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MiatOCOfV RiSOlUTION TIST CHART
(ANSI ond ISO TEST CHART No. 2)
^ /APPLIED IM/^GE
1653 Eost Main street
Roches*!r, New York 14609 USA
("fil 482 -OJOO - Phone
'S - 5989 - fax
(=3 11 '73
Co BJt.t
BULLETIN 120 MAY. 1902
Ontario Agricultural College and Experimental Farm.
HITTKl: MfLK AND CHKKSK.
Bv F. C Hauuisox, PkoKKSSOU (iK I$.\( TKIUnl.uoV.
Diiiinjj the pa^t HUiimier ono of tin- It'iulini; cJiwse luctorifH of the
Province was very much tronhh-.l witli an affection known as hltfn- milk
which jrave a very unpleasant flavor to the ch. fs,-. The trouble was not
a new one at this lactory. The year before last it caused some annoy-
ance and loss, but not so much as last year; and even two years a.'o 'it
was occasionally noticed ; hence it would seem that the infection was in-
creasinjj from year to year.
J ?'"^ patrons of the factory could not account for the trouble. They
had been handling their milk the same way for years and had no trouble
until a few years ago. Hence some were disposed to blame the maker
Others that had no silos blamed those who had, thinking that ensilage
gave a bitter taste to the milk; and others again regarded Ragweed
{Artenanta ambroaifolia) m the cau.se of the unpleasant flavor. None
thought that the true cause might be a micro organism,— because neither
patrons nor makers have yet begun to realize the clo.se relation of bacteria
to dairying in all its branches.
This and similar troubles are constantly on the increase. J. W.
Robertson (I), the Canadian Dairy Commissioner, states that durincr the
first year that the creameries in the North - West Territories were operated
there were no bad flavors ; that, in fact, it was difficult to get proper
souring ; but now, not only does the ordinary souring progress in the
usual manner, but also a number of bad and "ort " flavors are met with.
In Eastern Ontario, we have records of Rusty spot in cheese ; and in New
York, a number of troubles, such as Sweet Flavor in Cheddar chee-se and
Fishy flavor in milk.
Jud},'ing from the varied complaints and the increasing number of
samples sent to the Bacteriolo<,'ical Laboratory for examination, it is evi-
dent that a serious condif n of aflairs exists, and that the methods of
handling milk, as practise.' n the average farm, must be changed, if we
are to improve or even m ntain tli<> reputation of our dairy products.
Nor should the improvejoent be confined to the patron ; for many factories
also need improvement, the commone.sfc defects, according to J. A. Ruddick
of the Dominion Department of Dairying, being bad floors and drainage,
cheap apparatus, and improperly constructed curing-rooms. These rooms
become too warm in summer and give rise to the so-called "heated
flavors." The chief defect from the maker's standpoint, according to the
[1]
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same authority, in a weak, open bo«ly in the checHe, due to insufficient de-
velopment of acidity during the process of manufacture.
I may also add that this lack of acidity not only cauitesopen cheese,
but sonietimen gives ri»e to bad Havors as well, for thf acid checks the
development of many injurious biicteria that may be present in the cheese.
In August, 1901, we were a^ked by a largo Western factory to con-
duct a series of tests in order to ascertain the cause of the bitterness in
the milk. During that month the factory had bitter milk nearly every
day, although it was very difficult to detect by smell ut the timo the milk
was dumped into the weigh -can ; but, in exceptional cjises, the bittomess
could V)e detected even then. The bitterness could be more easily smelt
when the vat was warmed up for setting ; and the odor increased as the
curd was heated. When the curd was very bitter, the top of the whey
foamed with small gas bubbles, especially when stirred.
The following notes on the making at the factory were supplied to
me by Mr. Stratton, the College cheesemaker, who accompanied me on
one of my visits :
Ci'LTL'RE. About one-half of one per cent, culture was added to
each vat at the time of comnn-ncing to Hit with milk.
Condition ok Milk. Most of it seemed in fair condition, but on a
few cans the so-called "bitter Havor" could be detected.
Settinq thk Milk and Heating the Cwrd. The milk was ready
to heat soon after heating up (average per cent. acid, per alkali test,
.182). The agitators were .set in motion soon after the cutting of the
curd; then, after the temperature was raised to 98'', a hand ruke was
used. During the process of heating, the llavor became very prf)nounced
on all the curds.
Dipping. Most of the curds were dipped early. The whey w. '- • *
off when the acid showed about ii in. on the hot iron (average per . ,
test, .210). The .stirring was continued from 13 to 20 times, ace il
to the condition of the curd. The acid developed so fast on some
that it would draw out about one inch. Before the .stirring was com-
pleted, the curds .showed also a corre.spondingly high acid per alkali test.
Milling. Tlie curds were ready to mill in a little over two hours
from time of dipping (average alkali test, i.152). After milling, they
were washed with about eight pails of water at a temperature of 98^
Maturing and Salting. When freshly milled, the Havor is
strongest ; but there seems to be a permanency about the bitter Havor ;
and there is little improvement while the curd is maturing. The mel-
lowing down process is also very slow. Probably this is quite largely
due to the excessive amount of stirring required to dry the curds at dip •
ping time. In some vats the bitter Havor was more pronounced than in
others, and was occasionally accompanied by an aromatic flavor, or fruity
flavor, especially noticeable when one pulled up the cheese cloth to turn
the curds at the end of the vat. The curds at salting time had a fine,
♦Kn,^«..K 'p """"*,*"» HliL'lit. Trie curilN showe. a very hiirh add aII
pro(wce.lrt bitter ta^te in •. ilu ft- »> east like HpeciOH which
.,..£:,l;,iI:!l;;:r„ln;,7;;l;i':;:r\,,S,:i;;!;;:;i,;\;™-:!:^s;- ->
Ouelph, ami that " ^ h,? , ' , t, fZZ" """ •"; Pr" '"""■' "'
bacteriol»Kic,lly ,M„,pl™ „f the „ vp ,?!il ? ' "'"''■"'I'-'l to a.,nl,v»e
factory, to ascertain ir the" I, hternoi ' ™ ,■ L"'?, '»""'" »'' 'I"'
certai^in,Hvid„.,a.o'r«it vtr/SenerariX'Z "^ ""* '■"^''''='' "^
packed in", box aM " c„t tTth^l^jt Jv '^ ffi """■ • '^^T ""^ «••"■
condition. No Ixittles were bmk™ .Jj ^' '^^"^ ""ir?"! 'here in good
w
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u
■ i;
And at the villi of thiit tiiii** it wun uxainiiuMi for ^'hm, diifcHtion of ciinl,
aiui tluvor. Till) wort ciilturcM weif aUo inculHiti'd at .'{7''' ('. for 48
hourN, liiiil tli«;n fXniiiiiuHl niicroHoopifiilly for tlio prt'Hcnoe of yt'iiMtb,
The wort irt'latiiif pliiti'H wen- ki-pt at 20^ ('.. uikI, an th»' colonicH
devflo|)e<l. tlu«y wcrt' Ntudifd and, if iieco: . 'ry, iNulnted. In this way !>'•
Hniiiplos of milk, from as many diMt-rt'iit pnlMuis, wi-rc «>xamiiit>d,'Knd
yeaMts wt-ru finmd in !>7, in many chhi'h wvoral s|M'cieM Iwin^ prt'si-nt; l>nt
tlif pri'dominant variety was the one <;ivin(^ ri.-e to hitter milk, to which
I have j^ivfii (lie name of Tonilii tnanrn, or tln> hitter Torula. //. »«,/<",
H. Inrtm ui'nH/rncM, H- niihtilin were also prenent in the majority of
HHmpIo; and the following; N|)ecieH of hiicteria and nioiiIdH were aImo
«juite common: Oiilium luitin, Pi'nicUlutn ijlawam, J'roti'iin, Stiiuhitrn-
mtfCfH ({/n>oui/(M, the pink Torul ., and a niimlx>r of HpucieM that were not
determined, viz., yellow chroino^'enic forms, a red inouM, a CHpMiilated
bucilluH. various coc'.-i, various yeasts, a slime producing Imcilluw, etc.,— a
rich and diverse Hora.
