Evening star. [volume] (Washington, D.C.) 1854-1972, 1904-07-15
THE BACTERIA IN MILK
GOOD AND BAD VARIETIES
KNOWN TO SCIENCE.
Agency Which Puts Cream Into Condi-
don for the Manufacture Of But
ter and Cheese.

''Hew to keep milk sweet for the longest
possible period Is a problem that has inter-
ested housewives on a small and dairymen
on large scale ever since milk became a
household necessity said an official of the
local health Office to a Star reporter.
"Only within very recent years, however.
has there been any visible hope that a way
may yet be found to postpone souring for
an Indefinite period. without even the neces-
sity Of cold storage. During these recent
years the modern science OF bacteriology
has discovered tho secret of this incon-
verient phenomenon The dairyman no
longer blames the cow for producing a sub
stance that will inevitably curdle. but
curses a goodly number of bacteria that
get into the milk afterward and sour 1t by
the production of certain chemical changes.
These bacteria are so numerous that
they have not yet been completely inves-
tigated, although the subject has been un-
der careful investigations in many continen-
tai laboratories and on this side or the
water much has already been accomplished
The psychologists and the dairyman really
work hand in hand in the Improvement OF
modern dairy products, for the bacterlolo,
gists are gradually finding the why anu
wherefor of various methods that the dairy.
men have evolved through centuries OF
practical experience. But practical ex-
perience in the dairy has always given I'M
even results. and the direct value or the
new partnership lies in the elimination OF
everything except the particular bacteria
that are most kindly disposed toward the
milk producer
Even with the general knowledge nova
DAYS of the universal presence Of these
bacteria many of them Injurious TO man
kind but a greater number doing their
work for his direct or 1ndlrect ptLeil.s
probably few persons outside the RANKS VI
ofn
important they are in the marketing o!
milk, and especially into the evolution OF
butter or cheese. There are indeed com
paratively few bacteria In the milk untli ~ i.
reaches the air on its way from the co"
to the milk pail. This little journey Is long
enough to admit a large number OF micro
organisms, and the milk itself Is SO excel-
lent a place that they increase with mar
velous rapidity The dairyman finds IN
them a twofold character Roughly speak
ing they are a curse to the milk seller
and blessing to the maker OF cheese ,,3 ait ~
butter If no bacteria got INTO tne nli!k ~
would probably remain sweet lndennltely,
while on the other hand, except for some
of these same bacteria, humanity Woulu
probably never have acquired It's TASTE loa
bread and butter or its fondness ior cheese
sandwiches
The Souring Process.
Securing of milk, which has long peeh
considered a normal property or the 'iiih
itself. has been proved to result from Inc
action of many different kinds OF bacteria
all of which convert the milk and sugar III
a nan of milk into Tactic acid. which. IN
turn imnarts a sour taste to the milk ana
eventually makes 1t curdle. Other pacteii,
spoils the milk in various ways Whlch nav
aiways been attributed by the dalrymen
70 circumstances beyond their personal
control And the net discoveries so far
made have been practically to eliminate
many of these bacteria by greater cdrelu W,
ness in the conditions under winch tiio
milk is produced title r,,oaarr
hacteriolosy is constantly busted with the
problem of keeping the bad bacteria out
of the milk that is intended to MI the
worlds milk pitchers. it is equally pussy
in staIdving and supplying the good bac-
terra that are absolutely necessary TO per
feet our butter and produce our afterollhsa
cheeses Although butter can be mace
from cream without bacterial assistance,
cheese would be an impossibiity; and the
butter that is not partly MADE py men
action is very much like cream IN taste anu
not at all like butter to the average paia'e.
"Anybodv who has had any acquaintance
with a butter churn knows that cream IN
order to produce the best tasting buttef'
must be 'ripened'-in other WORDS ions We
fore bacteria has been discovered the put
ter maker used to set his cream aside ana
aIiow his unsuspected helpers to produce
certain chemical changes in the cream De.
fore 1t was churned. These changes, ~
carried too far, spoil the cream but II
stopped at the right hour vastly improve
II for butter making.
Bacterial Agency.
scientific examination of this phenom-
enon discovered that 1t was bacterial &C
ton that produced these changes and dis
covered also a reason for the perplexlng
fact that the changes were not uniform.
There are bacteria and bacteria and by
further examination of them the bacter-
iolC gists have found the best bacteria for
the butter maker, have found means 10
cultivate these particular dairymen's as
sistants in what are called pure cultures
and these pure cultures are now used in
butter making in much the same fashion as
prepared yeast which is another result Of
bacterial assistance, is used In the bakery.
Their use has developed during the last
six years to such an extent that June but
ter formerly obtained only In spring and
early summer is now produced by many
dairymen straight through the season. The
June butter of d decade ago, that Is, was
due to the presence of particular bacteria.
not present earlier in the year, which
have been captured and are now widely
cultivated by expert psychologists.
What has been accomplished in way of
furnishing the proper bacteria for butter
making points naturally to the hope that
the same thing may be accomplished in
the process of cheese manufacture. So far.
however, although some advance has been
made in the right direction, this ideal con-
dition has not been established, although
the fact has been proven that the cheese
makers bacterial allies are of even great
er Importance than those that assist the
butter makers. Just different kinds of
be cteria are the important factors in pro-
duc,ng butter Of various degrees Of ex-
cellence SO far different bacteria undoubt-
eddy Is responsible for the wide variety of
cheeses. If 1t were possible to select and
cultivate these various bacteria it would
follow that the production of each kind of
cheese could be reduced almost to a
Matthew, teal science"