MOTTLED BUTTER 281 



Sammis and Lee repeated a portion of Storch's investiga- 

 tion. They found that butter-fat, freed from casein by melting 

 and nitration, then emulsified with water and churned, -pro- 

 duced typical mottles when the salt was not evenly distributed 

 throughout the mass. They thus produced mottles entirely 

 independent of the casein. Microscopic examination of such 

 butter showed similar results as in the case of Storch's experi- 

 ment. In the portions which were lighter in color, the water 

 was present in the form of innumerable small droplets, while 

 in the portions that were darker, the droplets of water were much 

 larger. No counts nor measurements of the droplets were given. 

 These investigators emphasize the importance of thorough 

 working of the butter to prevent the mottled appearance. 



The mottles caused by improper incorporation of salt assume 

 two different forms, viz., mottles proper, and wavy butter. As 

 has been mentioned before, the mottles result from undissolved 

 salt. Whenever there is undissolved granular salt present, the 

 moisture is attracted and the color deepened at that particular 

 place. In case the water has already been saturated with salt, 

 there is no danger of mottles, no matter how much gritty salt is 

 present. 



Mottles do not affect the quality of butter, but the consuming 

 public desire uniformity in color. For this reason butter is 

 artificially colored during the winter months when cows are 

 on dry feed which is not conducive to the production of a yellow 

 color in the butter. Many people like the appearance of marble 

 cake; the same people would seriously object to marbled butter. 



The salt which is placed on butter or mixed with it has an' 

 affinity for water. Therefore, the droplets of water are attracted 

 to the granules of salt. The result is that a certain portion of 

 the butter assumes a dark appearance, possibly somewhat 

 similar to the clouds appearing before a rainstorm; or, in other 

 words, mottles may be said to be caused by the uneven distribu- 

 tion of the water droplets. 



It will be observed that the white streaks in butter contain 

 little or no salt. Professor O. F. Hunziker has done very 

 extensive work on this subject. The white opaque places in 



