinnamon and cloves
aid in food preservation, but that pepper and ginger have very little, if
any, preservative power. In the lesson on Flavoring Materials: Food
Adjuncts, it was mentioned that spices and condiments should be used
sparingly in the diet, hence spiced fruits and pickles should have only
occasional use. There is no doubt that lemon juice or other tart fruit
juices are better sources of acid-satisfying materials than vinegar.
SPICED PEARS
1/2 peck pears
3 pounds sugar
1 pint vinegar
1/2 ounce ginger root
Rind of 1/2 lemon
Whole allspice
Stick cinnamon
Whole cloves
Cut the pears in halves, remove the seeds, and pare. Into each piece of
pear stick two or three cloves. Make a sirup of the vinegar and sugar.
Divide the cinnamon, allspice, and ginger into two parts, tie in cheese-
cloth bags, and add to the sirup. When the sirup begins to simmer, add the
pears and lemon rind; bring to the boiling point, remove from the fire,
and turn into a stone jar. Cover and stand in a cool place overnight. Next
day bring the mixture to the boiling point, again place in the stone jar
and stand overnight. The following day heat as before. Do this for five
consecutive days. The last day, remove the fruit from the sirup, heat the
sirup and evaporate it until there is just enough to cover the fruit. Add
the fruit to the hot sirup, heat to the boiling point, then put in stone
or glass jars or tumblers.
The pears may be finished in one day as follows: Cook the fruit until
tender, then remove it, evaporate the sirup, add the fruit, reheat again,
and finish as above. Fruit prepared by the first method has a finer
flavor.
TOMATO CATSUP
12 ripe tomatoes
2 large onions
2 green peppers
2 tablespoonfuls salt
4 tablespoonfuls brown sugar
2 tablespoonfuls ginger
1 tablespoonful cinnamon
1 tablespoonful mustard
1 nutmeg grated
1 pint vinegar
Peel the tomatoes and onions. Chop the onions and peppers fine. Cook all
the ingredients together for 3 hours, or until soft and broken. Stir
frequently. Bottle and seal while hot. The mixture may be strained before
bottling.
CELERY SAUCE
20 large ripe tomatoes
6 large onions
4 large stalks celery
3/4 cupful sugar
1 large red pepper
4 tablespoonfuls salt
2 cupfuls vinegar
Chop the vegetables, add the salt and vinegar, and cook for 2 hours. Then
add the sugar. Allow it to reach the boiling point again. Turn into
sterilized bottles or jars, and seal.
OIL PICKLES
2 dozen small cucumbers
2 dozen small onions
1/2 cupful olive oil
1/4 cupful sugar
1 pint vinegar
1/3 cupful salt
1/4 cupful mustard seed
1 pint vinegar
1 teaspoonful celery seed
Scrub the cucumbers. Cut them (without paring) into thin slices. Wash and
cut the onions into thin slices. Mix the salt with these vegetables (to
extract moisture), and let the mixture stand over night. Then drain the
moisture from the vegetables so that the vinegar may not be diluted.
Mix the remaining ingredients. Pour the mixture over the onions and
cucumbers. Mix well, cover, and set aside for a few hours. Then pour into
sterilized jars. Fill the jar with liquid. (If necessary, more vinegar may
be used.) To drive out the air, place the jars (with covers loosely
adjusted) in a water bath at simmering temperature (180 degrees F.) and
heat at this temperature for 15 minutes. Remove from the water bath and
seal.
TO SEAL BOTTLES.--Melt together, over hot water, equal parts of
shoemaker's wax and resin. When liquefied, dip the tops of corked bottles
into it. Corks in bottles may be dipped also in hot paraffin. Dip several
times.
QUESTIONS
What is the objection to excessive use of spiced foods?
Name some substitutes for pickles. Why is an excessive or continuous use
of pickles objectionable in diet?
LESSON CLXXI
CANNED VEGETABLES
MICROORGANISMS IN THE SPORE FORM.--Many microorganisms are destroyed by
heating them for a few minutes to boiling temperature. However, some
microorganisms have a peculiar power of retaining life under most adverse
conditions. When subjected to extreme heat or cold, intense drying, or
when there is lack of food, certain microorganisms assume a spore form,
i.e. they cease growing and reproducing, and are able to undergo
conditions which would readily kill microorganisms in the active form.
