Ottumwa tri-weekly courier. [volume] (Ottumwa, Iowa) 1903-1916, 1909-06-17
BITTER And ROPY MILK
The Source and Nature of the
Bacteria Which Make These
Conditions Possible
BY L. A. ROGERS,

United States Bureau of Animal Industry.
The distinct bitter taste which some
times appears in milk may be caused
by ID certain weeds that the COW has
eaten, (2) an abnormal condition of the
udder, go an advanced period of lacta-
tion, or 90 the action of certain bac-
teria. Only the fourth cause of bit
ter milk will be discussed in this
paper.
1t is probable that the bacteria caus-
Ing bitterness are not at all uncommon
and that they could be found in many
lots of milk showing no bitterness.
Some of these bacteria form acid and
sour the milk; the more 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 rea-
son bitterness has been most frequent
~ observed in pasteurized and imper-
tectly steriized milk
The few remaining spores terminate,
and as they are unhindered by the
presence of Tactic acid bacteria they
soon reach unusual number and the
bitter flavor appears.
hemic, persisting day after day. and
causing great trouble. This may be
due to some constant localized source
Of infection which adds each day un-
usual numbers of bacteria to the milk.
In some cases it has been found that
the udder of COW was infected. This
should be determined by carefully
cleaning the udders of all cows and
milking from each quarter of the udder
of each COW into fruit Jars or bottles
which have previously been cleaned
with boiling water.
In case one of these samples shows
WE'LL developed bitterness while 9TH
ers remain normal, it may be assumed
that the source Of infection is the I'D
der Of the cow. In that case 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. i
through some combination of circum
stances the Tactic acid bacteria ar,
suppressed, other. kinds become pre-
dominant.
The utensils, the milk room and thu
stable gradually become inoculate,
with these bacteria or their spores an,
each new lot of milk is thoroughly in
& pculated.
The bitter-milk bacteria may be on
of the new forms. In this event it ma
be necessary, after thoroughly clean
Ing everything coming in contact wit
the milk, to introduce some good sou
milk from a neighboring dairy.
In this way the normal fermenta
ton may be restored and the objection
able bacteria suppressed.
Ropy milk is, so far as known, in n
way detrimental to health. The ia
nous Edam cheese is nearly all mad
from milk which has undergone thi
fermentation.
Most people, however, object seri
pusly to milk with any tendency t
form threads. This trouble frequent
affects the milk of dairy day afte
day and is removed only by the mos
drastic measures.
Outbreaks of this nature frequent
occur in the cold months, because tt
bacteria of this group thrive better
low temperatures than the lactic-aci
bacteria which hold them in check ur
der normal conditions
In one case it was found that the.
bacteria were abundant in the dust
the stable. The trouble was remove
by thoroughly cleaning and whit,
washing.
In another serious and persistent gu
break it was found that the milk
1t came from the dairy contained fe
Or no ropy milk bacteria, but the
were abundant in the water tank
which the milk was held overnight
The small amount Of water occ;
.ionally splashed into the cans adj
I'd sufficient bacteria to make the mi
ropy in a comparatively short time.
The utensils and floor had becor
SO thoroughly impregnated with tt
organism that milk exposed in t
room or strained through the wi
strainer became ropy without contar
nation with the water.
The trouble was removed by tho
oughly scalding all the utensils, di
injecting the floor with S per ce
sulphuric acid solution and destro
Ing the organisms in the ice water
adding potassium bichromate-in t
proportion of one part to 1000 pal
Of water.