330 S AI/TING THE; BUTTER 



per layers of salt in an open receptacle contained as high as 

 32,000 germs per gram, consisting largely of liquefying and non- 

 liquefying micrococci, alkali bacilli, lactic acid bacteria, yeast, 

 Bacterium mycoides, Mucor, Penicillium Actinomyces and other 

 spore forms. These facts obviously show that butter salt ex- 

 posed to the atmosphere may become contaminated with many 

 species of micro-organisms, some of which are of the type 

 dangerous to the flavor and keeping quality of butter. They 

 emphasize the importance of keeping the salt well covered after 

 the barrel is once opened. In a properly managed creamery 

 there should be provided proper covers for the barrels that 

 have been opened and not completely emptied, in order to avoid 

 this unnecessary source of contamination of the butter. 



Some creameries are equipped with a salt chest, or bin, or 

 box, into which they empty and in which they store the salt. 

 These boxes are more conveniently accessible than the barrels. 

 They should be equipped with a well fitting cover and located 

 away from excessive dampness. It is advisable to not fill them 

 with more than one barrel of salt at a time, as the original seal 

 of the unopened barrel furnishes better protection than the 

 creamery salt chest. 



Chemical Purity of Butter Salt. The best buttersalts con- 

 tain from 98 to over 99 per cent pure sodium chloride. The 

 salts of commerce contain besides sodium chloride, small but 

 varying amounts of gypsum, calcium chloride and magnesium 

 chloride. All of these impurities, when present in considerable 

 quantities, are undesirable from the standpoint of the quality of 

 butter. The gypsum reduces the solubility of the salt and the 

 magnesium chloride tends to give butter a distinct bitter flavor. 

 The salts of magnesium also are very strongly hydroscopic, 

 augmenting the tendency of the butter salt in storage when ex- 

 posed to the air, to absorb moisture and to become damp and 

 lumpy. The butter salt should also be free from mechanical 

 impurities such as dust, dirt and other organic matter. 



The chemical purity of the salt is determined largely by 

 the purity of the brine and the process of manufacture used for 

 the elimination of the natural impurities contained in the brine. 

 The purity of the brine varies very considerably with the locali- 



