568 IOWA DEPARTMENT OF AGRICULTURE. 



CREAM TESTING. 



The testing of cream is a subject in which many people now take a 

 lively interest. A great deal.jmore of it is done now than was the case two 

 years ago and I think the universal experience of all those who have car- 

 ried on this work, is that cream testing is far more difficult than milk 

 testing. The ordinary manipulations of the test are generally understood 

 and there are only a few points connected with the subject that I wish to 

 mention. 



THE SAMPLING OF CREAM. 



When cream haulers sample cream at different farms, a box of one- 

 half pint sample bottles should be taken along and this box of samples 

 ought to be iced in summer and kept from freezing in the winter just as 

 carefully as the cream-carrying cans are protected. These half pint bottles 

 filled to the cover will furnish a good sized sample of each lot of cream and 

 when no preservative is used in them the butter maker has a chance to 

 inspect the condition of each lot of cream which was poured into the large 

 cans. This will help him to locate any trouble he may be having with his 

 butter. If these samples get sour and lumpy there is some defect in the 

 method of caring for them during transportation, but I think on the whole, 

 such a large sample as this without using a preservative until it arrives at 

 the creamery, is the most satisfactory one to take and after it has been 

 thoroughly mixed and tested that which is left may be emptied into the 

 cream vat. 



WEIGHING SAMPLE AND CLEARING FAT. 



When it comes to testing the cream I presume that every butter maker 

 knows that it should be weighed and not measlred into the test bottle. 

 The scales made with agate bearings and knife edges are most easily kept 

 in good condition for this purpose than those having metal bearings which 

 will easily tarnish and rust. Another thing that will be of great aid in 

 obtaining accurate readings of the cream fat is to allow the test bottle to 

 cool and the fat in the necks to solidify or crystalize after the last whirl- 

 ing in the centrifuge. This cooling helps to separate the water from the 

 fat which in many cases has not been accomplished by the whirling alone. 

 When re-melted and warmed to about 120 degrees Fahrenheit the fat will 

 be clear, oily, water-free, and in the best condition possible for measuring. 



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THE CREAM TEST BOTTLE. 



A new idea regarding the cream test bottle has been proposed and used 

 somewhat in recent times. This is designed for the purpose of testing very 

 rich cream. The commonly used cream bottles are graduated to measure 

 thirty per cent of fat when eighteen grams of cream are taken, but the new 

 bottle is made with a longer neck and is whirled in a larger tester than 

 those formerly made. My experience with these test bottles is rather lim- 

 ited and I am consequently not able to discuss them, but I have always 

 telt that so long a column of fat as would be separated from a forty to fifty 

 per cent cream, was hard to measure accurately, on account of the careful 

 work needed in regulating the temperature of so much fat. The expansion 

 and contraction of so long a column of fat effects the readings so much that 