Some microorganisms in the spore form are able to resist the temperature
of boiling water for an hour or longer. Then as soon as the adverse
conditions mentioned above are removed, the microorganisms assume active
form and begin to grow and reproduce. In the growing state, their
destruction is not so difficult.
Some of the microorganisms in certain foods, especially vegetables and
fruits grown in a dry season, are capable of spore formation. When
microorganisms in spore form do exist in foods that are to be canned, or
the microorganisms change into spore form during the canning process, the
microorganisms may not be destroyed by the time the ordinary process of
canning is completed. If such is the case, when the canned foods are
cooled and the conditions are favorable for growth, the microorganisms
assume active form, begin to grow, and cause the decomposition of food.
Twenty-four hours is sufficient time for the microorganisms to change from
the spore to the active form. Hence the canned foods must be heated again,
if they are to be preserved. For foods difficult to process (for the
reason given above) processing should be carried on for three successive
days. This is called intermittent processing.
Destruction of microorganisms in the spore form can be accomplished in a
short time by subjecting them to very intense heat. In canning factories
this is done by processing at a temperature higher than that of boiling
water. In the home this may be accomplished by processing in the pressure
cooker. According to one authority processing intermittently, i.e.
on three successive days, does not insure satisfactory processing of
materials containing spores.
SINGLE PERIOD AND INTERMITTENT PROCESSING.--The acid of tomatoes and
fruits aids in the destruction of microorganisms. Hence intermittent
processing is unnecessary for these. Processing tomatoes and fruits in a
hot water bath for one period has proved very satisfactory and certain.
There is some question, however, regarding the safety of canning all
vegetables by one period of processing in the water bath at 212 degrees
F., especially in regions where botulism is known to occur and where
Foods cannot be stored in a cool place. In Farmers' Bulletin 1211,
"Home Canning of Fruits and Vegetables," revised August, 1922, one period
of processing in the water bath at 212 degrees F. is not advised in
climates where the storage conditions are trying for the following
vegetables: corn, beans, asparagus, okra, spinach and other greens, and
peas (especially if at all mature). For processing these vegetables, a
higher temperature than that obtained in the boiling water bath is
recommended. Processing at a high temperature (from 228 degrees F. to 250
degrees F.) can be accomplished conveniently by means of a pressure
cooker. This is especially recommended for vegetable canning in high
altitudes and in localities where botulism has occurred.
It is thought that in some places the above mentioned vegetables may be
processed intermittently with safety. For vegetables difficult to
can, pint jars only are recommended for both intermittent and single
period processing in the water bath. Heat penetrates more rapidly to the
center of the small jars than to the center of the large jars.
SELECTION AND PREPARATION OF VEGETABLES AND CANNING.--Young vegetables,
especially those that have grown quickly, are most desirable for canning.
If possible, vegetables, especially corn, should be canned immediately
after picking.
Vegetables for canning should be thoroughly washed, pared, scraped, or cut
into pieces in the same manner as when they are cooked and served
immediately. If the vegetables vary in size, it is well to sort them and
fill jars with those of uniform size. If there is much difference in
ripeness, sort the mature and young vegetables.
METHOD OF CANNING VEGETABLES.--The method of canning vegetables for a
single period does not differ greatly from the method of canning
fruits. The chief difference is that jars containing fruit are filled with
sirup, while those holding vegetables are filled with water and salt is
added. Blanch and cold-dip vegetables as directed previously, for the
length of time given. Greens and vegetables of delicate flavor are
blanched most successfully by steaming either in a colander placed over
boiling water or in a steamer. (Steaming greens prevents the escape of
volatile oils and other materials.) Pack the vegetables in jars to within
1/2 inch of the top. It is well not to pack spinach and other greens too
solidly in jars. Since lima beans, corn, and peas swell during processing,
they should be packed only to about 1 inch of the top of the jar. To each
jar add salt,--1 teaspoonful to each quart jar. Fill each jar to 1/2 inch
of the top with boiling water. Put a new rubber on the jar, partly seal
the cover, and proceed as directed for fruit (see Table below for the
length of time for processing).
