UC-NRLF
PROVINCE OF BRITISH COLUMBIA
DEPARTMENT OF AGRICULTURE
(WOMEN'S INSTITUTES).
BULLETIN No. 37.
THE PRESERVATION OF FOOD
MISS ALICE RAVENHILL,
Fellow of the Royal Sanitary Institute, etc., etc.
THE GOVERNMENT OF
THE PROVINCE OF BRITISH CCUIMBIfl.
PRINTED BY A VTHORITY OF
THE LEGISLATIVE ASSEMBLY OF BRITISH COLUMBIA.
VICTORIA, B.C. :
Printed by WILLIAM H. CULLIN, Printer to the King's Most Excellent Mnjosl.v.
1912.
DEPARTMENT OF AGRICULTURE,
VICTORIA, B.C., 26th February, 1912.
The Honourable Price Ellison,
Minister of Agriculture :
SIR, I have the honour to submit herewith Bulletin No. 37,
entitled "The Preservation of Food," prepared on behalf of the
members of the Women's Institutes.
I have the honour to be,
Sir,
Your obedient servant,
WM. E. SCOTT,
Deputy Minister of Agriculture,
Superintendent of Institutes.
THE PRESERVATION OF FOOD.
~VT7~HOLESOME, suitable, and varied food is essential to efficient life. Imperfect
T T nutrition from defective, not deficient, food is the unsuspected source of a
large amount of ill-health, unhappiness, and crime.
DESIRE FOR FOOD A FUNDAMENTAL INSTINCT.
To desire and seek food is an instinct common to every type of life. The kind of
nourishment necessary to maintain life in its countless forms is, of course, widely
varied. The dietary of plants (gases from the atmosphere, salts from the soil, moisture
from dew and rain) is obviously unsuited to insects, for instance, or fish. The ox is a
strict vegetarian ; the cat is an equally consistent consumer of animal food. With few
exceptions, notably the domesticated pig and dog, the diet of all types of life other than
human is monotonous ; limited to a few kinds of food, of one class ; in the absence of
which the creature dies, being unable to adapt itself to any decided change in its food.
On the other hand,
MANKIND THRIVES ON VARIED FORMS OF FOOD
and benefits by change of diet. Indeed, if human life is to be vigorous, efficient, and
prolonged, a combination of animal, vegetable, and mineral foodstuffs is essential.
Efforts have been made by individuals, in the interests of convenience or economy,
to limit their diet to bread or oatmeal over a given period, or otherwise to restrict their
daily meals to one or two of the simplest forms in which food can be obtained eggs,
for instance ; but the end has been invariably disaster. Appetite fails, energy suffers,
illness, even death, results.
Some of the reasons why variety of food is so important to human health will be
supplied in the bulletin on " Food and Diet." The point which now claims our atten-
tion is this : If a sufficient quantity of wholesome, suitable, and varied food is essential
to well-being, upon what does the supply depend ?
THREE FACTORS IN HEALTHFUL DIET.
Briefly, it depends upon three factors :
(1.) Ability to produce, purchase, or otherwise procure the food material necessary :
(2.) Knowledge to guide the selection, preparation, and service of this material :
(3.) Intelligence to direct and control the amount and character of the food pre-
pared.
At first sight factor (1) might be dismissed as dependent upon income only. A little
consideration, however, will suffice to show that it underlies the whole question of food,
preservation. Some kinds of food can be grown only in certain latitudes ; as, for
example, wheat and corn, which must be transported long distances to millions of
consumers. Most fruits and vegetables can only ripen in certain climates, and unless
preserved in season would even then be enjoyed over a very short period of each year ;
while to thousands their beneficial influences would be entirely denied.
Again, the population of the world is either closely concentrated in huge cities or
widely scattered over districts often remote from markets. In either case people depend
upon other sources than their own produce for a part at least of their food-supply.
Factor (2) calls for that knowledge which raises housekeeping to the rank of a
profession. Training is necessary to understand why food which is wholesome in winter
may be unwholesome in summer. Sausages, for instance, are always suspicious when
the weather is warm, owing to the favourable soil they provide for the multiplication
of putrefactive bacteria ; whereas this risk is practically absent when there are several
degrees of frost, as a low temperature impedes the growth of micro-organisms.
Again, instruction is needful to show why food which is suitable to the hard
outdoor worker, such as pork, molasses and beans, is entirely unsuited to the city
clerk, who passes his time in an overheated office ; for whose requirements a lunch of
fruit and rice-milk, or a lightly cooked egg with bread and butter, would amply
suffice.
Knowledge of the process of digestion is required before the evils of a monotonous
diet are understood.
