10 



BULLETIN 9'70, U. S, DEPARTMENT OF AGEICULTURE. 



in a dry oven for two hours at 170° C. (338° F.)- In either case the 

 bread should be allowed to cool before it is inoculated with the mold. 

 Freshly baked bread is preferable, for it contains more moisture. 

 When the bread is dry-sterilized it may be improved by putting it 

 into a steam sterilizer for a time in order that the bread may regain 

 some of the moisture lost in the dry-sterilizing process. By means 

 of a sterile platinum needle Roquefort-mold spores from an agar 

 culture are transferred to a flask of sterile water. The mixtiu"e is 

 then shaken and a portion of it drawn off by means of a sterile 

 pipette. The point of the pipette is thrust into the bread in several 

 places and a small quantity of the liquid allowed to run into the 

 ])read in each case. When the pipettes are small several are used 

 for each loaf of bread. It is not advisable to use the pipette twice 



for inoculating the 

 bread. At least an 

 ounce of the water 

 culture should be used 

 for each loaf; too little 

 moisture will result in 

 a meager growth of 

 mold and a great part 

 of the bread will be 

 wasted. The holes 

 made by the pipette 

 may be covered with 

 a gummed label, and 

 it is advisable to cover 

 the inoculated bread 

 with a thin coating of 

 hot paraffin. The in- 

 oculated bread should be put into a moist, cold place (about 60° F.) 

 for several weeks to allow the mold to develop to a stage at which 

 it may be used in the cheese. When grown at a temperature of 

 from 50° to 52° F., it takes two or three weeks for the mold to 

 grow to a stage where it is fit to be made into powder. This condi- 

 tion is indicated by the spreading of the colored mold throughout 

 the bread. 



Foreign molds are more likely to cause trouble at a high tempera- 

 ture, and the desired mold appears to make a more vigorous develop- 

 ment in the cheese when grown at a low temperature. In some 

 instances in which we have grown the mold at a high temperature 

 (room temperature) and held it for a time before using it, the mold 

 has failed to develop properly, or at least luxuriantly, in the 

 cheese. When there is evidence of foreign mold in the bread either 



Fig. 2.— Inoculating the bread with pure culture of Roquefort mold. 



