370 EXPEEIMENT STATION RECORD. 



reaches a high point, 0.3 to 0.4 per cent for instance, and the separator is used 

 continuously for an hour or more, it will eventually clog the same as in the 

 ease of cold milk. The cream will then become thicker until the separator is 

 entirely clogged. The extent of the clogging will depend on the amount of 

 acid in the milk and the size of the machine. The higher the acidity and the 

 smaller the niaehine the sooner the separator will clog." 



Improving the quality of cream from inferior m.ilk, W. D. Saunders 

 {Virginia *S7«. Bill. 162, pp. I40-I0O, fius. 2). — In the method described in this 

 bulletin sour or bad-flavored milk is closely skimmed and the cream so obtained 

 is diluted to any desired extent with fresh skim milk. 



In one of the experiments reported a composite sample taken from 12 lots of 

 milk and cream showed an acidity of 0.24 per cent. The cream, as taken from 

 the separator, showed an acid content of 0.117 per cent. The skim milk used 

 for diluting the cream contained 0.15 per cent acid. The acidity of the mixture 

 before pasteurizing was 0.13 per cent and after pasteurizing 0.121 per cent. A 

 can of this cream which contained 40 per cent of fat w-as cooled to a low tem- 

 perature, covered with a felt jacket about 1 in. thick, and shipped to New 

 Orleans, the time in transit being about 36 hours. So far as known this cream 

 reached its destination in prime condition and gave good satisfaction. 



Two other experiments of a like nature are reported. 



Effect of bacteria in wash water of butter (Kansas Sta. Bui. 138, pp. 

 212-222, fiys. 2). — Experiments were conducted at the station at three different 

 times of the year to determine the amount of contamination in various kinds 

 of water used for creamery purposes. Determinations of the number of bac- 

 teria in well water, pasteurized, sterilized, filtered, and treated in other ways 

 and in melted ice are reported, and scores are given of the butter washed with 

 the different kinds of water. The conclusions drawn from the work are as 

 follows : 



" 1. It is both practical and economical to sterilize wash water for butter if 

 it can be cooled and used immediately. Otherwise, the practice is a useless 

 expense. 



" 2. A filter for creamery water is only a source of contamination and filth 

 unless frequently cleaned and refilled with fresh filtering material. 



" 3. Water melted from ice, even though kept at 50° F., may become filled 

 with bacterial growth if allowed to stand for a few hours in a wooden tank 

 from day to day without thorough cleaning. Great care should therefoi-e be 

 taken in the utilization of such water for cooling purposes. 



" 4. There is a direct relation between the bacterial content of the wash water 

 used and the keeping quality of the butter. 



" 5. Water kept at a low temperature from 40° to 50° F. for a few hours 

 inhibits the development of bacteria, or destroys from one-half to four-fifths of 

 those present." 



Investigations in the manufacture and storage of butter. II, Prevent- 

 ing molds in butter tubs, L. A. Roueks (U. .S'. Dcpt. Ayr., Bur. Anitn. Indus. 

 Bui. 89, pp. 13, fig. 1). — Notes are given on molds and experiments on prevent- 

 ing their growth in butter tubs are reported. 



In each of G trials, 1 tub was soaked in cold water over night in the usual 

 way, 1 was boiled 5 minutes in a saturated brine and left in the brine all 

 night, 1 was soaked over night in a brine containing 9 per cent of commercial 

 formalin, 1 was coated on the inside with paraffin, and 1 was immersed for a 

 few seconds in a bath of paraffin at 2.50° to 2G0° F. All the tubs in each lot 

 were filled from the same churnin : and otherwise treated alike. 



Of the untreated tubs all became moldy. Of those treated with hot brine, 1 