Food may in itself be nutritious, abundant, and well cooked ; yet the consumer
will, sooner or later, lose all relish for his meals and fall a victim to dyspepsia in one
of its myriad forms, unless there be variety of flavour and form.
SOME RESULTS OF MONOTONOUS FOOD.
The craving for a fillip to the palate is one dominant cause of drunkenness. An
exaggerated consumption of pickles and sauces, of candies or of fruit, are frequent
indications of this failure on the part of the cook to vary the character of her dishes.
The craving for change has led even to the voluntary taking of nauseous drugs, which
occurred so conspicuously at an industrial school for boys that an investigation as to
the cause was undertaken. The unnatural taste was traced to the deadly monotony of
the dietary, which was designed to fulfil all the needs of growing lads, except this
important feature of judiciously varied flavour.
not in the use of artificial means, such as highly flavoured sauces, vinegar, or pickles,
but by the employment of vegetables, herbs, small quantities of different spices, slight
changes in the proportions of perhaps the same ingredients, or even in presenting the
same dish baked one day, stewed or steamed another, and so on.
ASSOCIATION BETWEEN FLAVOUR AND DIGESTION.
Man}' housewives have noted the brightening eyes and smiles of pleasure associated
with the appearance on their tables of an unfamiliar or a favourite dish ; but few cooks
seem aware that the watering mouths and sniffs of satisfaction, excited by savoury
odours from the kitchen, are so many aids to digestion and promoters of efficient work
at home and at school.
SOME REASONS WHY MEALS ARE MONOTONOUS.
The thoughtful mother, permeated with the bracing spirit of Puritanism, dreads
to foster greediness by a too frequent tickling of the family palate. The thoughtless
housekeeper skimps her kitchen-work, from failure to realize its bearing on health and
happiness. The tired woman shirks the extra trouble occasioned by consultation with
her cookery-book before she plans the day's meals.
FOOD-PRESERVATION AN IMPORTANT FACTOR IN WHOLESOME
VARIETY.
The country housewife has acquired the habit of preserving certain foodstuffs,
plentiful at one season of the year, in order to make good inconvenient deficiencies at
Another berries, for instance, or pork. The town housekeeper is tempted, in spite of
herself, to introduce some variety into her bill of fare, owing to the produce of the
whole world being displayed in most attractive forms before her eyes, at her favourite
store.
Dried and canned foods maintain the health of dwellers in the Yukon, or of arctic
or tropical explorers, and thus contribute to the world's progress. The lives of infants
and invalids may hang upon this means of securing for them suitable nutrition under
adverse conditions of climate, temperature, or disease.
(Fro. 1.)
Specimens of canned foods in
common use.
Figs. (1), (2), (3), (4), (5), (6), (9). and (10) are reproduced, by kind permission of Messrs. Sidgwiclt &
Jackson, London, from "Household Foes," by Alice Kavenhill.
Some form of preservation is necessary for foodstuffs, such as meat, vegetables,
eggs, or fish, which constantly have to be transported long distances ; half across the
world, indeed, to meet the needs of some crowded community unable to supply its
enormous demands locally. The food-supply of the capital city of our great Empire,
with its seven million inhabitants, is drawn from all over the globe. To trace the
sources of the ingredients in our own Christmas pudding will be found to constitute
quite a fine exercise in geography !
AN IMPORTANT POINT IN FOOD-PRESERVATION.
Too much insistence cannot be laid upon this point in connection with the wholesome
preservation of food. It must not be subjected to any treatment which may interfere
in the slightest degree with the process of digestion or which will disguise the fact if
decay has already set in. Preferably, too, the appearance of the food should not be
affected, though this is of minor importance.
To discover how far these points are taken into consideration, it will be well
briefly to review the
METHODS OF FOOD-PRESERVATION IN GENERAL USE.
These might be divided into two sections :
(1.) Commercial methods of food-preservation, carried out on a large scale, of
which the products are for sale :
(2.) Domestic methods, carried on in the home, for family use only.
But so many of the processes employed are common to factory and home, varying
only in the quantities of food materials handled, that it is possible to pass the methods
and their reasons in review without such distinction.
Before doing so, however, it is important to have a clear idea of
WHAT DECAY IS.
For the whole object of the preservation of food is to postpone what we call decay.
Those changes in food which alter its character and often affect its appearance, which
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usually influence its flavour and always make it unwholesome, occasionally even
poisonous, are all included under the general term decay.
Mouldy cheese, sour milk, tainted meat, strong butter, stale fish, decayed fruit,
musty flour, bad eggs, and fermented jam have one and all suffered these changes,
owing to the invasion of their substance by the invisible seeds of germs, yeasts, and
moulds.
WHY DECAY SPREADS SO RAPIDLY.