When vegetables are processed intermittently, jars with glass tops
and spring clamps are recommended. In processing vegetables for three
successive periods, the same method of processing and sealing is followed
as for the single period. At the beginning of the second and third
periods, raise the clamps of the jars to allow for expansion, then fasten
the clamps at the close of processing period (see Table for the length of
time of processing on each of the three successive days).
FOOD PRESERVATION
TABLE FOR CANNING FRESH, SOUND, AND FIRM VEGETABLES BY ONE PERIOD OF
PROCESSING [Footnote 131: Adapted from Farmers' Bulletin 1211. Revised
August, 1922.]
TIME OF PROCESSING
TIME OF
VEGETABLE BLANCHING OR (a) (b) Steam Pressure
Water (Pressure Cooker)
COOKING Bath at (1) 5lb (2) 10lb (3) 15lb
212 deg. F. 228 deg. F. 240 deg. F. 250 deg. F.
Minutes Hours Minutes Minutes Minutes
Asparagus 4 - - 30 to 40
Corn 1 to 5 - - 90 60 to 90
Lima beans 3 to 5 - - 45 to 60
Okra 6 to 8 - - 30
Peas 3 to 8 - - 40 to 50
Spinach 4 in water or
15 in steam - - 90 35
String beans. 3 to 5 - - 40 to 50
Tomatoes 1 to 1 1/2 to
loosen skins 1/2 15 10
[Footnote for Asparagus: Scrape off tough outer skin of asparagus.
Tie into bundles for blanching. Blanch tough ends 2 minutes and entire
bundle 2 minutes longer.]
[Footnote for Corn: Blanch corn on the cob, then cold dip and cut
from the cob. For each pint jar, use 1 pint of cut corn, 1 cupful boiling
water, and 1/2 tea-spoonful each of salt and sugar. Cook the mixture in
a saucepan until it boils and pour immediately into a hot, sterilized
jar.]
[Footnote for Okra: Cold dip okra in salt water (1
tablespoonful salt to 1 quart water).]
[Footnote for Spinach: To loosen grit, cover spinach with scalding
water, let stand 1 or 2 minutes. Then wash in several cold waters. Do not
cold dip after blanching.]
[Footnote for Tomatoes: Pack tomatoes whole in jars, then fill the
jars with cooked and strained tomato pulp. Tomatoes cut into pieces may be
packed closely in jars. When this is done, no liquid need be added.]
NOTE.--Processing in the hot water bath is not advised for non-acid
vegetables such as asparagus, corn, lima beans, okra, peas, spinach, and
string beans.
Count time of processing in a water bath after the water boils.
When two different times of processing are given, use the longer time for
quart glass jars, the shorter time for tin cans.
If the jar is packed tightly, increase the time of processing.
For altitudes higher than 1000 feet, increase the time of processing 10
per cent for each additional 1000 feet. For very high altitudes, the
pressure cooker rather than the hot water bath should be used.
TIME TABLE FOR CANNING VEGETABLES BY INTERMITTENT PROCESSING [Footnote
132: See statements previously]
VEGETABLE TIME OF TIME OF PROCESSING IN WATER BATH
BLANCHING AT 212 F. 12 TO 18 HOUR
INTERVALS BETWEEN PERIODS
(a) First Day (b) Second
and Third Day
Asparagus 10 to 15 60 60
Corn 5 to 10 90 90
Lima Beans 3 to 5 90 90
Peas 5 90 90
String Beans 3 to 5 90 90
[Footnote 133: (For Asparagus, Corn, and Lima Beans) Process in pint
jars only. See footnotes for Asparagus and Okra, above.]
USE OF CANNED VEGETABLES.--Open the can and if it is tin, empty its
contents at once. If the vegetable is surrounded by liquid, use the water
in cooking the vegetable, as it contains valuable materials. There are
some who contend, however, that the flavor of certain vegetables such as
peas and string beans is improved if the vegetable water is drained from
them and they are cooked in fresh water. If this is done, the vegetable
water should not be wasted. It should be used in making soup or sauce. If
possible, let the vegetable stand exposed to the air for an hour or
longer.