In fact, the bacterial tlora was so rich that it was thoufi^ht advisable
to visit all the patrons, examine the conditons under which the milk was
produced, and endeavor to locate the habitat of the bitter torula. The
tarins of some Hi patrons were visited. Samples of the foremilk (or first
milk drawn from each teat) of a num'ter of cows were taken ; also of the
can and pail washings ; and, if the milking was done in the stable, a
sterile Petri tlish, the lower surface of which was smeared with sterilized
gum tragacanth, was exposed for about a minute to the stable air, when
the cover was replaced and the dish wrapped up in sterilized paper.
All these samples were then taken to the lalwratory where the ex-
amination was continued ; but, before dealing with these renults, we may
say a word oi- two regarding the conditions aino- ' the patrons.
CoN'DITloN OF Cows. The cows were in goo ; condition and ouitc
clean ; there was .scarcely a dirty i|uarter or udder to be seen. There is
very little low-lying or marshy land in the neiyhborhood of the factory;
and consequently, the cows are not soiled with dirt or stagnant water.
Conditions ok Stamle.s. Speaking generally, we must say that
the stables were badly lighted and poorly ventilated. The beam ceilings
were usually very <lusty, and generally festooned with cobwebs. The
floors were fairly clean ; but in some, the poultry had soiled the m-ingers,
partitions, and racks to such an extent that a heavy, close smell was
noticeable. Such stabler gave a very large number of colon Iwicteria
upon the plates exposed in the htable air. In other stables, swine were
kept alongside the cows: and, in these cases, a very objectionable smell
was present, very injurious to milk ; and the bacterial content of the nil
was usually very large and very undesirable. It is also to be borne in
miml that the air was quiet in the stables at the time of my visit. The
cattle had been out some hours ; and there was no disturbance c litter,
etc., such as there would be when the animals were brought into the
stable for milking.
5
dnth:^. llil"' *" the factory w,« Ht onco struck with the color of the
olothH, and an examination «h..we.l that th.< color in the c'oihH wm
due t.. a chromou. nic mould. Thin n.ould wan vnry abundant iucHUhlJ
air ; in fact, we isolated it fr..iii 20 .tahlwH
Bahn-vahI). On H«.v.r.il farfii«, th.' town were niilke<I in the vard
^ w In^l'^^^ .T " • "''' V. L "f conHtit,.te a Houi-ce of infection. eMiK^ially
Int^l I T"*^- **''.•* '^""TV ^'""•« t^"^'"" cunditionH were present
contained verylar^e n»mlH,rH of the colon I«icillu8. and //. lacUs ,.eL.Ves
Whkhe CAN.S ake keit The cans were kept in n.anv different
J S '? "•■."?'■ '•" '^''-y""'- ''««""'t an out Inliiding. Tder rL o,J
a ,ni k-Mta..d clone to the roal. or hv the Hi.ie of the ho. se. In m, cane
was therea projK.rly constructed n.ill< .hed. where the milk conl l" kept
nnik weroohcM. i.ft ,„ tl... han.-yanl osv,„i,ht, in h lavo.-al,!- sit a
i- the a!.Y.r,.t...n ot odors, as «vll as l,ac-t...m from .Iri. d partiHes ,,
laauiiru or dust which mi^rhr 1.,- Iloatin- arn.iii.l (.S.-e H^'ures I ■> a.i.i '{)
^';-^ 'T'OV OK Cans. The ea.,s ;,^.n...-ally in use hold ,i1.'„ut :{0 .ml-
10..S hey have concave l.otto.ns and -n.. si.U- seam, whicl.is not alwavs
. noothly soldered. ,, son.e, however, the bottom is convex : and ll,.se
latter ar." very much liarder to cl.an, ,is ll,.- whey is left in a ehann..l
around the edge, and dirt there cannot be easily re.noved by the Uusl.l
li
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V.'ry many milk piiilM iirw nUt v.ry IwPy ti»nKtMifl«.| with pn-Hoil Jn-
Htfttil of N(i|ili<n>t| HfHiiiH ami convex hutto'iiiN Tlif c^ '.h iihc<| hy tli<' pnt-
ronM wtT.' ijMimlly in jjikmI roixlition a- i.';i^iir<lH rii-.t ; l;ut fHiiiiirM purcliiiH-
injf cans Hliniild inMint tlmt tin* mhiii Im> »<i|i|i>t(>i| no that it piowiitM it
HiiKMith Huifnce thitt ••nil U< *>nm\y cIohiiimI. In t<Mi many ciiwh. tlio |Miint
of a knifi- mn Ik- insort.-l in th.f ill-Httin«; miMii, itml wiilnlmwn covi'ivil
with .olinif or «liit. It in imjiosNililt; to cluHn ii ean thoioiij^hly whicli Inin
thiH <;rave defect.
Methoi>h ok Cax-Wamiiino. After the chdn urn enipiie.!. they are
UHmilly»crul»l)«'.| with warm water OccHMionally Ho«la \h iiNed. and at Home
plawB, w<M»d iiNheH, the latter N-ini^ HomttimeH mixed with rlirt or wind,
which is apt to wratch the tin covering and permit the aci.l whey to act
on the iron. A iter the rinsinjjH are poiiruii out the can \h Hcahled with
hot water, poured fi-.»m a larj^e kettle ai-ound the innide of tli« ran. The
can is then rinv-d with thin water, which Ih left in the can until ir in uned.
or the ririHinjt water In poure.l out. In some case-, nfhr the mnliUnn,i\\c
caniH wipeil with a ra>.'.
Tlie objection to the Hcahlinjf in tlii.s manner U that the water i.s n>{
hotenouj^h. The umml practcu in to take the kettleful of water from
the houw to the place where the caiw are washed, and .set it on the^jrouiui
until the preliminary waHhinj^ and Hcrubbiii); is Ktii»he<l. By thia time,
the water, instead of lieing at a temperature of 212'^ K.. is about UK)*' F..
ami is still furth' r cooled when poured down the sides of t.ie c-iM caii.
The Hiial wipin;; dry with a rajt is a bad p.actice. as the cloth is sure to
be contaminated with Iwicteria, which are thus rubbed over an« I deposited
upon the scalded surface of the can. When the cans are finally scalded,
they should b.? tiirne<l bottom up. tipped to one side (facing the sun), and
left to dry in the air.
C(MH,iN<i AND Aehatiov OK 1HK Mll.K. So far as I could ascer-
tain, no form ot cooler was in useamony the | alrons. The usual practice
seemed to bo " dippini:." very often in an impure atmosphere, where bac-
teiial infection was likely to occur. A few patrons n^ed the " Kippea '
aerator, but found it un.satisfactory in warm we ttht-r. Souie kept the
milk in pails innnersed in a troiijrh of water ; but with no coverinj,', ex-
cept a wire sci^en to keep cats rnit. Kven f-.r lartje cans, this was thr
form of CO- ^ used ; and the milk was thus left exp i^ed to bacterial
infcctidii from the air.
Very few patrons know the dittVrenc.' between aeration and coolin;;.
aeration meanin!,' to them, in the majority of cases, c(M)lin;,' as well as ex
p.siire to air. Further, some chee.semak^rs in the past stated that cool
ing milk injured the clucse, or that it was impossible to makeyoodchecs.'
fnom »,..r.U.i ..,;iu 'I'l.:. :,i ..i i i V .. .. ". ,
fr
■om cooleil milk. This idea, proiimijra'ed before tlie use of acid cult
urc
or .>.tarters, ctill lin},'ers around many factories; ami it is <|uite difficult t
convince peoplj that proper cooling is far more important than aeration.
