OFFICIAL INSPECTIONS JO. Jl 



ACETIC FERMENTATION 



Certain forms of bacteria act upon the alcohol of cider and' 

 convert it into acetic acid, the presence of which in sufficient 

 quantity is the abject of the maker of vinegar. The conditions 

 most necessary for the acetic fermentation of cider are acetic 

 bacteria, an abundant supply of air, and a temperature between 

 65 degrees F. and 85 degrees F. Theoretically, 100 parts of alco- 

 hol yield about 130 parts of acetic acid, but the actual yield is 

 unusually below 120. 



At cellar temperatures, the acetic fermentation takes place 

 slowly, requiring about 18 months. The addition of vinegar 

 containing "mother" to cider after the completion of the alco- 

 holic fermentation increases the rapidity of the formation of 

 acetic acid. 



DECOMPOSITION OF VINEGAR 



"Several different organisms have the power of decomposing 

 dilute acetic acid and thus destroying the value of vinegar. 

 These organisms work only in the presence of air. Accord- 

 ingly, this destructive change in vinegar can be prevented by 

 excluding air, when once the acetic acid has been formed^ In 

 practice, this can be accomplished by drawing off the clear 

 vinegar, placing it in a clean barrel, filling it as full as possible 

 and putting the bung in tight." 



Legal standards for cider vinegar are usually based upon the 

 percentage of acetic acid and cider vinegar solids. Where 

 proper fruit is used for cider-making, and where the conditions 

 of fermentation are properly controlled, there should be no 

 difficulty in making cider vinegar that contains above 4 per cent 

 of acetic acid in 18 to 24 months. 



PRODUCTION OF VINEGAR BELOW STANDARD 



Several different conditions may cause the production of 

 cider vinegar low in acetic acid, among the more common of 

 which are : Poor apple juice. Conditions unfavorable to the 

 necessary fermentation processes. Lack of proper care after 

 acid is formed. 



