CAUSE AND PREVENTION OF TAlNTED MILK FROM "ANIMAL ODOUR."

Waikato Times, Volume XVIII, Issue 1550, 10 June 1882, Page 4

CA USE AND PREVENTION OF TAINTED MILK FROM "ANIMAL ODOUR."

To the outsider itf'mUy'B'b'entflike'-awaste of w<gds to occupy time in, talking or writhW Mut'tne stfieli 'of a' thing; ' butf to thSvft&aggF&f "a 1 cheese ' factory > the phrase, •' 'Jointed milk • from animal odours," is, 6f (significance. It reminds us>of<a> fitter enemy, one which, however much we may effect to despise we dare lidti igiforei >' It'refers ud back to. losses incurred. We recognise in it the most active agent 'in the destruction of cheese and butter, and oftener than anything'else'the cause of our goods being " off- 5 flavor," However "trifling j, the odor emanating from milk may seem, it realty. Strikes back to atcau.se. of defect in both butter and cheese, than which none is mqre ipotent. If from, ignorance of its power it has not been appreciated in times past, the introduction of the factory system has revealed its might, and made a terrible display of its destructive energy. We are now , aware that there is something in it that needs looking after. It is now beginning to attract the attention it deserves. Professor Caldwell, of Cornell University, Uuited States, America, suggested that the behaviour of animal odour, "the odour of new milk" was that of a very volatile oil rather than of a gas. To test this suggestion a sample of milk in which odour' nftd ' purposely been allowed to accumulate was distilled, and a small quantity of a clear limped oil with a slightly 1 fellow tinge was obtained. At 35 degress (F) it was as fluid as water, and emitted no odour, but upon' warming a little it quickly assumed an aeriform condition, and disappeared with an intense smell of new milk, the genuine animal odour. A few experiments demonstrating that the odour in question is an extremely volatile oil, the next query was, how does the oil get into" the ' milk? If the odour disappeared upon , cooling and exposing to the air, «'' and never re-appeared, the conclusion would be that it was a secretion of the milk glands, the same as the fatty'niatter in butter. But the formation of the oil does not stop with the discharge of the milk from the udder. It continues to form out of the udder the same as in it, if the milk is kept warm ; as the temperature of the millc^ falls it forms 1 mote and more slowly till it ccasos entirely." "This accounts for our seldom having tainted milk from 1 , I 'animal odour" in our night milk which has stood in the cool -vats' all night exposed to the air. Cover milk closely and keep it warm and the odour will soon become as strong and even stronger than in new milk. Nor is its formation confined' to the udder. The same odor appears to be all the time escaping from the breath and profusely in the jjcrspiration of the cow. The odours in these different cases' vary a little from that in new' milk, as well as from each otheflr, and the odour from milk in different circumstances diffeis in the same 11 way. The milk of a cow smells differently when she is quiet from what it dbes'Svhen she is worried ; differently when she is feverish from what it does whdn slic is not and the odour formed in the' udder is different from that; formed out of the udder, when the milk is closely covered ; yet its general characteristics are so alike as to be unmistakably the same thing. The &ainples of oil obtained by distilling milk under these different circum&tanccs cannot, while liquid, be distinguished from each other, and they all alike fly off in a vapour upon being warmed, but in taking flight each gives off exactly the same odour as the milk it was derived from. The animal odour in the milk of one feverish cow poured into a six hundred gallon vat, full of good milk will spoil the whole of the six hundred gallons, as in other cases of fermentation the yeast oi* ferment, which is the active cause of change and new products, has been found to consist of living organic germs ; so in this case it may fairly be inferred from the close analogy in action and results that the growth and multiplication of organic germs is the cause from which the peculiar odours of milk are derived. Previous to the adoption of cheese factories, the apparently evanescent odour of new milk had attracted but little attention. Its existence had simply been recognised, and so far as dairymen were concerned, little else was thought of it. JBat when it became necessaiy, or at least convenient, to transport milk to factories in covered vessels and to move it while fresh and warm, this odour was soon found to be a disturbing clement. When milk was put into closely covered vessels, which on .account of convenience in handling could not be filled full and carried a mile or more to the factory, the space in the upper part of the vessel not occupied with milk would invariably be filled with a smell of new milk, which seemed to have accumulated till it became so strong as to be offensive. Upon uncovering the can the offensive accumulation of odour was at once dispersed and the dairyman supposed that to be the end of it ; but results in the factory proved differently. Tt soon became evident that the odour had not departed from it, but had actually increased, when received into the factory, and held in large vats, containing several hundred gallons, in a body though exposed to the open air and cooled down to (60) degrees, it still hung to the milk, and its presence affected the cheese, making it porous and spongy, and giving it a strong flavor. The further fact soon became apparent that it varied in intensity with the varying circum- ' stances which affected the cows. The circumstances which contribute to an increase of odour in milk, before it is drawn, are very numerous ; they are in general such as disturb the health or neat the blood of the cow, and these disturbances may consist of mental as well as physical treatment. The following may be specified as among the most /common causes : Oppressive heat of the t. stagnant water. (This is a very linent and efficient cause in producan ' increase of odour) ; scarcity of r — when cows lack a full supply of , ry lor when it is not convenient of 18, j the odor of milk is very soon jcvucu&d — Gorging, as when cows break : intSi forbidden enclosures or are fed with,' more food of any kind than they efih Jiigest. So also with clogging cows, f Jtiving < fast or in any way worrying them.- Too long journeys : A slow pace, /and Jsllort journeys i for cows- in hot ' j weather are required for good milk. Any. 'disease, especially such 'as produces • feverishness : violent usage, paiu, un--easiness, fright, sore teats, garget, cow- . pox,' breathing bad air, as the I odor # from carrion - or the air ' of "fpul'and close stables, or of a filthy cow-shed ; feeding on food in a state of ' decay or highly fermented, as the refuse ' 'of 1 the dairy in a stale' condition, refuse from a. brewery, coarse and sour grasd, gfown.o'n swampy places, or in low moist . ground j rank'green clover in the early ■ stage's of its growth; going to long- with', ottt milking. ' The principal causes which! pjfedfoje- bad odour in milk, before /it is tweii' s from I 'the cow and which after-r. i itSriiß i'becomec the 1 cause of taint, arei, Oppressive heat and stagnant water. Of-. % *ffisfettuises'>which ' increase . . the odour. :in /- milk' after it is drawri, the principal loner I- ig keeping the warm- milk closely cdVered r i6'.Jha# the 1 o'd^ IWchu >was in ■ . Another very^effioient'eausel 1 is defec-

