1114 EXPERIMENT STATION RECORD. 



tests sliowoil wide divergences. A correction factor is believed to be better than 

 none at all, but if accurate results are desired it is considered necessary to weigh 

 18 g\n. of cream into the test bottle. The data for the tests are reported. A brief 

 summary of the results was given in a previous publication of the station (E. S. R., 

 15, p. 397). 



How long may a finished Babcock test be preserved unimpaired? J. L. 

 Hii.i.s {Vevtiiunt Stii. Jijit. lUOS, pp. ..'87, :JSS). — Four Babcock tests of fresh nnpre- 

 served milk were made by the author in iSeptemljer, 1900. The bottles with their 

 contents, subjected to wide ranges of temperatures, were kept in the dark for 3 years 

 and examined annually. The readings were not impaired at the end of 1 year nor 

 materially affected at the end of 2 years, but were obscured at the end of the third 

 year. 



"These results are of interest as indicating the possibilities of preserving the 

 actual analyzed material for future use in cases of dispute. It seems likely that a 

 cajiped and sealed test bottle, kept in the dark in a cool place, ought to present 

 readable contents for a year or, indeed, 2 years after the tests were made unless 

 perchance tlie preservative, if sucli were used, should have some ill effect." 



The moisture content of butter and methods of controlling it, G. L. McKay 

 and C. Larsen {loira Sta. Bui. 76, pp. 135-lGG, figs. 5). — The authors discuss overrun 

 in butter making and leaky and dry butter and report experiments conducted for 

 the purpose of determining the influence of different factors upon the moisture con- 

 tent of butter. 



Directions are given for the calculation of overrun. This, it is stated, should always 

 be made from the fat in the milk or cream delivered by the patron, and not from 

 the composition of the butter. American butter is considered low in water content, 

 about 12 per cent being given as the average. As 16 per cent has been quite exten- 

 sively accepted as a maximum standard, it is argued that as a matter of business the 

 producer should come as near as possible to this standard without injuring the 

 commercial quality of the butter. 



Butter may ai^pear leaky or dull and dry, depending upon the way in which the 

 water is incorporated. The chief factors causing the leaky condition are stated to be 

 churning to small granules, washing very little in cold water, salting heavily while 

 the granules are still small and firm, and working very little in the presence of 

 moisture or brine. The dry appearance may be due to an excess of moisture incor- 

 porated by prolonged churning in the buttermilk or wash water, or by churning at 

 a very high temperature. It may also be brought about by overworking, in which 

 case the moisture content as a rule is low. It is stated to be very difficult to differ- 

 entiate between butter containing much and little moisture. When the moisture 

 has been properly incorporated butter may contain much more than 16 per cent 

 without the fact being recognized except by special methods. 



Three experiments were conducted to determine the effect of temperature of cream 

 and wash water on the moisture content of the butter. In each experiment one lot 

 was churned at a temperature of 60 to 64° and one at a temperature of 48 to 54°, all the 

 other conditions being as nearly identical as possible. The average water content of 

 the butter churned at the higher temperatures was 13.83 per cent, and of the butter 

 churned at the lower temperatures 13.24 per cent, indicating no great difference in 

 the moisture content due to temperature alone. 



In 6 experiments the influence of the amount of churning was studied. Samples 

 of butter were taken from the same churning at different stages, and in every 

 instance the moisture content was found to increase with the amount of churning, 

 the greatest increase noted being from 13.25 to 22.99 per cent. It is stated that the 

 samples containing a high moisture content appeared a trifle dull in color and very 

 dry, but did not show the moisture in any way. Churning is considered the most 

 effective means of controlling the moisture content of butter. 