These micro-organisms multiply with extraordinary rapidity when the conditions
of food, of temperature, and of moisture are favourable to their growth. It is said
that one micro-organism, in itself too minute to be detected apart from its fellows, even
under a powerful microscope, might fill the ocean solid with its offspring in five days,
were their development unchecked.
Specimens of moulds which attack food : life-size and also highly magnified
to show mode of growth and method of seed-distribution.
When we bear in mind that each of these microscopic atoms of life can become
responsible for seventeen million descendants in twenty-four hours, it is a cause for
thankfulness that the delicacy of their organization and the fastidiousness of their
tastes never permit the realization of these risks, or they would rapidly oust us from
the world.
MICRO-ORGANISMS, GOOD AND BAD.
As a matter of fact, man can only continue to inhabit the earth because of the
valuable assistance he receives from these very micro-organisms, who serve his interests
faithfully as scavengers when they destroy and remove his refuse, or as labourers when
they fertilize his fields and gardens, or as chemists when they heat his silo.
Vinegar, tobacco, linen, and cheese are but a few useful products which we owe to
different families of these germs. But, like all good things, they must be kept in their
right place, and that place is not in kitchen, larder, or store-room.
WHAT IS FERMENTATION?
Mention of one product of the micro-organisms of decay must not be omitted. Certain
of these germs, while not actually themselves injurious to the food on which or within
which they find a resting-place, yet render that food unwholesome by the results of
their presence. Just as much as a number of people occupying a room for some time
render the atmosphere of that room unpleasant and unwholesome ; or just as much as a
garment worn next the skin becomes dirty from the perspiration with which it is in
contact, so these minute living things bring about changes in their surroundings by their
active life.
The substances which bring about these changes are called ferment*, and their
results are called fermentation*. If these fermentations occur in foodstuffs, their
character and quality are so changed for the worse (with few exceptions) that they are
quite unfit for human food.
It may be argued that wine and beer are both the products of fermentation, but
that when taken in moderation they are wholesome drinks. In both these cases the
process of fermentation is watched ; it proceeds under carefully supervised conditions,
and is checked at a definite point and moment.
Besides which there are countless varieties of these micro-organisms some of which
cause fermentations useful to man, while others are dangerous to his health.
One property possessed by these ferments is the source of considerable trouble to
the housewife, and that is their capacity for producing effects out of all proportion to
the amount of ferment present. It is not the quantity of ferment produced in a joint
of meat by these mischievous germs which taints the whole ; the widespread chemical
changes, which render it unfit for food, may be brought about by a microscopic particle
of the offending substance.
MOULDS AND YEASTS AS AGENTS OF DECAY.
Moulds also bear their part in causing food to be unpalatable, if not unwholesome ,
and yeast-plants grow freely in thin syrups, for instance ; hence the fermentation which
sometimes takes place in carelessly bottled fruit.
Thus decay in any of its varied forms may actually render food poisonous ; it
certainly makes it less wholesome ; it spoils its appearance ; and assuredly it leads to
much waste of what should be good nutritious material.
(Fio. 3.)
A dirty practice, which conduces to
the decay of food in households where
it is permitted.
SUMMARY.
(1.) Decay is the work of living organisms or of the results of their active presence
in food substances.
(2.) Necessary to their activity is suitable food, suitable temperature, and sufficient
moisture.
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(3.) These requirements are easily satisfied in food factory, market, shop, dairy,
kitchen, larder, and store-room, unless constant and intelligent care and suitable
precautions be exercised.
It is therefore evident that in
THE PREVENTION OF DECAY
is found the means for the preservation of food. Housekeeper and food-purveyor alike
are confronted by the problem how to prevent the access to foodstuffs of these germs,
yeasts, and moulds, of which decay is the product.
THE PRESERVATION OF FOOD.
Attempts to solve this problem have been made along the following lines :
(a. ) By so treating food that it becomes unfavourable to their growth and unsuitable
to their nutrition :
(b.) By submitting food to conditions which will destroy these micro-organisms, if
there is reason to believe they are present :
(c.) By protecting and sheltering food from their attacks.
(a.) MEANS BY WHICH FOOD is RENDERED UNSUITABLE FOR AND UNPALATABLE TO
THE SOURCES OF DECAY.
(1.) Food can be smoked (i.e., exposed for a longer or a shorter time to the vapour
of burning wood or peat). The results of this treatment are threefold :
(i. ) The meat or fish becomes saturated with certain acid antiseptics, such as creosote,
which are produced by the combustion of wood, peat, and coal. It is thereby
rendered unpalatable to the germs of decay :
(ii.) The foodstuffs become too dry to supply the amount of moisture necessary to
germ -growth :
(iii.) The smoke also destroys the micro-organisms, if present, though here
Two Cautions are necessary.
