CHARACTER AND COMPOSITION OF CREAM.

Te Aroha News, Volume VI, Issue 279, 7 July 1888, Page 6

CHARACTER AND COMPOSITION OF CREAM.

Cream is the fatty portion of the milk which rises to the top when the milk stands ut rest. The difference in the spec fie gravit y of cream and milk necessarily causes this separation ; indeed to some extent this separation is partially made in the reservoirs of the udder, for it is a well-established fact, that the first drawn mtlk is less rich in cream, or fat, than that drawn at the end of the milking. The cream rises more rapidly under certain circumstances, as when the milk is set in deep pails, in cold water, at a temperature of forty-five degrees, when all the cream is raised through eighteen or twenty inches of milk in twelve hours ; while at sixty degrees it will require thirty hour* to rise completely through three inches of milk set in shallow pans. Also when the milk is diluted with water, the cream rises more quickly, because the milk becomes leas adherent. The low temperature of forty-five degrees reduces the milk to almost its maximum den-ity, which is at thirty-nine degrees ; hence the cream is comparatively lighter than a higher temperature. This fact is taken advantage of in the use of the deep pails and low temperature for setting milk for cr°am ; an innovation which has been of the greatest value in butter making. The cream raised in this manner is, however, more fluid, and has more milk mixed with it than that raised in shallow pans ; but thh is also an advantage, because it is then in the best condition in respect of fluidity for the churn. Cream is simply the butter globules of the milk gathered together into coherent masses with a small quantity of the milk held by molecular attraction among and between the fat globules. Milk consists really of a colourless liquid, in which are suspended an enormous number of minute globules. As milk is a serous viscous fluid, and adherent and adhesive, when air is forced into it it foams and produces a cohesive froth, consisting of Finall and large air bubbles. This is precisely the character of beer, or a solution of soap, gum, syrup, or any other mucilaginous or saccharine fluid. If a quantity of any one of these fluids is warmed to the temperature of new milk, or one hundred degrees, and a small quantity of butter oil is added and thoioughly mixed with it, and the mixture is agitated, the oil soon separates into small glouules, which, when viewed under a microscope, appear in every respect precisely bimiku to the butter globules in milk. ThL? mixture is known as an emulsion, and &imi ar mixtures are commonly used in medicine for the purpose of administering oils in a convenient and desirable form. When auch an emulsion it permitted to remain at rest, the globules rise to the surface slowly and form a cream. When these emulsions aie churned at a temperature at which the fat is boft and non-adherent, the globules are beaten tiuar and finer as with cream in the churn, under those condition* in -*hioh the butter "will not come." When churned at the ordinary temperature of thedaiiy, the fao globules are gradually gathered into granules, and then small masses or grains, and finally form butter. The number of these globules contained in milk of average richness in butter is enormous, and they difier in this re»pecfc considerably with various cow? ; and as much in the size of the globules. Moreover they differ in the same cow »s regards* size and number, when any disturbing influence occurs to affect the nervous condition of the cow, or to excite or to tranquillise her. Thus in a cubic millimetre, or about the one hundredth part of a quail, there are nearly three millions of these globules ; thus giving about three hundred millions of them in a quart of milk, or rire millions i i every cubic inch. Cream varies very much in character, and this variation has a most important bearing upon the business of a creamery, in which, necessarily, there are many kinds uf cream gathered trom the large number of patrons The following analyses of cream gathered by Professor Wauklyn trom different cows, show a most remarkable and important variation.

The result of such a difference as this, and ib is by no means an uncommon occurrence, is of the highest interest to dairymen selling cream to the creameries by the inch or gauge. L For if one inch of No. 2 gives a pound of butter, an inch of No. 4 would' give two pounds live ounces, «nd an inch of No. 6 would give over three pounds. If No. 6 gives a pound of butter per inch, No. 2 would give leps than six ounces. Either the patron, .would lose or gain as his cream might be richer or poor«r, and 1 the creamery would, do the same, as the cream might be, poorer , or u richer, In any case there,' would ,be great loss anc^ injustice to 'some,, persons concerned. — American. AyricidturisL ' ,

I'KK UKNT. OK WATKR. SampteNo. 1 72.20 „ 2. . . 71.20 „ 3 66.36 „ 4 ' 60.17 „ 5 ..*. .1 53.62 „ 6.. .... 50.00 • DUG AR, | Ash, and! Fat. Caskinic. 8.80 19.0 14.70 14.1 14.77 18.87 6 81 33.02 8.21 38.17 5.63 43.91