Aeration is certainly neces.sHry when the milk -i dirty .a- h is absorbe,!
|.r.,t,M.t..,l f,..,„, .1,,,,:' """"""• '"'•'">- ""■ '■■•MS ,.,.. t .1 „. „,.. ,,,,., „„., .,,.,, ,^,,^
The wi,„|„w8 ttiui .lours wito unproUct.'.! by fiv seiven^ (^m»,«
«f". ;., T ? ? . " *^''*' '""kii't'-rooiM won' put int.. a test tiil« o'
8
The utensils were kept in good condition ; and also the vats ; but the
curd sinks needed airing. It is true that they were well washed ; but
they needed to be sweetened by being exposed to the air and sunlight ;
and, as they are not used until about eleven o'clock in the day this could
easily have been done.
The cheese cloths were of a peculiar red color, especially where
they came in contact with the sink. The color was found to be due to a
pigment secreted by a mould, which was quite common in the mixed
milk, and which I subsequently found to be very common in dusty stables.
The cloths were well cared for, — washed and boiled ; but the red color
was not removed. They were in fact, dyed with permanent or fast color.
Of course, in this case, the maker was not to blame ; but the patrons by
cleaning and whitewashing their stables, could most probably have preven-
ted the trouble.
Causes of Bitter Milk,
Bitterness in milk is produced by several causes, which may thus be
classiKed :
I. Certain foods, such as, Ragweed, Lupines, etc.
II. Advanced lactation, especially just before a cow becomes " dry ".
III. Disease of the udder. In Mastitis -or intlamation of the udder),
the composition of the milk is considerably changed; and a bitterness,
or more commonly a salty taste, is produced, in most cases, this change
is revealed by the appearance of the milk, which becomes a watery, serous-
like fluid.
IV. The growth of microorganisms in the milk.
In the first three, the bitterness may be noticed immediately after
milking; but if the bitterness is due to an organisTn, the bitter taste
appears only after some time : and it is witli this cause that the pre.sent
investigation deals.
Those not interested in the biology of the I litter organism will please
turn to " Eflects on Milk," page 14.
Thk Biology of the Bittkr Organism.
As has already been stated, the organism producinu the trouble was
a Torula, which was found in nearlj'every sample of milk oxainined ; and
in order detinitely to characterise this organism, it will lie necessary to
give an account of its behaviour under ditf'eront conditions oF food,
temperature, etc., information of importance to the bacteriologist, and
thus necessarily technical, and of little interest to the maker.
HisroKiCAL Resu.mk. In 18U(), Pasteur (2; whilst workinu; on tin
theory of spontaneous generation, noticed that milk which had heen
boiled (lid not sour like other milk, but became bitter and containeil
butyric instead of lactic aeid. Further, he noticed that the orjianisriis
obtained from the bitter milk were different from those he observed in
to destroy them ; an.l the7steD bv In\^ temperature he wn.s able
tion from the butyric ^ ^ P' ^^ ''^P^^'ed the lactic fermenta-
same'J:tJLrobLn:;jJ.SLT.r^^ ''^'^'' "^^^^^^ ^ ^•*^— the
}>acinus"t:^A'^> S^^^^^^^^ cheese isolated a
presence of oxy.en. This or,.'::^':.t7'o:X^^
the ^Sl:^o^J^%Z^ /'.l.'^L^;*^— -« ^- to
Liebscher (7) wrS^rbitTer mi k his's t'^ ^rP^t^^r-
some days it putritied and thnf «„i!?k 1.^ i i.^', *"^ noticed that after
suggested the pos"ibnitv that thrnf'"''^ hydrogen was formed. He
form of ProternclgX '''"' '"^ ^^^'"*' P*"^*^^^^^ ^
niteif SS St'ti^bitSK^/isSd "^r ^!:j^^^^j^^^■ ^'- ^«fi-
ing some time, was not «; t? a chani f 7^ which had been stand-
bacteria, but thHt in such .nilk there wfr/.K ',*'"" '-^ "V" ''^^^^ic acid
the heat to which the milk was J;,»^? \ \ Wna which resisted
speciHc changes in the^n.X'.^reiS ^ bTt ert^r^^/r'^^^^
This germ, however, is n„t identioal ,^,;h ' :, V . Z*^ ^- '^'''2/^^t'«''-
Intler Uistc, a, thin acUl l,a, „f ifclf „ I™ i, ,J " h' I l'!;,"J"«'"l »
Juce.1 no biilvric «ci,l aii.n,,. tl,„ , 1,, ,1 . , i~ "" ''»«'llu» I'fo-
This oi-Sanism cm llcV , Hk uhh , ^ 1. '■," «"■""■" '" »'""i2«l milk.
10
'■i
When grown in bouillon, the odor, taste, and slimiiuss resembled that of the
bitter milk. The presence of butyric acid was .letermined in the culture,
and butter made from the bitttr ud k was rancid,— after two days it was
■' strong y rau'iil, and the t«Hte strong and burning"
This case of t.'onn's is noteworthy as being the first example of bitter
milk naturally experienced. Previous cases were u-uaHy as.sociated with
im| eifect steiilization ot nnlk, <lue to the growth of sp-re-forminL' oiLran-
isms. *"
Wiegmann's germ does not seem to have been of economic impor-
tance, as it was isolated from sweet milk, and Kruegger cannot be said
to have substantiated his statements by direct infection and subsequent
production of bitterness by means of his Pvotem vulqafiH species.
Hueppe (13) in his second paper referred the bitter ta-te to Mpnen-
tertcm vulyatus, as well as to B. hufyricun. He expressed tlie opinion
that bitterness was due to the production of peptones, and in support of
his opinion, cited the f-.ct that all the bacteria found in litter milk
belonu'ed to the chiss of peptonizing organisms (those that liquetied
gelatine) ; but he did not deny that there were biicteria which were
capable of producing bitter substances of a special nature. We must
also remember that there are very many bacteiia which liquefy gelatine,
but do not produce bitter milk, which latter is by no means a common
occurrence.
Bleisch (14) isolated from milk imperfectly sterilized by the Neu-
hauss-GroniwaM-Oehlmann's method a bacillus which produced bitter
milk. Peptone was produced. This germ formed spores which resisted
a temperature of 100" C. (steam heat) for six hours. It was probably
allied to the B. butyrieuH of Hueppe.
De Freudenreich (15) i.solated from a bitter cheese a coccus, M. cnsei
amari, which produced a bitter taste in both milk and cheese. It pro
duced acid and iiqiiefied gelatine, a rather remarkable combination.
Cheese made Irom nnlk containing a culture of this organism was bitter.
It produced peptone (0 8%); but the bitterness was not entirely due to
peptone, as de Freudenreich succeeded in separating bitter substances
which did not belong to the peptones.
The same worker also isolated from cream another species, B lifjiw-
faciens Inctis amari ; and fresh cheese inocidated with this germ had a
disagreeable, bitter odor. The germ probably belonged to the putrefy inu
organisms.
O'Call.ighan (16) found a yea.st which gave a sharp, bitter taste t'<
milk, forming alcohol. He stated that it would be injurious to butter-
makers, and still more so to eheesemakeis, although no' experiments weiv
made to support th'se statements. He named it Sanharotnyceii but Is,
but did not de.scribe it; and Beyerinck also gave this name to' a yeast Ir
found in Kephir.
Investigations at Guelph.