Exposure to smoke will not affect the poisonous products of these putrefactive
germs if decay has already set in ; neither does it destroy parasites. Consequently,
smoked but uncooked " measly :> pork or meat otherwise unsound cannot be made fit for
food by this treatment ; neither should the consumption of smoked but uncooked
sausages ever be permitted. In Germany it is illegal.
(FIG. 4.)
How flics infect food with seeds of decay and also with the germs of
disease ; consumption, for instance, or typhoid fever.
(2.) Food can be dried by Ej-poxure to Sun, Air, or Artificial Heat. This is prob-
ably the oldest of all methods of food-preservation, and is still in general use all over
the world. Uncivilized man still dries his strips of meat or fish in the sun and wind ;
civilized man more often relies upon this raeaiis of removing moisture to preserve
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vegetables and fruits, such as hops, herbs, peaches, grapes (raisins and currants, for
example), or the peel of oranges and lemons. The result is to render the substance of the
food too dry to allow any form of life to exist upon its surface. It is to protect from
moisture in the air that groceries are stored in tins and roots are buried in dry earth.
(3.) Food can be immersed In Brine, Sugar, Vinegar, or Alcohol. A strong solution
of salt has a twofold preservative effect. It extracts water from meat or fish, for
instance, so that their flesh is unsuitable to germ-growth ; and it also removes some
of the nutrient constituents present in the food, leaving it unpalatable to micro-
organisms.
Thick syrups and vinegar are also unfavourable to their development. Moulds loill
grow on the surface of both substances, but the delicate fibres are killed when in contact
with an acid, neither can they push their way down into a dense substance, such as a
thick syrup.
Alcohol hardens food immersed in it, by extracting the moisture, and at the same
time renders them unpalatable to any form of decay.
(4. ) Foods can be preserved by being highly xpiced or strongly favoured with Herb*.
It is believed that certain bitter principles, acids and oils, are present in spices and
herbs, rendering the foods with which they are mixed unpalatable to micro-organisms.
But, once again, a
Note of Warning
must be sounded. The pungent flavour of these favourite food-preservatives may be
employed to mask the first stages of decay by unscrupulous tradesmen. Hence highly
seasoned potted meats or sausages should be regarded with suspicion, unless their
source and mode of preparation is known to the purchaser.
Drawback* to each of these Methods of Food-prf serration
are found in that they affect the flavour and, more important still, they affect in some
degree the digestibility of the substances for the preservation of which they are
employed.
The change of flavour is often pleasant ; rarely, if ever, objectionable ; neither is
the second drawback really serious when preserved foods form only a part of the diet
of adults in good health who are leading an active life. For children they should
always be used sparingly, and ought to be well combined with fresh milk, vegetables,
and eggs, as their nutritive properties are usually affected as well as their digestibility.
When, as in some climates, foods thus preserved necessarily constitute the sole
source of supply, previous soaking in cold water and careful cooking minimize the risks
to digestion, or other forms of ill-health, liable to result.
(5.) Food* can be preferred by the U*e of Chemicals. Different forms of borax,
formalin or formaldehyde, salicylic acid, etc. , all retard the decomposition of food. They
are so easy of employment that, in the case of perishable articles, such as milk, cream, or
sausage-meat, the temptation to use them is often irresistible. No external alteration in
flavour or appearance draw attention to 'their addition to milk, for example ; but,
unfortunately, they seriously interfere with the process of digestion, cause much
dyspepsia, and, in rare cases, loss of life.
Why Chemical Preservatives interfere with Digestion.
The putrefaction of food is due, as has been said, to a process of fermentation
caused by the activities of the micro-organisms of decay. Strange as it may sound,
digestion within the body is due to a corresponding process, far too technical and
complicated to be entered into here. But the fact must not be overlooked that when
such antiseptics as boracic acid or formalin are added to foods to prevent the
10
fermentation known as decay, they also, more or less, prevent digestion after the food
is swallowed. Consequently their use should \te everywhere illegal, as it is in the
United States and, to a partial extent, in England.
The employment of chemicals for the preservation of milk is particularly
undesirable, as it enters so largely into the diet of infants and invalids. It is not
generally known that the natural souring of milk is its own form of protection against
putrefaction, for the germs of decay cannot grow in acid i.e., in soured milk.
Now, sour milk is not unwholesome, except for young children and the nick. But
the changes which take place in milk when, by the addition of chemicals, the normal
formation of lactic acid is prevented are a source of grave risk to the consumers,
specially so to babies.
(6.) The Preservation of Food by chilling if to a Temperature beloir 40 Fahr.
