DAIRY HUSBANDRY 
25 
EXERCISE NO. 16 
Object: To become acquainted with the Sin-acid test for fat in milk. 
Procedure: The sin-acid (without acid) solution is prepared as follows: 
Mix 7 cc. of amyl alcohol with 31 cc. of 95% ethyl alcohol, and 
add the mixture to 64 cc. of 0.8 normal sodium hydroxide solu¬ 
tion. 
A. Test a lot of milk in duplicate by the Babcock method. 
B. Test the same lot of milk by the sin-acid test as follows: 
Method 1. 
(1) Place 17.6 cc. of milk in a 10% milk test bottle and add 
17.5 cc. of sin-acid solution. 
(2) Mix the sample thoroughly with a rotary motion, and 
finally with a churning motion, with the tip of the bottle 
closed with the finger. 
(3) The bottles should then be placed in hot water (190°-200° 
F.) for 10 minutes and again shaken, and filled with hot 
water (190°-200° F.) up to the neck. The bottles are then 
replaced in the water bath (190°-200° F.) for 30 minutes. 
The fat is then brought into the neck by adding hot water 
(190°-200° F.), placed in a water bath at 140° F. for 5 
minutes and then read. 
C. Sin-acid test—Method (2). 
(1) Perform same as 1 and 2 of B above. 
(2) The bottles are placed in a water bath at 190°-200° F. and 
shaken from time to time until the curd is dissolved. 
(3) Place in centrifuge and whirl for 3 minutes; fill with hot 
water (140° F.) into neck, place in water bath at 140° F. 
for 5 minutes and read. 
Observations: 
San 
lple 
%fat 
Color 
Condition 
1 
a 
2 
a 
b 
3 
a 
• 
b 
