TESTING CREAM.

New Zealand Mail, 27 August 1902, Page 50 (Supplement)

TESTING CREAM.

Prof. E. H. Farrington writes in the “Farmer’s Review” as follows: —“A letter received to-day inquires :‘‘How much acid should be used in testing cream, and what is. the overrun oil cream that will test from 24 to 40 per cent, fat.” We generally use the normal amount of acid in testing cream, that is, 17.7 c.c. It is a good plan, however, to allow the mixture of cream and acid to stand in the test battle until it turns dark colour, before the bottles are put into the tester. You will notice in testing cream that as soon as the mixture of milk and acid is made, there is no immediate change to dark colour that is noticed in whole milk testing. This is on account of the much arger quantity of fat present- in the cream than in the whole milk. We have found that by letting the mixture stand a few minutes until it turns black, we get a much better separation than in the case when the test bottles are imAnediately put into the tester and whirled while the mixture is light coloured. In case you have trouble in reading the fat cf cream tests, that is, if the .separation is not clear, you will to be a great advantage to let the completed test stand in the bottle a fhw hours, so that the fat will solidify or crystalise. then put the bottle into the machine again or into hot water until the fat is melted. The second separation will be -very distinct. The solidifying or crystalising and then remelting of the fat seems to clear it up verv nicely.

In regard to the overrun or butter obtained from cream, I would suggest that in estimating it. you add about 18 per cent.: that is, for every 100 pounds of cream fat you ought to get about 118 pounds of butter. This is a larger overrun than is obtained from milk, because when it is calculated from the cream fat there is no loss in the skim milk to be accounted for. as is the case when the overrun is calculated from the whole milk, the only lo.ss from the cream fat being what is left in the buttermilk. If you have 500 pounds of cream testing 30 per cent, fat, this contains 1-50 ponrius of butter fat. Now. the amount of butter that this 150 pounds of fat will probably make, may be found by multiplying it by 1.18. which gives 177 pounds of butter. The overrun will vary somewhat wiri> cream, in the same way that it does when calculated from Hie milk, depending on how much water is left in the butter, but as an average figure I think you will find that 18 per cent, is a very reasonable one to use when calculating the overrun from cream.