Taking everything into consideration, therefore, this is quite the most satisfactory
method of rendering it unsuitable to the attack of any form of putrefactive germ,
always supposing that the process be carried on under good conditions of care and
cleanliness. No change in flavour, digestibility, or appearance ensues, but the food
must be consumed almost immediately after its removal from cold-storage, for a
tendency to rapid putrefaction develops when such food is brought back into warm,
damp air. This tendency is probably the result of the moisture which at once
condenses on its surface; but, whatever the cause, decay quickly ensues, whether it be
in meat, fish, fruit, milk, or vegetables.
The Effect of a Loir Temperature on Food
is to prevent the development of the germs of putrefaction, or to arrest their activity
if already developed. None of the organisms responsible for decay in food can develop
at a temperature so low as 40 Fahr. or less. Once again, however,
Two Cautions muni be tjiren.
Cold, even zero cold, does not destroy the source of decay if present in food.
The seeds of putrefaction remain merely quiescent, to quicken into active life when
temperature, moisture, and nutrition are once more favourable to their growth.
The temperature of the domestic refrigerator is rarely low enough or steady
enough to be reliable as a certain means of food-preservation. Neither are conditions
of cleanliness and ventilation sufficiently understood by the ordinary housewife to
allow food materials to be safely stored for more than a few hours.
For commercial purposes, and under skilled supervision, this method is rightly
superseding all others for the preservation of foods, whether during transpoit or while
awaiting distribution from market or store.
(6.) MEANS BY WHICH FOOD MAY BE PRESERVED BY EXPOSURE TO CONDITIONS
WHICH WILL DESTROY MICRO-ORGAN ISMS IF PRESENT.
Exposure to great heat, or sterilization, prolonged over a sufficient period, is the
only means of food-preservation which comes under this head.
Moulds are usually destroyed by any temperature above 150 Fahr. , but nothing
less than boiling-point (212 Fahr.) can be relied on to destroy germs ; and even higher
temperatures, which cannot be secured in our kitchens, are necessary to kill the seeds
from which these germs grow.
Two Great Drairbackx to Sterilization
exist as a domestic method of food-preservation :
(i.) All foods are bad conductors of heat, so that the deeper parts of a joint of
meat, for instance, never reach a high enough temperature to ensure their
protection from putrefaction :
11
(ii. ) The very high temperatures realty necessary to destroy the seeds of germs,
as well as the germs themselves, can only be secured by apparatus not as yet
available for home use ; consequently, a false security may be enjoyed if
boiling only be accepted as sufficient protection to our food.
Protection of Water by Boiling.
" What, then," you will ask, "about the protection of water by boiling?" In this
case the difficulty can be overcome to a great degree, because, in the first place, every
drop of water can be raised to boiling-point, given sufficient time. We know that the
germs of disease which are conveyed to us by water are killed if boiled for at least
half an hour. Therefore, where water is suspicious, the day's supply for drinking
purposes can be boiled for that length of time.
"But how about the seeds of these germs," you will inquire; " should not they
also be destroyed?" This further protection can be extended to water by allowing it
to cool and stand for some hours and then boiling it for a second half-hour. In the
interval the seeds of any germs, if present, will develop into germs, in which form a
temperature of 212 Fahr. means death to them.
It is believed that the germs of disease most often carried by milk namely, those
of tuberculosis are completely destroyed by a temperature rather below boiling-point ;
but, unfortunately, milk appears to suffer some change when cooked for the necessary
time, which renders it less wholesome for children.
A Necessary Precaution for Soiled Milk and Water.
Please note the importance of covering all water or milk which Aa,s- been boiled.
It must be understood that the whole universe swarms with micro-organisms, some
of which are floating in the air, from which they fall upon our persons, our property,
and our food. Happily, most of these invisible millions are our good friends, and not
the least of their very valuable services is to protect our bodies and all forms of food
against the invasion of disease and putrefaction.
(Fir, 5.)
Food-preservation by means of a
layer of fat.
Sometimes these benign and kindly germs are overpowered by the invaders. If
this occur in our bodies, we are sick ; if it occur in our food, decay sets in. Now, the
misfortune is that when milk or water is boiled, we kill our friends as well as our foes
among these germs. Therefore, if the undesirable germs, occasionally present in the
air, in dust, or in dirt, fall upon the surface of this defenceless milk or water, they can
carry on their mischievous activity unchecked. Sterilized food is defenceless food ;
therefore it must be sheltered by covering of a suitable kind.
A slip of glass is to be preferred for this purpose. It fits closely to the rim of the
jug or bowl, arid shows every spot of dirt or greasy finger-mark. A cloth, however
clean it looks, may have been exposed to much dirt or handled by many grimy fingers
before it is used to cover a jug of boiled water or a bowl of boiled milk.
Exposure to High Temperature.