During the summers of 1899 and 1900, samples of bitter milk were
II
TORULA AmaRA
.ro^'"r:t^^^^«;^f ,^^-^^^;eh^ taste when
face of fruits and leavZ as tCmrs''^"^"'^^ ^'^""'^ «" ^»»« «"«-
by Cavara (17) on the pedine s < fTn,;^'!:.?'^^'^^ ^'^"^^rf'^' *»""d
coveredbyGronlund(l8)onthefrnitnf //V ^"^'^'f«';«»^V^'^« /^'ci.s. di.s-
present on the fruit of the MahVa /«,/• f ;7',"-^"''^ ^"'' '^ yeast
from the Howei^ of which a *troni^r "r"^'/-''/' *-• '^ Sapotaceons'tree
examine the trees and frui^near wJ.i .7 ' "'•/."'' '' ma.le-led me to
from th. leaves of certain spec?e, of mant'l'"'"? TT ^''^ "^^P^ ' «"d
with the species .o frequentirSuJ in7£ I isola ed a torula identical
tornla I have na.ned ^oS .m rm '"'"' '^"'^ ^^^-^ashings. Tnis
liitt.T Tonila iT„r„/„ A„„n
■"». lA'it/. ()<■. 4
moisSlnb^. ^^e,,^:;;;;^,^;;---^^^ ^V-^ l^alD i„ Boettschers
'Some are as lo„„ as 10 » ImMh ^ m shape, a.ul of varying size
After some day.s'''<rrow iJ^^ ^iv.raj^e hes betwetm 7.5 a„d9.0;'
the cell wall so';ne^wLt l^se it" L^n out'lin ''"^ «'''/ ^"•^" "^'^"«'-- -"^
at the smaller en,I of the eel Kn "f , ^"I'^o^^' """'^"^^ ^""'•"^d
usually oval, but round rnre^.-shape Li, n^''' ''^ S" ^■'n^^^ ^«"« ««•«
iy. ^n short chains of three or-f^^iXln^lXmpJl^^^^^^^^^^
FT
12
On beer-wort agar at 37" C. the colls are somewhat larger, more ir-
regular iu ahape, and contain numerous small oil drops.
Spore Formation. No spores are formed. Spore blocks made from
young, vigorous cultures, kept at 20", 23, and 37° C. for 7 days, and ob-
served at short intervals, contained no spores. Cultures in wort, peptone
whey, and yeast water never produced spores at the temperatures given
above, even when all conditions prescribed by Hansen were presnt.
There has not been any formation of spores in old cultures, some of
which have been under observation for four months. Thus the organism
is not a true Saccharomycete, but a torula.
Wort (11.2 Ball.) In two days, at 25° C, there is an abundant
growth ; the liquid is slightly turbid, but there is no pellicle or film On
shaking, numerous small bubbles form a deep layer of foam on the sur-
face. In four days the liquid is clear and bright ; no pellicle ever forms ;
about 2 per cent of alcohol appears. In cultures kept in small Erlenmeyer
flasks at 37° C, a "yeast ring ' forms ; but, at room temperature, no ring
develops, even after two months' growth.
The reaction of the wort, after fermentation ceases, and the carbonic
acid gas which is driven off, is very slightly acid. In whey containing 1 per
cent, peptone and .25 per cent Niihrstoff Heydeu, the growth is very simi-
lar to that in wort. There is an active fermentation and the reaction of
the medium afterwards is slightly acid. In whey which has been boiled
or filtered, 3 per cent alcohil forms in 8 days at 37" C, and no trace of
.sugar is foun<l. In yeast water, there is a heavy deposit ; the body of the
liquid is clear and brii/ht, and no film is formed.
WoHT Gel.\tine. In two days, at 20° , piii point colonies, about 0.5
m. m. in diameter, are visilile, the surface ones being slightly conve.x.
Under the microscope (2-3 obj.), the colonies are dark with entire edges.
In four days, thev are round, greyish white, shiny, and from convex to
capitate. They are not at all characteristic.
Bkef Pkptone Gklatine. Colonies in this medium are .soniewluit
smaller, but resemble those in wort irelatine. In four days they are still
similar to those described above, but under the microscope the edgf of
the colony is slightly rough.
WoHT Gi:i,ATiNE SncH. In ten or twelve days, the line ofpiiiictui.
is beaded. The beads are distinct, and of considerable size ; later (20 ti
30 days), a dense, spiny growth radiates fi-oin the bea'is ; but the projic-
tions are not sutficiently long or branched to justify the term arborcscii)'.
They may Ix' called echinate. The surfa<;e growth spreads from 10 to 1 •
m.m., is umbonate, wa.xy, greyish white in color, but of a light hrowii
shade towards the centre.
Wort (Jklatine Ma.ss Ci'Lture. These cultures were made liv
placing a drop of wort culture on the surface of the gelatine The snitac
growth spreads over the entire surface in 30 days. The edges aic tliiii
and slightly rough. The centre is elevated, forming a plateau, which i^
13
^r^^:^^!^:StZ^^' ^^ '' •" ■"• i" ''i-'ete... The
gelatine to a depth ot" 4 mm ,^1 erv' '["''/"'^t*'"''^, 'lownward into the
taons deu^arcate'the line o cont!^t U ween'Tl ' "■*'"' r'"' ^"^''""^t^ P'«J^'C-
days a slightly nus.-d. np Jdlnr^,;^ i^,;"!;-;^ ^ "^ ;f C- and in three
i8se.^^Mdneh becomes nm.v uZ^Wj^iii,^^^'- '" "^^-'''^tenin. .rowth
<jays!;^'\,j::^;l;;;^- ^^^^^^ -n th.e
dull appearance. In seven .lav. there it n u" ""* ^''"' P"*''*" ^'V its
cent «cch.ro,e, „ ,™*„f JL fors'S"';';."'''', "">, '"l-'i""" "f 6 per
u...eJ;x°'S;rt„s.;t;'2i,/ »'< "- ?" -''■«-• -^
fllm, the body of the li.,uM rS ™ ^ , " f"^'"^''- There , „„
heavy deposit. The ,ug, rU "overted «=!hli^'"''' j'™"-' l-"' thore i, a
contain na one per cent, peptone Is MrV.Jja-? ""'"i"™" '» l»"»lon
cent, salt, and X per cent saShartf „. • ^"''"'"f H».vden, five per
re.s,nble, that in^h.ro«.f^lS'Se? " ?"«'■"='<''»"•' 'he grow^lh
t'T^r ^ShtSe'of gl ta™vrdr.ttS "'^-.f*' »"gl"co.*,
turbidity, but a heavy dejmit " " "^ ' ' ''ere is no Shii, no
ConiJriS^.t'^ tllt^Z^^Zr'^- "-^' «"«!> i» -nilar to that
ther..i:pdelt^%,.r'bi,ftri:\r':°;;,str^
hlin, and 90 per cent, gas is tor d ° '"'*^' ^'"re '» no
« f!^"^'^-:i^X£s;s'^:t:i^':;,i^-T''r»
rer„i^:n^,^ih™i,s?;^,r-:^r"" ^^ -- --.-S^ult
hoav?e"rSri:';5::;r,SL",° «"" '^ '"'■"""■ ""' "- =-<>" .1. i» .ii,htiy
-nght'ir of ™^is ts°"^Th"e*x"^nS,r ^T T> ^■•"°»'
there is a heavy deposit. '"'= '^^ '''l"'d "s clear, but
i i\
14
Effkcts on Milk.
I i
Milk. In sterile milk the bitter taste can be detected after five or
six hours (growth at 37*' C. In 14 hours the taste and smell are disagree-
able and strong. The odor of cultures a few day old resembles plum
kernels, and the taste is very unpleasant, bitter and astringent. In 10
days, at 37"' C, the milk is sligntly thickened, slightly acid, and the
odour and taste are both pronouncea. A slight, aromatic, ethereal smell
may also be detected, but it is frequently masked by the bitter taste.
There is much gas formed.
Culture gives the biuret action, indicating the presenc of peptones.
No butyric acid is present.
Effects of Drying, Antiseptics, etc., on Tobula, Amara.
Thermal Relation.s..
(98.0- F.). (Srowth at 25*^
growth
The optimum for growth is about 37° C.
