Document Type


Publication Date



Diary Husbandry Department

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cream, cream separator, milk


Cream quality surveys repeatedly have revealed the farm separator as an important factor affecting the flavor of cream. The relation between the unwashed separator and off-flavored cream has been pointed out and the remedy has appeared to be obvious. The labor required to wash the machine twice daily, however, often has appeared unreasonable when a small value of milk is separated as is the case on many farms. The present work was designed to test the effectiveness of methods which likely would require less labor but might maintain satisfactory cream quality. As early as 1904 the United States Department of Agriculture pointed out that serious cream quality troubles might be encountered unless farmers followed detailed instructions regarding the use and care of cream separators on the farm. Bacterial numberst were reduced greatly when unwashed separators were thoroughly flushed with water, both before and after use, when the bowl was held below 65 degrees F. When it was held at 85 degrees F. profuse fermentation occurred. It has been generally recognized that the separator should be properly washed after being used. This is important because of its influence on (1) cream quality; (2) efficient separation, and (3) the life of the machine. Chlorine solutions have merits when used as germicidal rinses for separators. Other experimenters have used trisodium phosphate or lye, or trisodium phosphate containing 0.25 percent sodium chromate as a corrosion inhibitor. The first two are quite corrosive and trisodium phosphate with chromate solution may be corrosive if solution strengths are not carefully controlled. With these factors in mind, several chemicals were used in these trials, some germicidal, others largely growth retarders. The concentration used was such that effective antiseptic action might be expected without harmful effect on the metal parts of the separator. The number of trials and the concentration of chemicals used in this work were rather limited. Therefore, results are not conclusive.










South Dakota State College of Agriculture and Mechanic Arts, Agricultural Experiment Station