EFFECT OF BENZOATE OF SODA AS A PRESERVATIVE. 21 



fication ensued, which was not complete on May 26, the time of the last 

 analysis. 



The juice which contained 0.03 per cent of benzoate of soda fer- 

 mented considerably during the first interval, yielding 4.55 per cent 

 of alcohol, a little acetic acid being formed at the same time. The 

 juice, however, was far from being dry, 3.24 per cent of solids, includ- 

 ing 1.73 per cent of total sugar, calculated as invert, being present. 

 During the next interval there was a slight gain in total acid calcu- 

 lated as acetic, and a slight loss in alcohol. The sugar also diminished, 

 and after one hundred and ninety-two days there were present 2.56 

 per cent of solids, 2.99 per cent of acid calculated as acetic, 2.40 per 

 cent of alcohol, and 1.10 per cent of reducing sugar. The addition 

 of 0.03 per cent of benzoate of soda, therefore, retarded the alcoholic 

 fermentation, but permitted the alcohol formed to acetify. 



Juice preserved by the addition of 0.06 per cent of benzoate of 

 soda showed a greater retardation of fermentation, containing at 

 all times considerably more solid matter, more sugar, and less alcohol. 

 At the time of the last examination, however, it showed not only 

 much less alcohol, but much more acetic acid than any of the other 

 samples, still containing 3.91 per cent of solids, of which 2.02 per 

 cent were sugars. 



The juices containing 0.1 per cent and 0.15 per cent of benzoate 

 of soda, respectively, showed during the first interval of seventy-three 

 days practically no alcoholic fermentation, but increased consider- 

 ably in content of total acid calculated as acetic. After one hundred 

 and twenty-three days the juice to which 0.1 per cent of benzoate of 

 soda had been added contained 11.08 per cent of solids, 1.26 per cent 

 of acid as acetic, 8.52 per cent of sugar, and 0.76 per cent of alcohol. 

 After one hundred and ninety-two days it had lost a large amount 

 of its solid matter, but only small amounts of acetic acid and alcohol 

 were present. 



It was expected that the juice which contained 0.15 per cent of 

 benzoate of soda would show less loss in solids than any of the other 

 juices. This, however, was not the case. The reason for this may 

 be that different organisms developed in the different barrels, and 

 these were affected differently by the presence of the preservative. 



Therefore, while benzoate of soda when added in quantities ot 

 0.03 per cent and over retards alcoholic fermentation, eventually 

 both alcoholic and acetic fermentation do develop, and an attempt to 

 preserve apple juice as a beverage for any length of time by the use 

 of benzoate of soda in quantities tolerated by the regulations would 

 result in failure due to the development of acetic fermentation and 

 consequent depreciation in flavor. 



The alcoholic fermentation which would naturally take place in the 

 absence of both preservatives and sterilization tends to exclude other 



