MOLD ON BUTTER 307 



favors mold growth. Well-washed butter is less subject to 

 mold. Leaky butter butter from which water or buttermilk 

 exudes and collects in the wrappings or the container fur- 

 nishes the best conditions for the beginning of mold growth. 

 From these wet areas colonies may spread to the butter itself." 

 These facts point to the necessity of churning at the right tem- 

 perature, washing the butter properly with water at the right 

 temperature and properly working it, so as to free the butter of 

 excess of curdy matter and buttermilk and make a butter that 

 is not porous but close, and in which the moisture is incorporated 

 in fine particles instead of larger droplets. They also show the 

 importance of packing butter closely so as to free it of air pockets 

 and fissures. 



Conditions Favorable to the Growth of Molds. Like all 

 other plants, large and small, molds require certain conditions 

 for growth. They differ from ordinary plants in that they do 

 not require light for their growth, but grow rather better in the 

 absence of light. They require suitable food, but find this in or 

 on almost any organic matter, animal or vegetable, such as 

 bread, meat, leather, cheese, etc. They require moisture, and 

 hence develop rapidly in damp rooms and on damp surfaces. 

 They require a certain amount of air and will not grow in the 

 absence of it. As to temperature, while they develop most 

 rapidly in a reasonably warm atmosphere, many of them can 

 accommodate themselves to a wide range of temperature. 



Discolorations. The colors produced by molds range from 

 such light colors as orange-yellow to such dark colors as green, a 

 smudged or smoke color and black, according to the type of mold 

 present. 



Propagation of Molds. Molds reproduce themselves by 

 means of buds (conidia) and spores, and these float so freely 

 in the air that practically no exposed surface is entirely free of 

 them, and all they need for development is the suitable condi- 

 tions we have already outlined. 



Sources of Mold on Butter. The two most common sources 

 of mold on butter are the tubs or boxes in which it is packed 

 and the parchment paper. Wood that is green, sappy or damp 



