G4 



REPORT OF THE COMMISSIONER OF AGRICULTURE. 



CHARACTERISTICS OF A GOOD BUTTER. 



Creamery butter is more highly valued than that made in a small 

 way, because the conditions of its manufacture are better understood, 

 the machinery more perfect, and the cream used in better condition. 

 In this way a butter is secured of a pleasant color and agreeable flavor. 



In respect to chemical and physical composition a good butter should 

 present the following characteristics, viz.: 



(1) The percentage of water should not exceed twelve. In most ot 

 the samples examined it was less than this. 



(2) The percentage of salt may vary within large limits. 



In fact, many persons prefer butter perfectly fresh, while others like 

 a large amount of salt. It is doubtful whether the small percentage 

 of salt added ordinarily to butter acts as a preservative. Its only use 

 seems to be one of taste. 



Judging from the table 3 percent, appears to be the amount of salt in 

 American butter, the variations being from a minimum of 1.23 per cent, 

 to a maximum of G.lc. The percentage of salt, therefore, is not to be 

 much regarded in making an estimate of purity. It would probably 

 have to go above 8 per cent, before it could be regarded as an adul- 

 teration. 



CURD. 



(3) How much curd can a good butter have? This is a difficult 

 question. 



If a butter should have no caseine in it at all, it would be a strong 

 presumption in proof of adulteration. If it has too much, its keeping 

 properties are impaired. 



One per cent, of curd cannot be regarded as an excessive quantity. 

 The best butter, however, should contain less than this amount. On 

 account of the great difficulty of estimating the percentage of curd, it 

 would not be safe to make it a criterion of purity. 



SPECIFIC GRAVITY OF THE BUTTER FAT. 



(4) The fat of genuine butter is heavier than that of tallow, lard, or any 

 of the common fats used as adulterants. The specific gravity of butter 

 fat is about 912, water being taken at 1,000. On the other hand, tallow 

 and lard have a relative weight of only 000 or less. This ivS a slight 

 difference, and yet it is a valuable one when the question of adultera- 

 tion is raised. But the difference is so small that only the most careful 

 work in determining the specific gravity with strict attention to tem- 

 perature and manipulation give it any value. Inasmuch as most of 

 the fats which are used as butter surrogates are liquid at 40° C. (101° F.) 

 this temperature of determination has been used in the foregoing 

 analyses. 



The numbers given were not obtained by calculation, but by direct 

 comparison with distilled water at the same temperature. While this 

 method is not absolutely correct, owing to slight differences in the rates 

 of expansion of water and oils, it yet gives the comparative differences, 

 and these are of the greatest importance in such analyses. A butter 

 affording a fat whose specific gravity taken as above falls below 910, 

 would have its genuineness subjected to doubt. 



