The Ogden standard. [volume] (Ogden City, Utah) 1902-1910, 1909-07-10
BITTER AND ROPY MILK
The Source and Nature of the
Bacteria Which Make These
Conditions Possible.
BY I. A. RoGEEb,

NsTcd States Bureau Of Animal Industry
Tho distinct sitter taste which some
times appears in milk may be caused
by 0) certain weeds that the COW has
eaten, 60 an abnormal condition OF the
udder (3) an advanced period OF lacta-
tion. or lD the action Of certain bac-
tcria. only the fourth cause OF bit
ter milk viii be discussed In this
paper.
1t Is probable that the bacteria caus-
ing bitterness arc not at all uncommon
and that they could bo found in many
lots OF milk showing no bitterness
Some OF these bacteria form acid and
sour the milk: the moro common forms.
however, form little acid and are
checked by the growth OF the Tactic
acid bacteria.
Nearly all of them form spores and
thus survive heating. which destroys
the Tactic acid bacteria. For this rca-
son bitterness has been most frequent
ly observed In pasteurized and imper-
fectly sterllized milk
The few remaining spores cerminatc,
and as they are unhipdercd by the
presence of Tactic acid bacteria they
soon reach unusual number and the
bitter flavor appears.
Bitter milk may appear as an cpl
demic, perslstlng day after day. and
causing great trouble. This may be
due to somo constant localized source
OF infection which adds each day un-
usual numbers of bacteria TO the milk.
In some cases 1t has been found that
tho udder of a cow was infected. This
should be determined by carefully
ole nirr h.. nd Of oil
milking from each quarter Of the uddcr
Of each cow into fruit jars or bottles
which have previously been cleaned
with boiling water.
In case one of these samples shows
n well-dcveloped bitterness while 9TH
crs remain normal. il may be assumed
that the source OF infection is the I'D
der OF the COW. In that oase there
should be injected into the udder after
each milking a solution OF one part of
hyposulphite of soda In 100 parts of
water.
1t Is possible in many cases that the
source OF infection is not localized II
through some combination of oircum-
stances tho Tactic acid bacteria arc
suppressed. other kinds become pre-
dominant
The utensils. the milk room and the
stable gradually become inocuated
with these bacteria OF their spores and
each now lot OF milk is thoroughly in
oculated
The bitterm milk bacteria may be cne
OF the new forms. In this event 1t may
be necessary, after thoroughly clean
ing everything coming in contact with
the milk. to introduce some good sour
milk from a ncighboring dairy.
In this way the normal fermenta-
tion may be restored and tho objection
able bacteria suppressed
Ropy milk is so far as known, In no
way detrimental TO health The ia
NOUS Edam cheese is nearly all n1ado
from milk which has undergone this
fermentation.
Most people. however. object serl-
ously 10 milk with my tendency to
form threads. This trouble frequently
affects the milk of a dairy day after
day and is removed only by tho most
drastic measures.
Outbreaks of this nature frequently
occur In the cold months. because the
bacteria of this group thrive better at
low temperatures than the Tactic acid
bacteria which hold them in check un-
der normal conditions.
In one case 1t was found that these
bacteria were abundant in the dust Of
the stable. The trouble was removed
by thoroughly cleaning and white
washing.
In another serious and persistent out
break it was found that the milk as
1t came from the dairy contained few
OF no roDy milk bacteria, but they
werc abundant In the water tank I'm
which tho milk was held overnight.
The small amount OF water occa
slonally splashod into the cans add
cd sufficient bacteria to make the milk
ropy In comparatively short time.
Tho utensils and floor had become
so thoroughly imprcgnated with this
organism that milk exposed in tho
room or strained through the wire
strainer became ropy without contain
lnation with the water
The trouble was removed by thor
oughly scaldlnE all the utensils. dis
injecting the floor with a per cent
sulphuric acid solution and destroy-
Ing the organisms in the ice water bv
adding potassium bchromatc-In the
proportion Of one part To 1000 parts
OF water.