C. is abundant, and at 20" considerably
occurs at 5° C. (41° F.), and none at 48''|C.
slower. No
(118.4* F.)
The thermal death point was determined in triplicate, by Sternberg's
method in whey bouillon :
Ten minutes at .SG" C. : living.
Ten minutes at CO'' C. : in two tubes, no growth ; in one, much
growth.
Ten minutes at G2* C. : no growth, all dead.
A moment's exposure at boiling temperature (98.5" C in Guelph) :
growl h.
Five seconds at boiling temperature: no growth.
Ten seconds at boiling temperature : no growth.
As this Torula was found in the can washings of nearly all the pat-
rons, a practical test was made to see if the ordinary scalding with water
at about 200° F. was sufficient to kill it. A 2.5-gallon, straight-sided can
was thoroughly steamed, and then rinsed with a culture of the bitter
torula. At the end of twelve hours the can was cleaned with warm
water and a kettleful of water at 200° F. poured down the inside and
then well rinsed, and the water poured out. After this, the can was
rinsed with sterile wort, which was then collected in a sterile bott'e, and
incubated. In 12 hours there was abundant development of the Torula
The amount of water used for scalding was 3 pints ; and the experiment
was afterwards repeated using 12 pints, but with similar results, the
Torula not being killed.
Effect of Desiccation. Cover glasses spread with a 24-hour- olu
culture were exposed in the open air to dry at a temperature which
varied from — 15° C. to 5" C. A cover glass was placed in whey bouillon
at the end of every 24 hours. For the first 7 days, growth occurred in
all the cultures ; but on the 8th and following days no growth occurred.
Effects of Antiseptics. A 2 per cent, soda solution at 56° C.
15
""nutes. ^ ' P*''^ ^'^Qt- solution killed the Torula in 6
Action op Acins Th« j,.* • x-
Ie«8 thaa that in the control Es " '"" '•" "^""^ -"-^^^t''- «iightly
. (•») Lactic Aeitl (1.2 dit o^>^^t I \f
th.s amount of acidit^. thL irtheTom^rS ZZ' "''"" '" "'''"■•- ^'^^
(4) Lactic aeid (2.+ ner r,mf > -n • .'
k'fowth than in the control tul"s'' '' ^ ""''''"'«nt deposit, and less
Ekfects of Acid Whey on Torula Amara
■1
h
16
able importanco to wcertain whether or not the bitter flavor may be con-
trolled in this way A number of experiments were made to determine
the effect of acidity on the bitter Torula.
In the first sericH, acid whey, containing 1.08 p-r cent lactic acid,
was used, and the vigor of growth was detennined by the amount of fer-
mentation. In such a meuium, 50 per cent, gas was formed. The con-
trol culture in onliuary whey gave H5 per cent. When neutral sterile
whey was inoculated with the bitter Torula and B. acidi lactic! together,
70 per cent, gas was formed. Acid whey (1.08 per cent.) simultaneously
inoculated with the Torula and the lactic acid bacdlus gave 48 per cent. gas.
The.se reault>4, taken alone, seem to indicate that a considerable
amount of acidity somewhat prevents the activity of the Torula ; but I
subsequently repeated the above exjjeriments, using the same Torula ;
and, after repeated transfers in whey, it gavt- a more vigorous fermenta-
tion than originally. With this culture in fermentation tubes contain-
ing whey peptone bouillon, kept at H?" C. for 48 hours, I obtained the
folio wing results : —
Torula amara 90 per cent. gas.
" 88
and lactic acid bacillus 90 " "
•< « " 87 " "
Whey and skim-milk mixed : —
Torula 93
Torula and lactic acid bacillus 94 " "
Skim- Milk. In this case, the lactic acid bacillus coagulated the
milk and formed a solid curd, which shrunk and adhered to the sides of
the tubes ; but the gas forced the whey into the open arms, leaving the
following amounts of gas in the closed arm :
Torula 94 per cent.
Torula and lactic acid bacillus 92 " "
II « II II « 89 " "
These more extended experiments go to show that the development
of acid does not hinder the growth of the Torula ; and the results are in
accord with what we know of other yeasts. For example, an aciditicii
tion with lactic acid bacteria is used in distilleries to prevent the growth
of injurious bacteria ; but the amount of acidity present in the mash,
about 1.1 per cent., does not prevent the subgequent growth of the yeast.
A final experiment on the influence of acid and temperature on this
Torula was made by growing the Torula in whey containing 1 per cent.
17
Uctic acid, at temperatares of 20", 25«, and 37o C.
Avwimt* of Two TeM*.
8ijilioan»ri«r ....
NiM hoan kftor
Twelve boon •TiOT
»»0.
2 "O,
3
1
A
4
5
16
S3
390
«7»C.
With the optimum (or best) temperature (37o C and iiRfiov\ ♦»,
Duclaux (20) obtained a lactose fermentine veast from m.lt ™i,- k
same one as he had found ^ ' "^ ^^'°"^**^ '* ''*« *^«
bXlauttndTdrer "'^™^'"'^ ^^^^^^^ '^^ specie^ descriS,
veast^bi^^W ^h!? *°.^ Wiegmann (25) also described lactose fermenting
yeast, but they did not describe them sufficiently for subsequent recog?
2—120
i '
18
Beyorinck (26) in 1H99 iHolated two yeiuitM, one from Kephir, which
he named Sitch. Kffir, ami one from Kdani cheeHu, Such Tyriomla which
fermented milk nu^^ariuid prothiced alcohol ; and he further iHolatud from
them an invi-rtive en/.ynie which he callt'd " lactaHe ", which he found
had the power of inviMtin^ the milk su^nr, anti cane HU>;ai' hut not
maltosf.
TluH concluMitm waH.howi'ver.coiitmdicted hy SchniirnianH-Kteklioven
(27), who was unahle to invert milk MU«ar with the enzyme " lactase" ;
and afterwardn de Freudenreich (2H) came to the Hiiine conclusion.
Bochiocchio(2'.M has aUo inolated a top fermenting yeast lr(<in (inina
cheese, which produceH blisters on the cheef^c. This form cnaijulates milk
with partial jwptonization, and pro< luces an a;rreeahle foaming heseragu
when jjrown m whey.
Jor^fensen {.iO) inolated a true Sacchuromycete from Kephir, which
produces alniut 1 per cent, of alcohol in the course of .S days. This Hi)ecies
be named S<ieh. frugiltH, on account of the feeble powers of re8i>tance of
the cell wall. It pnwluceH oval spores, which are sotin set free. So far
as I am aware, this is the cmly 8pecie.s of lactose fermenting yeas., yet
discovered which is a true Saccharomycete.
Duclaux (.')!) who reviewed the lactone fermentin}; yeasts in 1900,
came to the conclusion that the only three yea-sts which fermented Huijar
(milk HU«,'ar) were those isolated by himself, Adametz.and Kaiser. Those
subsequently isolated are either insufficiently descrilted.und consequently
one cannot say whether they are new species or not; or else they simply
assimilate the lactose and burn it in contact with the air.
The Torula amnnt ferments milk perfectly, even when oxyjjen is
not present. Cultures were grown in whey lx)uillon in an atmosphere of
hydrogen, and the sugar of the medium was fermented. In ordinary
whey calturcs, the sugar is completely fermented, as the following experi-
ment shows :
Whey containing 37.65 grams of sugar per litre before fermentation,
gave no traje of sugar (Fehling's .solution) after eight days' growth.
and the fermented solution was found t< contain nearly 3 per cent of
alcohol.
Kaiser suggested that certain of the lactose fermenting yeasts niiglit
be of economic nnportai.ce; and on account of the complete ferm<'ntatioii
of sugar by the Toruln amara, it might, we presume, be u.sed in tin'
manufacture of alcohol from whey.
Bitter Chee.se Exi'euimentally Produced.
