PROTECTION OF FOOD .45 



it. If we can keep the spores away, no trouble of this 

 sort will arise. For example, jellies made from the juice 

 of fruit, which the housewife puts up for winter use, are 

 excellent material for mold growth, as many a person has 

 discovered after the jeUies have been stored away for a 

 time. There is, however, little difl&culty in preventing the 

 molding. In making the jelly the material is commonly 

 heated sufficiently to kill the spores present, and if it is 

 afterwards properly covered it will keep well enough. 



In protecting jelly from the growth of microorganisms 

 there are several facts to bear in mind. Jelly contains too 

 much sugar and is often too acid to permit the growth of 

 ordinary bacteria. Molds and yeasts, which can grow in 

 it, do not produce spores that are specially resistant to 

 heat ; and these organisms, moreover, cannot grow in the 

 absence of oxygen. Several methods have been proposed 

 for preventing spoilage. One of the most popular in for- 

 mer years was to pour a little pure alcohol or some distilled 

 liquor such as brandy over the top of the hardened jelly 

 to kill mold spores that had lodged there and then to seal 

 with a paper cover. For obvious reasons this method is 

 not in wide use in the United States at present. 



The most common method now employed in the home 

 to seal tumblers of jelly is to pour a Uttle melted paraffin 

 upon the surface of the jelly. The paraffin should be melted 

 in some dish, like a cup, at the lowest temperature at which 

 it will melt, about 140°. The surface of the jelly may then 

 be covered with a thin layer, which will quickly harden. 

 The object of this method of sealing is not so much to 

 exclude mold spores as to keep out air. The molds, un- 

 like many of the bacteria, are unable to grow imless they 



