40 DAIRY LABORATORY GUIDE 



EXERCISE 16 



TESTS FOR RENOVATED BUTTER AND MARGARINE 



Object: To determine the action of genuine butter, ren- 

 ovated butter, and margarine, when heated and cooled. 



Apparatus : Samples of genuine butter, renovated butter, 

 margarine; spoon; beaker; and flame. 



Steps: 1. Spoon Test. Take a piece of each sample 

 about the size of a chestnut and melt it in a spoon over a slow 

 flame. Bring the fat to the boiling point and stir gently 

 with a splinter of wood. The genuine butter will produce 

 much foam and make little noise on boiling. The renovated 

 butter and the margarine produce no foam, and boil with 

 much noise and sputtering. 



2. Waterhouse Test. Put about 100 c. c. of sweet 

 milk or water in the beaker and then add a piece of the 

 sample and heat until it is melted. Stir with a splinter of 

 wood while heating and then set the beaker into ice cold water 

 to cool. On being stirred, the margarine will collect in a 

 lump, while genuine butter-fat will remain separated into fine 

 granules. 



3. Mix together well a small amount each of genuine 

 butter and beef tallow, and examine according to the tests. 



4. Mix together well a small amount each of genuine 

 butter and lard and examine according to the tests. 



5. Take equal parts of butter, tallow, lard, and cotton- 

 seed oil; then mix them together well and examine accord- 

 ing to the tests. 



Application: 1. What is the current market value of 

 creamery butter? Of beef tallow? Of lard? Of cottonseed 

 oil? 



2. If butter containing 82.5% of butter-fat sells for 25c 

 per pound, what should be the market price per pound of 