A peculiarity about some of the bacteria that produce bitter milk i-
that the bitter taste disappears when the milk is made into cheese ; Ijui
the Torula amara f)roduce> bitter milk and bitter cheese also. We mad.
several cheese, using cultures of the T- ula, and the cheese thus ma<l<'
were very bitter.
The cultures used in the first experiments were made by breakiii :
ContH,„„.| H variety of ,„icr., or^auiZ. n Um" •''"" """""' ""^'"••'•y
r«t.o .. one another hs w„„|,| Tt ; ' w t ;•'' ';' 7"""^''"^ t'"' «««"«
of thiH culture whh a.l.le.| to I h^ 1^1: nf •■' /''''^''lA'" ^'*" "'"n.-lH
nimut..8 before M,,ttin-. ' '" '^ "* """< »*"•« '"'ft in it for (J5
v^ry fust. an.| hn.rn.on! tt'in'fi,!.*'nrV'^''^''''*''' '".'* «♦■«"•« "'.Ih worked
o nulling an.I .s«ItinK-(,.fV "I «. ' ^ r'/V.""^ "» -'•' Pr-ent „t tin.c^
Thn cuni w,is so.neihat «l v , .1 . . t ^'J Tl' 'V'^ r.-.p.ctively.
nmk.n;^ an.I .snl.se.,u..ntly wh'.n .. ' '" '"'' '"'"'"' t'"' tin.e of
tical with that of the chee.se f, . , Tl'' ""' "«^'"- .^"^ "-.t ai.solntely i,|en-
to be wo...le,e,l at w! en " .^t . 'C'i^/'^'^^'-''^'^^ »^"t thi.fi. not
one another in the exp.Tin.rnts w s , /i i. r '^'" '•^'''" "••^•""•••''s to
the onJnary factory Conditions it e^.! ''^' ^'1, ^'^-''^'io un,ler
waH bitter and diHaJreeable and th an.. '^ .."*"'"• * '^^ P'""''"^^ """'e
vats of the factory ias aiwavlnris^ af«»t"Ht.c Havor noticeable on the
The sc<.nn, ^i^ thes^Se^ra.^ lolfir'" '" ''^' ^*-^^-'^-
Cheese No. I. total score... ^-y- Points for flavor.
•I " o' .. • • • . 74. " <>
^- " •... 76 •■ .. •
*• 66.
BAt^TEKIOMMilCAL DaTA.
Max. 40.
. 15
. 22
24
20
bitter t^rnir'iJ^P"""""- "'"• """• '»<■ P- "on'' of a cituro of the
Age of Cheese.
7 days
28 "
42 '
71 •
Lactic Ati.l Bacteria,
•'er Kr«tii.
150.000,000
28,000.000
11,')00.000
«64,00o
Bitter Toru|».
Per (fram.
72,000,000
19,000,000
.'l-i00,00()
388,000
rp,, . , -.,--^ ;i88,000
Score ttt, iTo'^rifo'" '"'°''" '" '"" ™J- •'i"-""- -l-irable.
Cheeae made *" . ioh, iomi f,
bitter organisni U8t ry lit e add d.? .P^'"/?^ «f ^ «»'t"re of the
ry Uttle acid developed during the making, but
M
so
.495 per cent, wm prment at time of milling A ntrong bitter Havor and
aromatic "uppte {ramace" odor were p<>rc«ptiblo at the fitne uf malting.
RtolOkMMb
LmIm Aeid B*.'Ur<«.
Billar Tnvnl*.
Ptgnm.
Pvr «nun.
7 daya
119.000,000
85.000.000
20 ••
65.04 tO.OOO
7.500,000
80
61.000,000
B.HOo.ono
42 "
43,00(».000
l,(iU5,000
Score for Havor, 15 out of 40. Total score, 59 per cent
In order to Htudy the cheeite made at the factory, three were brought
to (Suelph, one of which wan placed in c«dd-Mtorage at an average t«'m>
perature of H0° F., an<l the other two were put into the onlinary curing-
room. The cheese exhibited a fair sample of the trouble complained of
at the factory, — they were «|uite bitter.
' ^ Cdil Stomffe Cheese :
Ar«.
liMtto Aold BvcUri*.
BltUr Torala.
Ptr grain
Per gram.
S8 daya.
342,000,000
3,200.000
42 "
271.000,000
' 70,000
90 "
48,600,000
162,000
[ Left in the ordinary cunng
•room :
No. d Dsyi.
LMtio Aeid Baoteri*.
Bitter Toral*
Pcrxran)
Vttgnm.
28
69,000
960,000
Oct. 21. 42
38,400,000
800,000
Dec. 4. 90
5.184.0(K)
hat. fhn rotriaorAtrnr
58,000
pKo»uo ivaa aitr
flavor to the cheese in the ordinary curing-room, although both were
made from the same vat.
The bacteriological resultH show that a larger number of yeants wen-
present in the cold-storage cheese, and the number of acid bacteria pre-
sent was alsu greater. When we take into account the proportion be-
tween the acid forms and the yeast, wc notice that in the cold-storagi-
cheese the ratio at 42 days was 1 : 1 47, and in the ordinary curing-room ,
1:48. At 90 days, it was 1 :300 and 1:90, respectively. Thus the pro-
portion of bitter yeast to lactic acid bacteria was much greater in tlu
cheese kept ii the ordi..arv curing-room ; and this may possibly account
for the difference in the flavor noticed by the judges, although the re-
frigerator cheese eould not be called good, as the bitter Havor wa.s quiti-
noticeable.
To some, however, it may seem that the number and proportion ol
the bitter torula to the lactic acid bacteria was out of all proportion u>
the effect produced ; in other words, that there were too few of the bitter
We
t4)
'He
SI
r.t::,;::;ea:;:::;'.';,:;;r;r,^^^^^^^ :»
lactic nci.l Lacteriiun ,u ,1 J, L! "7 «<>»""•"♦ hm |„r;;.. .iHtlie
BlTTKH E.\I-KIII.MENTS.
UHcd and the cream wen ripene.l at 22" C (70" F » for 18 ».,««! ti
rinened'wiM.T'/' 1^"'"" ^^'' '"^ "^" P"«teuri^e.l cn-an, (IfiO- F ) ,va8
utes^ fi J.'. I^ .leve oped. Ut the .sample churned easi t in 'S ...in-'
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tfnnl.L. f« . 1 -i^ . ' "^""/^'ilU'JI IS not (lohf, t It If Is (JaiU'cr fif
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cases, the^^ors. .sCchlol, "e^' we^' ^1)' wWui; *^?'' '"-'^ """J^^'- ^^'
or poultry. In such cases ih^ ^l \l • , * "" '•'"PP'''^^* of catt e
in large numbers: and the R^-d Mould o?uV''"k"''^ were usually present
made; was found fnlM stables A '' '"^'"t.on has already been
the bacterial content did not seen/ rwar.wfVi'*'^'^'^^ >nade. as
Thefl. acidi i«.<in(Esten) atTsoLsir L • "t*"^ »" ^e«tigation.
were isolated from the S-nfilk or tir.f . -iP*'"*!. \*""'«''^ ^''^^^"'^
In no case was the Cter T„r i « - J ^^ ^"^' "* "^''"^ * ^^'^ ^o^'s-
Colon group "'* P'""^"' "^'* '^"3^ representatives of the
facto;;jr^:2nrsitnrcHttT:je«S '-rt *•-'- ^^^^
proper places for keepin-' the milk Th . "*-;" '"^'^^ *« P^'o^'de
in thitn "vSsSs^re.t"?e;v n'r' ''if, 'T' ''r'^'y «^ ^P«-- fo"nd
The Bitter T^ru ^;a: isenfin Xaml 1^ -T'"^^'*^'>'^'-«-
the farmer did not dra^ thrwl" v iZ'^^n hi '7 ' ^"'i '" °"« "^' ^^^^^'
HXe
some, very few torulae Wf
- . '- 7 '• *" -""lit:, vciv low lorui
they existed in enormous numbers. In samp)
vats rnora <ir/>..,. 1.. .. 1 . . '
re present ; in others.
