10 Dec, 1918.] Bottling of Fruit for Borne Use. 715 



Bacteria are less troublesome in tlie preservation of fruit than of 

 meat or fish, which contain more nitrogenous matter; they are one- 

 celled, and so small that they can be seen only by the aid of a microscope. 

 The reproduction of bacteria is brought about by one of two processes, 

 the geinn either divides into two, making two parts where one existed 

 before, or else they reproduce themselves by means of spores, and within 

 24 hours, under favorable conditions, the progeny of one cell may amount 

 to millions. 



Yeasts and moulds are the more common enemy, usually attacking 

 fruits, while vegetables are chiefly attacked by bacteria, which are 

 harder to kill than yeasts. The latter are also one-celled organisms, 

 that grow less rapidly than the former. They reproduce themselves by 

 a process of budding, and, like bacteria, are invisible to the naked eye, 

 but they are more easily destroyed by heat than bacteria spores. Yeasts 

 are said to be killed at a temperature of 160 deg. F., and, as previously 

 stated, must be destroyed, for should they gain entrance to substances 

 containing sugar and enough moisture they immediately begin to produce 

 alcoholic fermentation, and render the commodity unfit for use. 



Moulds reproduce themselves by spores. They are very small, light 

 bodies, easily carried in the air, and, when settling upon favorable 

 material, speedily germinate. Some impart a mouldy flavour to the 

 material, but do not usually cause fermentation in either canned or 

 bottled fruits. It is to destroy completely all organisms, which in this 

 case are our enemies, that thorough sterilization is necessary, and for 

 this purpose an exposure for a given period to a temperature of 

 212 deg. F. will usually suflice. In some instances a lower temperature, 

 if continued for a longer period, is almost as effective, and is at the 

 same time less likely to injure the flavour and texture of the more 

 delicate kinds. There are, however, in some foods more hardy and 

 resistant bodies, which, being surrounded by a heavy covering, make 

 them more resistive to heat, and they manage to live and retain their 

 vitality for a long time, even when exposed to conditions which kill the 

 parent germ, but with the system of fractional or intermittent steriliza- 

 tion one is able to overcome this difficulty. This extensive or further 

 prolonged heating, of course, would not be necessary, nor suitable, for 

 fruits, most of which require simply a brief heating, but it enables the 

 canning and bottling of the more difficult vegetables, such as peas, beans, 

 <S:c., to be successfully preserved in the home where only kitchen ap- 

 pliances are available, though, of course, where the processing of these 

 vegetables is done under steam pressure the destruction of such active 

 agents is rendered possible within a comparatively short time. 



Sterilizing Vats. 



The principle of sterilizing is the same, whether applied to fruit 

 bottled for home consumption or canned for market. Commercial 

 canning and bottling differs from home methods only in minor details, in 

 which economy of time and labour is of greater consideration. It is 

 also very necessary that all appliances coming into contact with the 

 contents of jar or can should be thoroughly sterilized. 



Many are surprised when they realize how simple an equipment is 

 necessary in order to conserve general or surplus products for an occasion 

 when they are not available in fresh form. Any boiler or cooking 

 utensil, having a well-fitting lid, provided it is deep enough for the 



