12 DAIRY LABORATORY GUIDE 



EXERCISE 3 



EFFECTS OF ADDING CHEMICALS TO DAIRY PRODUCTS 



Object: To determine the physical effects of adding 

 chemicals to milk, cream, skimmilk, and pasteurized milk. 



Apparatus: Samples to be examined and a microscope. 



Steps: 1. Place a drop of milk upon a slide and then 

 add a drop of dilute acid. 



2. Place a drop of milk upon a second slide and add a 

 drop of dilute rennet extract. 



3. Place a drop of milk upon a third slide and add a drop 

 of ether. 



4. Prepare samples of cream, skimmilk, and whey in the 

 same manner. 



5. Diagram the field each time before and after applying 

 the chemical agent. 



Data: 



Application: 1. What particular constituents of milk 

 are affected by the acid? By the rennet? By the ether? 



2. In what way is pasteurized milk affected by these 

 agents? 