Exposure to a high temperature over a prolonged period alters in some way the
character of the food so treated. While protecting it in one direction, the heat seems
12
to interfere in another with its nutritive properties. The food seem less digestible and
its " livingness" seem in someway destroyed. The reasons for these subtle changes
have not vet been clearly traced.; that they occur is unquestionable.
We must now pass on to a review of the methods employed.
(c.) KEEP FOOD PROTECTED FROM THE ATTACKS OF GERMS, YKASTS, AND MOULDS.
Of these there are several, most of them being quite familar to us.
(1.) The Exclusion of Air. As air is necessary to the life of most of these micro-
organisms, they cannot develop in or attack food from which all air is excluded.
A favourite domestic application of this method of food-preservation is to cover the
surface of potted meat or fish, for example, with a layer of lard or other fat, which is
impervious to air. Oil or paraffin-wax serve the same purpose.
Commercially, oil is also employed to preserve fish, such as sardines, herrings, or
anchovies ; and in Italy a few drops of oil seal the necks of wine-flasks, instead of
corks.
The exclusion of air is, of course, one secret of success in jam-making or preserving
fruit or vegetables, combined with a very high temperature, which destroys micro-
organisms if present. We all know that if a jar is not brimful of boiling fruit and
syrup, so that even the tiniest space is left for air to occupy, decay invariably follows,
usually in the form of moulds.
The enormous quantity of
Canned Food*
on the market illustrates the wide utilization of this method of food-preservation by air-
exclusion, combined with previous sterilization. Ill-effects rarely follow its consump
tion ; nevertheless, every one who uses canned foods should never omit to practise the
following precaution :
(a.) Always turn out the contents of any tin into a glass, china, or earthenware
dish immediately the tin is opened. This precaution is quite as necessary in the case of
fish preserved in oil, though it is usually neglected.
This precaution is necessary, because the exact extent to which the natural acids
of food corrode the inner surface of tins is not yet known ; but injurious metallic salts
are occasionally found, and such chemical action is more liable to occur when the tin is
opened and the contents become exposed to the external air than when it is hermetic-
ally sealed. For this reason food should, when possible, be alwavs preserved in glass
or china vessels.
(FiG. 6.)
\Vlii>rc germs Hourish and flies breed.
(b.) Form the habit of examining each tin before opening it, as to the soundness of
its contents :
(i.) By the Eyt. Slight inward bulging, or concavities, of the surface are a good
sign. Outward bulgings, or convexities, are a danger-signal, and show that
the gases of putrefaction have formed :
13
(ii. ) By the Ear. Tap the tin with a pencil or the finger-nails. A high ringing
sound is what should result. A dull, dead sound is a warning that all is not
well within.
If the process of sterilization were incomplete or if the tin were insecurely sealed,
sooner or later the process of decay begins ; and the effect is to give rise to these
external signs and sounds. The contents of such tins are unfit for human food.
(2.) The Preservation of Food by Suitable Storage. The requirements for this
method of protection should be now known to the reader. Food must be kept
(a.) Dry;
(&.) Cool;
(c.) Clean ;
(d. ) Protected from the access of decay.
(Fie. 7.)
14
How does the ordinary housekeeper provide for these requirements ?
No room is ever entirely free from the presence of moulds, yeasts, and bacteria,
though in cleanliness, pure air, and abundant light we possess three powerful agents for
their control.
Never forget that darkness, damp, and dirt favour their growth and foster their
increase.
Cellars and dark, ill-ventilated cupboards are not fit places for food-storage.
A Good Larder.
To be trustworthy, a good larder must be so light that every corner and crevice
can be kept clean. It must have a through draught of air, so that moulds and germs shall
be carried through it on a current ot air. If the air in a larder be still, any micro-
organisms it contains will gradually sink on to the contents of the shelves and breed
decay. The shelves and walls should be made of or covered with some impervious
materials, so that if grease or milk or syrup be spilt, they can be completely washed off
and leave no residue to afford food for the seeds of decay.
It must be dry, or food will taint and mould in spite of all care. Fig. (7) illus-
trates a home-made effort to secure all these requirements at moderate cost. This larder
is made of four mosquito-proof doors. Inside, where each door joins another, mouldings
are fixed, so that no insect can force its way in from without.
(FiG. 8.)
Saving Steps " Bulletin issued l>.v Cornell t'nivcrsit.v, U.S.A.
15
The woodwork and shelves have had two coats of Solignum (an excellent wood,
preservative, so pungent that it banishes insect life and also makes the surfaces
impervious). This can be renewed every lew months.
This larder stands on a north verandah, in a position which allows a free circulation
of air all round it ; where also ample light reveals dust, grease spots or stains.
Daily and Seasonal Care of the Larder.