^ats, there were lartn
i«ms earri
The
ied back in the whey b
•e numbers ; and it
V may ,„ fact be described as endemic (produced by or depe
es of svhey taken from the
evident that these of;;dn-
on.
ndinir
came a permanent source of infecti
26
upon special local conditions) in this district. Hence, even if the cans are
washed and sterilized, there may occur conditions which will produce a
recurrence of the trouble.
The chee.seinaker of the neighboring factory (who washes and ster-
ilizes the milk cans in the factory) informed me that on one or two,
occasions during the summer bitter milk was delivered at his factory ; and'
he added " we should undoubtedly have had serious trouble, had'it not
been forthe fact that we wash and Hter'dize all milk cans in the factory."
In addition to the bitter torula, the Colon group of bacteria were
well represented ; and they are most undesirable for the maker, as they
give rise to gas and disagreeable flavors, and in colored cheese produce
mottles. Certain bacteria belonging to the B. lactis aerogeiies group also
produce a somewhat bitter taste in milk; and these add slightly to the
bitterness produced by the Torula amara.
A bacillus producing slimy milk was also occasionally found in the
can wa8hin;,'8 and stable air, a fact which shows that bacteria of this cla.s8
are rather wide-spread ; and, given certain conditions, an epidemic of
slimy milk may occur. Nothitig more concerning ^his germ need be said
in this connection, as the habitat and characteristic-, of slime-producing
bacteria will be the subject of a future publication.
Remedial Mea.suhes.
The inquiry into the condition of the stables, cans, pails, etc. of the
patrons of the K factory together with the bacteriological evidence
above related, show that certain measures should be taken in order to
remedy the present condition of affairs.
The dominant note sounded at the recent Dairymen's Convention
was bettfr care of milk ; for unless this care is given, it is impossible for
the butter or cheese-maker to produce a prime article. According to
many speakers and writers, the time has come when contracts should be
majde between the milk producer and the factory executive ; and these
contracts should contain provisions fur the exclusion of fowl and swine
from cow stables, the care of stables so as to avoid the accumulation of
dust, cobwebs, etc., the whitewashing of stables twice a year, cleanliness,
in milking, efficient aeration and cooling, proper places^ for keeping the
milk, the delivery of tlie milk at the factory at a certain temperature, am I
the proper washing of utensils. Should these improvenionts be made, I
am sure that the results would surprise all ccmcerned : and tiie little e.xtm
care involved would he amply repaid by the higher price of cheese inade
from milk handiecl in a careful, sanitary manner ; for it is well knowi
that buyers discriminate and place considerable emphasis on the nputn
tion of a factory; and they would, we think, quickly notice the merits < :
such a system as that suygested.
In order to get rid of the l)itter Torula at the Iv factory, n?i '
improve the genei„l conditions imder which the milk is produced' ui-
are kept befon- awl after the n.ilk
2. The cans. pai)s, and utensils.
3. The control of the temperature.
ispn?inirtKer'""'"^^'"'«'^--
stable, are «'rrSe.i™ble'"'^;:™.iiv'"tl;7;" ,""• "7 "' "««' "' "■•
^. *ai„i„, „,.„ .,, _'r'L';;' iix Ei-eSLt^ii""^
Stables should be kent oUnn f^. e
accurnulHtions of du.t).an5 be white;a;h:..rLr'''''' ^'"''^ •''^^"^^h and
and apain in the sprin-r when theooZ . "'*' '' ^^'"■- '>"«« •" the fall
wash should be mJde ?ro, esh ^^'^1^,?;; ""' IT''''''' ^he whii
the consLstency of cream should be ijrJr«*"?u'''"^'.'' ^*«^^ «' «^^"t
^J and applied by ,„ean.s of a ruT or oH ^'"'""^'^ '^ P'^^'' «f «^k-
later ««««. tvvo or more applica ,", a e n^i "' ^P''^rP"""P- '^ ^^e
molasseH, ni.e, or Portland cL^n Sed t,"T, ''l^ll """^ *'"'«• ^ little
adhesiveness. In ca,so disinfec-tbutthouXfo^ ''"''''' '''""'''' '^e
^.^acKj^u., be used in t^^^ pr:;:^':,^Xr^^^^c^
creasit;:::^:;;;^^^^^;^:^--- ^^^ctenal infection; but it in-
of the stock. ^ '" '*'''''^'' *''"'^ ''"-^ctly promoting the health
The Care of Pans Pah« <t„,..
cult to clean properly thanclns m 1. I ■"'' ''''"• ^'"^^'"^ '« »«"••« ^iffi-
Ht hand on the aVer/^e Cr Vo^ mo ?'"'"'"t "'f •/''*'• '^' *"««''ities
>"ay scrub the can. .she will rarely u • 'l ''' '''"^- "'" "^^'' ''^'"«owife
tl.at it will be free fro„. bacteSli a . !•'""""» '' «" t'^oroughly
u-d. and it is effective i„ imov , n...« ' f "u "V'*^"''' ^'^ eoinmrndy
;t has v..ry litcle Kernncidarv: ^^ 'S^liu^f '""" f "'''■^ ' ''^
"ttle use a.s a -ennicide. The fina so. Ml, /. P"'" ''^"^ ^"'"tion is of
-;,v boilin. H.u.-, is in.nfficiluc K' '^ ^"/'' ''"' ^f ''• ('^"•' ^'^nnot
"f the can and in the crack .n,l or io k' "'"' "" '^'^^ '"'""' ^"••«"*'^"
"'" far.". Hence tlu- prop . • Lv f o •^' ''"^' '^ "^'' ^^•''"'^^>'-' «"'
-l-re all appliances arJaUa,Hn^,.,m';r""^ T'^l'^ '"' '^'' ^"«'>'-v.
I'"d't'ously. So far as wo oa s . '"' '" T'"^" thoroughly and .k-
I""-tant O.K., towards tho rem v^ o \ 1 ^: ^'^'P' '^"•' '-^ ^'■'•V i"-
■"'d "thor i„inr,ous or.,,nisn I . .i,'" '"""^'' ''""" ^'''^^ '"■"^''- '''""I't
^''r;//..,/ ,.ej!on. th.y C he ;^o M ^''?'-""^''b- wusf,...| and
-!', see to it, that oU . .,„ ';?•,,•, r"" '"'" 'if t'"' t-'^^t'-T insist,
-'k, (Hwash and.scn,b :S^^^^^^^^^^ * - ^•■-- -Pplvin.
•ou„ni_y (and occasionally .scour) all pail.s,
II
L
28
strainers, dipptiis, and other utensils used in handling the milk ; (2) rinse
all pails, strainers, dippers, etc., thoroii},dily with hinling water iiniuediHtely
before using ; and ('^) rinse the cans out thoroughly with hoilintj water a
few minutes before puttin-.- the milk into them.
The practice of carrying ordinary, unpasteurized whey in milk cans
from the factory to the farm cannot be too strongly condemned. So long
as it is done, .so long will there be trouMe and serious loss from undesir-
able taints and flavors in milk ; and the surprising thing is that gwd
factories tolerate the practice. Let the whey be taken back in - -an
kept for the purpose ; or, if that cannot be done, let all the whey be
pasteurizeil at the factory by using the exhaust steum from the engine.
Utensils should be cleaned at the farm in the following manner :
First, wa.sh with water ; then scrub well with a hot soda solution, using
about two per cent, of soda (powdered concentratetl ammonia may bo
used instead of soda) ; next empty out the soda washings, and scald with
I
A single germ
Progi'iiy of 11 single germ in 12 hours in milk cooled with
eold WHter.
