The aegis & intelligencer. [volume] (Bel Air, Md.) 1864-1923, 1886-08-20
The Theory Of Fermentation as it APP
plies to Canning.

!
For the Egis and Intelligencer.
Fermentation is chemical decomposition
whose first results are alcohol and carbonic
acid; afterwards acetic acid or vinegar. II
starch be the substance exposed, sugar is de-
veloped by the first action, as in the raising
of bread or the, mailing of barley.
1t is the Development OF carbonic acid gas
that Springs" the imperfectly processed can.
There can be no fermentation without the
| presence of the germs of the yeast plant, but
those germs are in the air and on every thing
that the air touches.
The apples are crushed, the juice pressed
out under the screws, and the cider, whether
exposed in open vessels or closed in tight
casks, within two or three days depending
on the temperature) begins TO ferment. 1t is
found to be undergoing chemical change !;
its sugar or sweetness is decomposcd, chang
ing to carbonic acid gas and alcohol. Large
quantities of carbonic acid gas are developed
and pass of, throwing the liquid up in little
jets in an open vessel, not unlike boiling, as
the gas escapes if the vessel be closed the
cork is thrown out, or the vessel burst The
juice does not ferment in the apple or in the
grape, because it is there sealed up air tight,
and the yeast germs, which are thick upon
the outside skins of the fruits, cannot pene.
trate. Vegetable mixtures exposed or even
corked in bottles without heat having been
applied, were early observed to undergo this
change, and under the microscope to show
there living germs which were first thought
to be ANIMAL but which are now known to
be vegetable, and scientists began to reason
that under favorable circumstances life comes
forth spontaneously; but it was soon found
that fthe air was perfectly excluded and the
vessel with all its contents closed at a tenn
nNfO mn al,n nlnI,.
ensued, no ferment set in.
think ii was Prof Huxley, the English
scientist, who among others. pursued an ex-
haustiVe course of experiments on the sub
ject. He found if he strained the air through
thick mats Of dampened cotton, or large
masses of chemically pure water into vessels
containing the vegetable solutions, no
changes ensued. He prepared some TASKS
on the highest peaks of the Alps, where the
air might be supposed to be free from all or
ganic matter, and only a few of the mountain
TASKS afterwards showed signs of change;
and in various ways it has been clearly dem
onstrated that without life no life afterwards
appears, no fermentation ensues. 1t has
been repeatedly proven that at Pig degrees
Leaf, the temperature of boiling water will
kill these germs.
Now the application of these facts to can-
uluS ulC CtsN, anu us Ill w lSC CUcullCHl cA-
periments the expected results are sure to
follow, nature never deceives her votaries.
We may premise that the outside of the to-
mato, the tables and vessels are alive with
the microscopic germs of the yeast plant, and
as the tomato is crushed, mingle with its
substance. Now the necessity is to kill these
germs by heat, at least to bring every parti-
Gle of the contents of the can up to the tenn
peraturc of boiling water, and Theoretically
seal it at this temperature. If any cooler air
penetrates before the can is sealed up, it ne
cessarly carries in with it the fatal germs of
decomposition. If the fruit be hard and full
of cores much longer heating process will
be necessary to bring all TO the required tenn
perature. In processing corn il is customary
to increase the gravity of water by admixture,
and so raise its boiling temperature The
same result could be reached by using a
steam-tight vessel, and any required temper
ature that the strength of the vessel would
admit of, could be SO obtained.
Preserves with sufficient sugar in them to
make thick syrup do not ferment, because
the yeast plant must have certain proper
ton of water to live and thrive in. Alcohol
in sufficient proportion will kill these germs
and prevent fermentation, but weak mix
ture of spirits seems no encouragement, as
the first results of fermentation after sugar
are alcohol, and from diluted spirits we make
vinegar by the same process.
GGC.
O(thlnlld ,ScI0OI EuILstOH