Grade 



Date 



(36) 



EXERCISE 17. 



Object. — To determine the effect of temperature of milk and incomplete 

 mixing of acid and milk. 



Apparatus. — Sample of whole milk; Babcock test outfit. 



Step 1. Measure out two samples, add acid at once and mix thoroughly 

 (usual method). 



Step 2. Measure out two samples, place in water bath at 130° for ten min- 

 utes; then add acid and rotate to dissolve curd. 



Step 3. Measure out two samples, add acid but allow same to stand ten 

 minutes before dissolving curd. 



Step 4. Complete all tests. 



Report. 



Explain below — 



1. The effect of having the sample too hot before adding the acid. 



2. The effects of allowing the sample to stand with the acid on it before 

 mixing. 



3. Give the different colors of fat in the tests above and give reasons 

 for these changes. 