Trogeny of a single germ in 12 Ikjih-m in milk allowed t.
cool naturallv.
Fi«!. 6. - (Showing; the ertect of cooling milk on the growth of limterin. The lienetirial
results of early cliilliTig are manifest. (.After Kussell.)
boiliiig wntar: lastly empty the water out and allow the can to drain
dry. Provide, if possible, .some kind of cheap rack, to .set the cans on, at
an ang'e of alwut 4-5 degre s. On .such a rack, the cans will drv mit
nicely and will not be much exposed to infection from dust, falliin:
leaves, etc.
Do not, on any account, leave the water in the can ; and do not n-f
cloths or brushes in the Hnal rinsing with tlie boiling water.
Milking. The cows, before being tu'iied out in the spring sliniil I
have their flanks, udders, and tails well clipped. If before milking. t!i.
udder of the cow is rubbed with a damp cloth, the germs which m--
pre.sent on the hairy coat of the animal are prevented from falling ■ i!'
into the milk pail, as bacteria cannot leave a moi.st .surface. Milkii;'
19
If they Hre not so cL-^fVl^el"^^^^^
neglected cloths are an .mdoubtedl^^ oHntctbH ''^^"'^ "^•'''' -
of the bitter ToruIa^SS^he^,! o:i;!,"-^;, ^rr^f"- «« ^he^growth
of a single germ : ""wing ngnres show thu rate of growth
64" F. 4 ,. "• '^''"- ehrf.
40- F at thrfanfand L^Xn ':i '''^ ""'k Le cooled to
it shall not be more than 5?= F '\he "hW ' ''' city establishment!
ordinary factory practice : but if the milk^w, .1 '''^ P^'^'^y *"« low for
the farm, or to a temperature sav two «„. T^^'^ ^^«° *» 60 F. at
supply, it would be a^eat b^neTt ^ ''' "^^^ ^^*^ ^^ ^he water
constr^fd^^^^^^^^^^^ TteT:" rlirifr t^ ^^P^'^
at Copenhagen. Denmarrby"wS?ch tCfXT"^ ^ "''^df, as
hire. These coolers made of ^nZ>. *^ ^^ ^ '^^"''^ '«<^ coolers out on
tructible. With ordinary caeZTla^^oft::"' *" ^'^''''^''y '"d-
the tm wears off they can l^e repS ^" *'" or more years, and when
nectioTlurrm"! tuh T'Cf^t 'T P»"P-? -ter. and a con
necessary, ice could ^ L^d fn ?he barrel' "' "'**^'^ P^^*'^'^ ^ «°d
theff^tTatrosfp-s. s^rttr"^!;^ c^ttti tr '-'".-T'
odore. Daciena or Iron, the ahsorption of objectionable
low^'^rSS:"""'^™"' *-""' «""'^ »"<' »'™«ly forbid the fol-
r21 T%1 1"*""-"^ of uncovered cans nnder trees
yard!'* ^'" ''''"■"^ °' »"— ' ™» »- 'tables, piggeries, or ^.
by tlSeSiS:,"""*^ °' ""■" '"■■ ■"<'- "■» "-ort peri«ls on nnlk^,^
30
■I
■ ?
I f
Fiu. 7.— CooLiNci AND Aeratint. Appakatus.
H. Barrel tilled with cold water from well.
Jt. Reservoir to hold contents of milk paila.
C. Cooler and aerator. The milk passes over the corrugatioiiH.
W. Waste water pipe from the cooler. The water enters below on the riaht side am
passes out at W.
«1
the HIIe.l cans "ntiU»rti „:,7 luJu^^^^^^^^^ after ,„ ilk ir.R. and to keep
to collect. ThlH r,K,m neeT not h! I *- " ^''^ ^^'^'.''t*"'' f"r the drawer
convenient to the Htab eTr '1^: . J .Xni''. T.^^'^ive. and it nhould be
placed where there Ih aliab ?rof iX J ^^i '.'" "" *''"''^ "*''""''' '^ »>«
the n.ilk is in d«,,«er f H HorbL"^^ 'f^'" '""•">"'•'» ^"•'t.or where
bu.KI,„;j often Hcrvos the purpose, very weft ^ '''•"'^•' "*'"""''^ »
*<trainer.pails ..tc.ir.r ife Ilk i^^^^^^^ nun.U.r of n.ilk cans. J
should hj .strained an at ono ' ..„ r -T \"""^"J'"t«>V after n.ilkip...
In this way. the co^^^"inf „ 1^^ '• '' "'V'. V'" ^'"''^ "^'"^•^' ^he ccK.ler
after the last pail of „fk was dmw!"" T"', ^"^ "'"■"'""' " f'^^^' """"ten
the interior ol^such a Z.„?hou Id be like'^" ^ '""''^"''"•'"' "'^"^ "^ "''»'
Rkfbrbkckn.
xxxix, 1883, p. 660 ""• *'"''• ^''•"»- "^^ J'»n«.
4. ---«-,^^ a.-j.o„. a. ,.e eon... BuH. S... Che., de ParU. ,„U.
6. />«rJ„,u,_FHbricatio„. maturation, et maladieH du fromage de Cant«l a ,
HKrononi.jues, 1878 'romage ae Cantal. Annalea
10. A r.w;/,/«r.— Molkerei Zeituna 1880 nr •«! „ * j r
11. »'e/<;m«nn, -Milch Zeitung imJ) p 881 ' ^™""''' '"*=• "'*•
12. Co,.n.-Ue..er eine^bitt^e Mnch erzeugenden .ierococeu.. Centra.b. f. B.kt
13. i^«^-.;>..-l.V;r Sh^rilisX^^^^^^^^ "rr -^r "■ '''■
Bicht auf die kindernah'rung B ri Sn W h""' """'^"^ ''""''-
721. *^ "• *^""- "^"'ch. xxvni. 1891, s. 717-
14. Bi«.V/..-ZeiUcrift f. Hyg. xii, p. 81, 18!)3
16. deFren,lenreicf^Ann. de Mic-ographie vii, p. 1. 1806.
lb. O CaiM,,,,.. New 8onth Wales Agr. G«. . Vol. 10. p. 882 1809
fr. den^ .at!::: Cir ii.rntrs^'- ^'^--- ^--
■i
32
19. Piroltit and Xiboiti.— Rendioonti d. K. Inatituo Lombwdo, 1879.
90. f>HWn«4X.— Femtvntatiun iiloooli<|u«M du suore du Isit. Ann. da I'lnat. Past. 1,
1887, p. 573.
21. Adimtts.—BikcclMn>mycw Uotia fine neue milohiuckai- vargahranda. Hafeart.
( antralb. f. Bakt., V. 1880, p. 116.
92. Ihidafue. R«vue critii|ua. Ann. da I'liiat. Past. 18Ht», p. 201.
93. /r<«y«fr. -Leviirea aloouliqutM de Uctoae. Ann. da I'lnat. PMt, V., p. 396, 1891.
94. OroUnfelt.—Wilch /eit., 1891, p. 75».
25. Weiijmann.—Mikh /eitung, 1890, p. 743.
26. Bejerinck. -Aroh. Navrriand, xxiii, 1880, p. 428.
Centrall). f. Bakt., 18H0, p. 44.
27. SehHwmaii»-StttkhovtH.—SMch%tomyon KeBr. Diwi, inau|{., Ttrecht, 1891.
28. d« Frtvdenrekk.—Biktoriol. Untanuoh. Ubor den Kettr. Cuntralb. f. Bakt. abt, II,
iii, 47, 1897.
99. fiucAioecAio.— Contribution h I'etude do la tennentation de la lactoie. Ann.de
Mior, vi., p. 166.
30. •/orneniwn.— Micrf)ur|{aniNmHand fermentation, London, 1900, p. 214.
31. Dudaux. Trait<i de BactKriulogie, Vol. iii, 1900.