22 Ax\NUAL REPOUT OF THE Off. Doc. 



SCHOOL OF DAIRYING. 



(1) riiU'lice in testing milk products. 



(2) Testing of samples to sIioav variations, daily, time of milking, 

 first and last milk, daily, speed, temperature, flushing. 



(8) Butter judging, acid test, fermentations. 



(4) Test (lin-e-day comp. samples from different herds. Cows to be 

 in pairs same time in milk. 



(5) Lecture on cream ripening with cream to be set. 



(6) Churning and packing for market accompanied by explanation. 



EXERCISE L 



Babcock Test: — ^^The quality of milk and cream depends largely 

 on the butter-fat in it. 



To Icjirn the amount of fat, find the weight of milk and the per 

 cent, of fat. 



The Babcock Test merely tells what per cent, of the material is 

 fat. 



The Principle: — The breaking up of the milk, or cream, etc., by 

 sulphuric acid setting the fat free; separating it from the other cou- 

 slitucnts by means of centrifugal force, this being done in a bottle 

 graduated to show the per cent, of fat. 



Vital: — Features are a fair sample, an accurate measure of the 

 amount used, complete separation, and accurate reading of the 

 results, at proper temperature. 



The Milk: — To ba tested, fair sample, thoroughly mixed, pouring 

 if practicable, sample measured with a pipette, 17.6 c. c. See that 

 e;d is r."t b'.o'cen. Milk should I:;' orJiuary room temperature. 



The Acid: — Commercial sulphuric, strength, 1:82 sp. gr. ; amount, 

 17.5 c. c. . ^ 



Strong acid chars the fat — use less of it. 



Weak acid shows Avhite sediment in fat column, use more of it. 



Slant bottle so ingoing acid runs down side of bottle. Mix with 

 the milk at once. 



Whirl five minutes, add hot water up to neck, whirl one mniutc. 

 add water to 8 mark, whirl one minute, read. If using hand tester 

 and room is cool, place bottle in bath at 120 for two or three minutes 

 before reading. 



Read fiom top of upper meniscus to bottom of lower. 



Emi)ty while v.arm, rinse, wash with alkali water, rinse. 



Cream: — To test it the amount required should be weighed into the 

 sample bottle, because the variation in its richness, the amount 

 that will adhere to the pipette and the gas and air mixed in it by 

 hauling or standing, make it imi)0ssible to measure the required 

 amount accurately. The amount, IS grams, or half this amount, 

 in the latter case, with the ordinary cream bottle the reading would 

 have to be doubled. 



The amount of acid used with cream should be reduced a little, 

 and after it is mixed with the cream should be allowed to stand a 

 few minutes. 



Skim ]Milk: — Tested the same as whole milk, except that a little 

 more a'id is i'<'(|uired. The speed of the tester should be increased. 

 A double neck skim milk bottle is required, especially for separator 

 skim milk. 