If the vegetable is to be served plain, turn into a saucepan. Cook in its
own liquor at boiling temperature, for at least 30 minutes. (Cooking at
boiling temperature for this length of time is advised to remove any
possible danger of botulism.) When cooked, the liquid should be almost
entirely evaporated. Add butter, salt, and, if desired, a very little
sugar, and serve hot.
A White Sauce may also be used with a vegetable that has been heated as
above.
QUESTIONS
Explain why vegetables (except tomatoes) are more difficult to can
successfully than fruits.
What foodstuffs does the water in which vegetables are canned contain?
From this explain why the water should not be drained from vegetables when
removing them from the cans.
What is the purpose of cooking canned vegetables at boiling temperature?
LESSON CLXXII
DRIED VEGETABLES
ADVANTAGES OF DRYING FOODS.--While preserving foods by drying does not
take the place of canning foods and storing them in jars or cans, it has
certain advantages, viz.:
1. Little storage space is required for dried foods.
2. Dried foods can be stored in containers that cannot be used for
canning.
When foods are dried, they may be reduced in bulk as much as 90 per cent;
for example, 10 pounds of fresh food may be reduced to 1 pound of dried
food. By this reduction no food value is lost, and the flavor is not
greatly changed.
Dried foods may be stored in paper bags and boxes which are much less
expensive containers than glass jars or tin cans. Hence if space is
limited and glass or tin containers are difficult to secure or are
expensive, drying may prove a very satisfactory method of preserving food.
METHODS OF DRYING AND DRIERS.--Food may be dried by:
1. Sun.
2. Steam (placing food on a specially constructed tray (see Figure 93)
which is heated with steam).
3. Stove or oven drying (placing food above a stove or in the oven).
4. Fan drying (placing an electric fan near the food).
A combination of these methods, especially the two latter, is often used
in drying foods.
Plates or dishes may serve as driers when the drying is done in the oven.
Trays for drying may be constructed at home or they may be purchased. Most
of them consist of a wood or metal frame over which wire netting is
tacked. Single trays or a series of trays one placed above the other may
serve as driers. When drying is accomplished by heat from a stove, the
drier is hung over a stove or it rests on the top of the stove. In the
latter case, it is necessary that the frame of the tray be constructed so
that the bottom tray does not rest directly on the stove. In case the
drying is done over a kerosene stove, the bottom of the tray must be of
tin or galvanized iron to protect the food from kerosene fumes. The lowest
tray must be placed at least 4 inches above the metal bottom.
SELECTION AND PREPARATION OF VEGETABLES FOR DRYING.--To secure the best
results, select mature but fresh vegetables. They should be in good
condition, free from blemish.
Certain foods, such as berries, cherries, peas, lima and shell beans, are
dried whole. Most vegetables should be cut into slices from 1/8 to 1/4
inch in thickness. The slicing may be done with a paring or kitchen knife,
or it may be done by means of a slaw-cutter or a rotary chopper. Foods are
sometimes cut into pieces for drying by means of the food chopper. It is
necessary that all knives and cutting devices be clean. There should be no
discoloration of the vegetable from the cutting utensil. It has been found
advisable to blanch most vegetables before drying. The method of blanching
given previously can be used in drying vegetables as well as canning them.
Foods are not cold-dipped, however, after blanching when they are to be
dried. Fruits are usually not blanched before drying.
FOOD PRESERVATION
METHOD OF DRYING FOODS.--Place the prepared food on drying trays. Unless
the drying is done in the oven, cover the food with cheese-cloth. If
possible, tack the cloth to the frame so that no dust or insects can come
in contact with the food. Stir or turn foods once or twice a day while
they are drying. This is especially necessary when foods are dried in the
sun.
If the food is to be dried in the sun, place the tray containing
the food in the sun, where there is a breeze. If it rains, take the trays
indoors. Also bring the trays indoors just before sunset.
If food is to be dried by means of steam, a special device is
needed (see Figure 93). The device consists of a large pan for holding
water and a hollow tray. The under surface of the tray has an opening
about the size of the diameter of the pan. To this opening is fastened a
collar which fits snugly into the pan. The pan filled with water is placed
over a burner. When the water boils, the steam rises and fills the hollow
tray and escapes by means of the small pipe in the upper surface of the
tray. The food is placed on the upper surface and i
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