Refrigeration is preservation by holding food at a low
temperature. Freezing and cold storage are means of
keeping food for long periods; cellars and ice boxes, for
short periods.
Freezing or packing in dry snow or ice checks the growth
of bacteria as long as the food is in a frozen condition.
Food deteriorates quickly after thawing out, and should be
used immediately. Meat and fish are most commonly frozen.
CANNING FRUIT 191
Cold storage, or keeping food in cold, dry storerooms
artificially cooled to just above the freezing point, preserves
food. Eggs, fruit, vegetables, butter, and meat are kept
very extensively and for considerable periods in cold-
storage plants. Cellars and ice boxes are cold-storage
devices for homes.
Canning, or sealing sterilized food in air-tight sterilized
jars, is a common household method of food preservation.
Boiling for 20 minutes will generally kill most forms of
bacteria. Fruits, vegetables, and meats are preserved by
canning.
Removal of Moisture. — Bacteria require considerable
moisture in a material in order to grow in it. Drying a
food, therefore, preserves it from decay. Flour, crack-
ers, cereals, and many other foods do not spoil because
they are dry. Fish, fruits, berries, and beef are other
familiar examples of this preserving principle. Dried
foods must be kept in a dry place so as to prevent the ab-
sorption of sufficient moisture to give the germs of decay
on or in them a chance to grow.
The excluding of air also aids in preserving some food
products. This is accomplished in the case of eggs by
coating with paraffin or vaseline or putting them in water
glass; likewise grapes are packed in cork.
Preservatives. — Antiseptics are materials that do not
kill bacteria but which retard or prevent their growth.
Those used to preserve food should be harmless to the body.
Common examples of these are: —
Sugar, — Bacteria cannot grow in a food containing a
large proportion of sugar. Jelly, marmalade, and preserves
keep well for this reason. Raisins, dates, figs, and candied
fruits are other examples. Condensed milk is preserved
by the addition of 30 or 40 per cent of sugar.
192 DOMESTIC SCIENCE
Salt. — ^Salt prevents bacterial growth in a similar way
that sugar does, and it also takes up moisture. Common
foods salted are fat pork, beef, fish, hams, and bacon. Salt
in butter and cheese makes them keep better.
Acids. — Acids protect food from bacteria and give new
flavors. Vinegar (acetic acid) is used in making pickles,
and lactic and acetic acids that develop in sauerkraut act
as preservatives.
Spices are antiseptic and are another common means of
preventing the action of bacteria on food. Spices are
used in mincemeat for flavor and at the same time they
help to preserve it. Sage and spice used in sausage and
spice in fruit cake perform the same functions.
Smoke. — Meats and fish are often preserved and flavored
by smoking, combined with the salting and drying that
accompany the process. It must be remembered, however,
that the smoke does not penetrate deeply into the flesh,
but is merely a protective covering, so that any bacteria
or parasites within are not killed. Smoked meat is unsafe
to eat without thorough cooking.
Page 81
Presented as published in 1914. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
Refrigeration is preservation by holding food at a low temperature. Freezing and cold storage are means of keeping food for long periods; cellars and ice boxes, for short periods.
Freezing or packing in dry snow or ice checks the growth of bacteria as long as the food is in a frozen condition. Food deteriorates quickly after thawing out, and should be used immediately. Meat and fish are most commonly frozen.
Cold storage, or keeping food in cold, dry storerooms artificially cooled to just above the freezing point, preserves food. Eggs, fruit, vegetables, butter, and meat are kept very extensively and for considerable periods in coldstorage plants. Cellars and ice boxes are cold-storage devices for homes.
Canning, or sealing sterilized food in air-tight sterilized jars, is a common household method of food preservation. Boiling for 20 minutes will generally kill most forms of bacteria. Fruits, vegetables, and meats are preserved by canning.
Removal of Moisture. — Bacteria require considerable moisture in a material in order to grow in it. Drying a food, therefore, preserves it from decay. Flour, crackers, cereals, and many other foods do not spoil because they are dry. Fish, fruits, berries, and beef are other familiar examples of this preserving principle. Dried foods must be kept in a dry place so as to prevent the absorption of sufficient moisture to give the germs of decay on or in them a chance to grow.
The excluding of air also aids in preserving some food products. This is accomplished in the case of eggs by coating with paraffin or vaseline or putting them in water glass; likewise grapes are packed in cork.
Preservatives. — Antiseptics are materials that do not kill bacteria but which retard or prevent their growth. Those used to preserve food should be harmless to the body. Common examples of these are: —
Sugar, — Bacteria cannot grow in a food containing a large proportion of sugar. Jelly, marmalade, and preserves keep well for this reason. Raisins, dates, figs, and candied fruits are other examples. Condensed milk is preserved by the addition of 30 or 40 per cent of sugar.
Salt. — ^Salt prevents bacterial growth in a similar way that sugar does, and it also takes up moisture. Common foods salted are fat pork, beef, fish, hams, and bacon. Salt in butter and cheese makes them keep better.
Acids. — Acids protect food from bacteria and give new flavors. Vinegar (acetic acid) is used in making pickles, and lactic and acetic acids that develop in sauerkraut act as preservatives.
Spices are antiseptic and are another common means of preventing the action of bacteria on food. Spices are used in mincemeat for flavor and at the same time they help to preserve it. Sage and spice used in sausage and spice in fruit cake perform the same functions.
Smoke. — Meats and fish are often preserved and flavored by smoking, combined with the salting and drying that accompany the process. It must be remembered, however, that the smoke does not penetrate deeply into the flesh, but is merely a protective covering, so that any bacteria or parasites within are not killed. Smoked meat is unsafe to eat without thorough cooking.