Daily in summer, at longer intervals in winter, the shelves should be wiped over
with a strong solution of formalin (one tablespoonful of formalin to six of water). This
is not only a good disinfectant but a destroyer of injects.
In cold weather it is advisable to minimize the inconvenience of frozen food by
surrounding the larder at night, or all day in snowy weather, with a washable curtain
of burlap or heavy sheeting.
A U-wful Supplementary Larder
for winter use is shown in Fig. (8), which is in general use in the United States. The
box should exactly fit outside a north window, and should come half-way up the lower
sash. It should be about 18 inches deep and fitted with a shelf. When the window is
opened the contents of the box are easily accessible ; and in cold weather the sash may
remain raised, in order ihat the warm air from the room may keep the food from
freezing. Of course, its contents must be protected from the dust of the room by a
muslin curtain, and the inside of the box should be well treated with Solignum or
creosote ; or the box may be lined with white oilcloth.
Legal Powers
to insist upon suitable accommodation for the domestic storage of food are exercised in
England by the London County Council and other large municipalities. The owner who
occupies or lets on hire any house, rooms, or lodgings without such provision is liable to
a penalty of $10, and a fine of $5 a day, until he obeys the Council's order to supply a
" sufficient and suitable" larder for each occupant from whom he receives rent.
Cellar-storage of Food
is only allowable under the following conditions : The cellar must be perfectly dry.
The walls and floor should be laid in concrete or, better still, in cement, to keep out
moisture. This allows them to be washed at intervals and kalsomined twice a year.
A cellar used for food-storage must be well ventilated and light. Therefore there
must not only be windows, but they must be kept clean and made to open. It is also a
good plan to have small openings in the walls, well distributed, and covered with
mosquito-netting. Through currents of air will thus be ensured.
During the winter, when roots and potatoes need storing in the dark, a curtain
can be hung over one or more windows, and periodically removed for sweeping.
A cellar so constructed and kept is serviceable during the heat of summer for
storing fresh provisions, always supposing that strict cleanliness be practised.
THE PRESERVATION OF GROCERIES, FRUIT, VEGETABLES, ETC.,
IN THE HOME.
It will now be realized how sound are the methods in common use by the well-
trained housewife for protecting foodstuffs from the attacks of micro-organisms, though
often she may have been unable to give a reason for what she does.
Potatoes and root vegetables remain plump and fresh when kept dry and sheltered
from the attack of moulds, etc., by a covering of dry earth.
Cranberries are correspondingly protected by the water in which they are
immersed.
10
Eggs can only become " bad," when stored beneath the surface of a 10-per-cent.
solution of water-glass, from the activity of micro-organisms already within their
shells before preservation.
The object of storing crackers and cakes in tightly closed tins is, of course, the
exclusion of moisture. Similarly, sugar, tea, and other groceries are kept in tin-lined
or earthenware utensils.
Hams, bacon, or smoked meats or fish should be put into cheese-cloth or linen
bags before being hung in a dry, well-ventilated place.
Apples, lemons, tomatoes, and similar fruits should be wrapped separately in soft
paper after wiping, and stored on airy shelves, which may be covered with straw or
chaff or sawdust.
The reason for this care, which to some may seem superfluous, lies in the channels
by which the germs of decay or the seeds of moulds reach the foodstuffs they destroy.
The two channels of primary importance, and those only to which reference can
here be made, are :
(a.) The air.
(b.) Flies.
(a.) THE AIR.
It has already been pointed out that these mischievous atoms of microscopic life,
the organisms of decay, are always present in the atmosphere, with the exception of
mid-ocean and the summits of very high mountains.
When the air travels fast, they are rushed along in its currents; but so soon as it
is still the micro-organisms, with the dust of which they form an ingredient, gradually
drop down on to the surrounding surfaces.
If these be moist and the air be warm, the chances are the seeds of decay will
begin to grow. They will certainly do so if the substance on which they settle is one
on which they can feed.
Now, invisible moisture collects in the "pits" round the eyes or stems of fruit
such as apples, pears, or tomatoes ; or in any dent in their skins, or in the crevice
where two fruit rub shoulders.
Porous Paper a-s a Fruit-preservative.
Soft porous paper wrappings serve a double purpose. They absorb moisture from
the air before it reaches the fruit at all, and by covering the fruit the}' prevent germs
or moulds from falling on to its surface.
(6.) FLIKS.
In conclusion, a few words must be said about the great importance of the protection
of food from flies, which are known to be a fruitful source of disease in food as well as
a channel by which the sources of decay menace its soundness and sweetness.
"Fly-spots" consist of the saliva and excrement of flies, as they pass impartially
from cow-dung or night-soil to the baby's milk or the family sugar or cake. It is not,
therefore, surprising that the fly is now shunned as one of the chief carriers, not only of
dirt and decay, but of the infection of typhoid fever, tuberculosis, and other dangerous
diseases.
