CANNING AND PRESERVING FRUIT IN THE HOME 
ing must be continued for an hour or 
more to insure their complete destruc- 
tion. Generally speaking, in order to kill 
the spores the temperature must be high- 
er than that of boiling water, or the 
article to be preserved must be cooked 
for about two hours at a temperature of 
212 degrees Fahrenheit, or a shorter time 
at a higher temperature under pressure. 
Yeasts and their spores are, however, 
more easily destroyed by heat than bac- 
teria spores. Hence, fruits containing 
little nitrogenous material are more 
easily protected from fermentation than 
nitrogenous foods in which in general 
fermentation is caused by bacteria. Of 
course it is not possible to know what 
kinds of organisms are in the food one 
is about to can or bottle; but we do know 
that most fruits are not favorable to the 
growth of bacteria, and, as a rule, the 
yeasts which grow in fruits and fruit 
juices can be destroyed by cooking 10 or 
15 minutes at a temperature of 212 de- 
grees Fahrenheit. If no living organisms 
are left, and the sterilization of all appli- 
ances has been thorough, there is no rea- 
son why the fruit, if properly sealed, 
should not keep, with but slight change 
of texture or flavor, for a year or longer, 
although canned fruits undergo gradual 
change and deterioration even under the 
most favorable conditions. 
When fruit is preserved with a large 
amount of sugar (a pound of sugar to a 
pound of fruit) it does not need to be 
hermetically sealed to protect it from 
bacteria and yeasts, because the thick, 
sugary syrup formed is not favorable to 
their growth. However, the self-sealing 
jars are much better than keeping such 
fruit in large receptacles, from which it 
is taken as needed, because molds grow 
freely on moist, sugary substances ex- 
posed to the air. 
Molds and Molding 
Every housekeeper is familiar with 
molds which, under favorable conditions 
of warmth and moisture, grow upon al- 
most any kind of organic material. This 
is seen in damp, warm weather, when 
molds form in a short time on all sorts 
of starchy foods, such as boiled potatoes, 
717 
bread, mush, etc., as well as fresh, 
canned, and preserved fruits. 
Molds develop from spores which are 
always floating about in the air. When a 
spore falls upon a substance containing 
moisture and suitable food it sends out a 
fine thread, which branches and works its 
way over and into the attacked substance. 
In a short time spores are produced and 
the work of reproduction goes on. 
In the first stages molds are white or 
light gray and hardly noticeable; but 
when spores develop the growth gradu- 
ally becomes colored. In fact, the condi- 
tions of advanced growth might be 
likened to those of a flower garden. The 
threads—mycelium—might be likened to 
the roots of plants and the spores to the 
flower and seeds. 
Mold spores are very light and are 
blown about by the wind. They are a 
little heavier than air, and drop on 
shelves, tables and floor, and are easily 
set in motion again by the movement of 
a brush, duster, etc. If one of these 
spores drops on a jar of preserves or a 
tumbler of jelly, it will germinate if 
there be warmth and moisture enough in 
the storeroom. Molds do not ordinarily 
cause fermentation of canned foods, al- 
though they are the common cause of the 
decay of raw fruits. They are not as 
injurious to canned goods as are bac- 
teria and yeasts. They do not penetrate 
deeply into preserves or jellies, or into 
liquids or semi-liquids, but if given time 
they will, at ordinary room temperature, 
work all through suitable solid sub- 
stances which contain moisture. Nearly 
every housekeeper has seen this in the 
molding of a loaf of bread or cake. 
In the work of canning, preserving and 
jelly making it is important that the food 
shall be protected from the growth of 
molds as well as the growth of yeasts 
and bacteria. 
To kill mold spores food must be ex- 
posed to a temperature of from 150 de- 
grees Fahrenheit to 212 degrees Fahren- 
heit. After this it should be kept in a 
cool, dry place and covered carefully that 
no floating spore can find lodgment on its 
surface. 