Another : cooling to rapidly, exposing the cans containing the; jnilk jtq (< tbe,hqt sun while m transit, .exposing milk 'to foUjl odors at the dairy ( farm» ; it j 18 no easy task to keep cleai of all these causes, qf inj\iry it must be,doue to have perfect milk., t Ypu have onlj^ ( to ■per that thp cause of the odoriferous oil ,in milk is a ferrfient, ,rfc will* be easily got rid of. Ferments originate frdm'seeds^ 1 distinct as the seeds of "grain, "and ''are like tnem'iin sonic respects, btit more than equal to them in tenacity 'of life ; the ! secfls of ferihent while they remain spbres they retain tyeir vitality under almost any regular changes,' but the inoitient they become developed' into growihg fungi, their destruction like that of sprouted grain is 1 very easy J though they require oxygen in the composition of their food, they ctainot endure it on their surface ; though they Require warmth to develope, a great heat, kills. - TJie, ferments which flourish so luxuriantly in milk can only do so when protected from the attack of oxygen by' a 'liquid cover- ' ing and they perish rapidly when exposed to tne corroding influence of the oxygen in the air, or to a little too much heat. One of the greatest troubles we have to contend with in ,our , cheese making lies in carrying milk warm and closely Confined to our factory. The animal odor is developed in the journey to the factory. If there is the least thing about milk, 1 which is hot'just right, carrying it closely covered,' will soon swell the little defect to a very large one. With proper Ventilation of the carrying cans tainted milk would be of very rare occurrence in our factories, for butter making milk is not improved by transporting, bxxt for cheese making, if properly Ventilated, carrying it to the factory is a positive advantage. Milk, in which a strong taint is liable to develope, appears when first drawn scarcely different from sound milk. It would be difficult to distinguish them, yet when it arrives at the factory the affected milk is so lull of odour as to become offensive. To avoid this increase .of odour on its way to the factory is the most important point, next to avoiding the original cause in the care of the cow. There are also two ways of counteracting this volatile oil. One is to give it a free chance for escaping, it will then pass away without help as it is formed, leaving the milk in its original purity, another way is to cool &o low as to prevent the action of the ferment by which it is formed. This will not only stop its increase, but it will retard the escape 1 of what is already in ' the milk, and if cooled low enough ( will condense it into a liquid, and give it an animal flavor instead of 'an animal odour. Horace Walpole. Hamilton.