The Structure af a Fly and it* Haldt*
adapt it peculiarly for the conveyance of filth, in addition to the micro-organisms which
swarm these "fly-spots." The six, many-jointed legs are densely hairy, and each leg
terminates in a pair of hooks, with a "glue-pad" attached to each hook. A glance at
Fig. (10) will make clear the enormous power possessed by a fly for carrying tilth from
the unclean to the clean.
17
Flies breed in house-refuse, manure, or any decaying matter. They increase with
such rapidity that, assuming one-half of one fly's output of eggs to hatch out, live, and
raise families of their own, the number of flies from this single source would be 216,000
in thirty days, and in forty days it could amount to over 2,000,000.
(Fie. 9.)
The House-fly, with larva and pupa ; all highly magnified.
Larva.
This stage lasts about six days.
Pupa.
This stage lasts about throe days.
If a house is infested with flies, the source of the trouble is usually near at hand ;
for generally they do not fly a greater distance than 200 yards from their breeding-places,
though a high wind may carry them much farther.
Coal-oil they abhor. It is wise, therefore, to wash over windows and round the
frames with coal-oil at intervals during the summer, and a good dressing of turpentine
round every crevice of the windows in the early spring will often destroy .flies which
have spent their winter in these haunts.
It is worth while, also, to wipe over the network of the larder daily in summer
with coal-oil ; and saucers containing one spoonful of formalin to six of water should
be placed about wherever flies are seen to congregate. They are attracted to the
fluid and killed.
18
Most important of all, no heap of garbage, no refuse of food, no filth, should be
allowed to accumulate. Burn in the stove all that the pigs cannot eat ; and any necessary
rubbish-heap which cannot be otherwise disposed of during the period when burning
(FiG. 10.)
The leg, claw, and glue-pads of a fly. highly magnified.
is illegal, cover it, after each addition of refuse, with a thin layer of earth ; which
simple precaution will prevent it from becoming a flies' nursery. If coal-oil is poured
over the earth, it will act the more efficaciously.
CONCLUSION.
Unfortunately, space does not permit the risks to food to be dealt with which are
incidental to careless and dirty methods of handling in transport or while under
display in market or store.
The subject of food-preservation is, indeed, a vast one, calling for much more
detail than can be adequately included in one bulletin. It is, however, to be hoped
that the reasons given for well-established customs, the suggestions made on points
liable to be overlooked by the busy housewife, the hints offered on unsuspected
dangers, may add interest to the work of some women, stimulate others to increased
exercise of the " eternal vigilance 1 ' often a burden to the unintelligent worker, incite
all to a desire for fuller knowledge, and thus promote the welfare of many
households.
1!)
NOTICE.
The Department of Agriculture is issuing the following series of bulletins
prepared by Miss Alice Ravenhill. Shawnigan Lake. B.C.. to be available for
distribution among the members of the Women's Institutes throughout the
Province. :
1. The Place and Purpose of Family Life.
2. The Preparation of Food.
3. The Preservation of Food.
4. Some Labour-saving Devices in the Home.
5. Food and Diet.
G. The Art of Right Living.
7. The Care of Children.
BULLETINS ISSUED BY THE DEPARTMENT OF AGRICULTURE.
No.
7. Flax.
8. Feeding Farm Animals.
20. Varieties of Fruit Recommended (revised).
25. Orchard Cleansing.
28. Production of Eggs.
29. Poultry Industry on the Pacific Coast.
30. Guide to Bee-keeping in British Columbia.
32. Control of Bovine Tuberculosis in British Columbia.
33. Fruit-growing Possibilities. Skeena River and Porcher Island
Districts.
34. Fruit-trees and Black-spot Canker.
35. The Place and Purpose of Family Life.
36. The Preparation of Food.
37. The Preservation of Food.
3S. The Construction of Silos.
Applications for bulletins published by the Department of Agriculture
should be addressed to the Secretary. Department of Agriculture. B.C.
ALICE RAVEN HILL,
Fclloic of the lioyal Sanitary Institute; Certificated Lecturer
Xational Health Society, Great Hritain ami Ireland.
Author of " I'ractical Hitaiene for I'xc in Schools";
Kleiiieiitx of Sanitary Laic''; ' Koine Characteristics
and Requirements of Childhood"; "Household Admin-
istration"; "Household Foes," etc.
Late Lecturer an Hyuienc, University of London. Kini/'s
(^olleye for Women.
VICTORIA, B.C.:
Printed by WILLIAM II. CVLI.IX, Printer to the Kind's Must Kxccllent Majesty.
1912.
A!
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