TECHNOLOGY. 



1027 



Analyses pre given of a large number of European and Aniorioan ciders and a short 

 bibliography of French, German and English works on cider making is apjiended. 



The effects of fermentation upon the composition of cider and vineg'ar, 

 C. A. Bkowxe, jr. [Juiu: Am,'r. Chcm. Soc, 25 (190-)'), Xn. 1, pj). lO-.li, fig. 1, 

 dgms. 2).— A 25-gal. cask was filled with the fresh cider of an imknown variety of 

 apples. The cask was stored in a dry, cool cellar from Noveml)er 15, 1898, to October 

 13, 1902, and analyzed from time to time to determine the chemical changes which 

 took place. Fermentation was the greatest from the fourth to the seventh week after 

 storing. During fermentation the sucrose and dextrose were completelv removed, 

 but a small percentage of levulose remained unaffected owing to the develo[)ment of 

 acetic acid, which arrests alcoholic fermentation. In the experiuient 100 j)arts of 

 sugar gave an actual yield of 45.4 parts of alcolml, or a) xnit 88.8 per cent of the 

 theoretical yield. The loss in w'eight of the cider during the 169 days of the alco- 

 holic fermentation was about 2.4 per cent. It is pointed out that in cider making 

 a very serious loss in alcohol may result from the development of acetic aci<l. In 

 the experiment recorded there was a loss of about 0.7 per cent of alcohol foiiuc(l 

 from sugar by the development of 0.23 per cent of acetic acid. The loss in cider mak- 

 ing from this source, it is stated, can be prevented largely by racking off the cider after 

 the main fermentation into other casks and bunging tightly. Since the presence of 

 acetic acid is detrimental to the develo|:ftnent of alcohol, the failures reported by 

 farmers in getting the vinegar to " make" when th(>y add fresh cider to old vinegar 

 is accounted for. 



In the acetic fermentation 100 parts of alcohol gave an actual yield of llf>.;! parts 

 of acetic acid, or 89.2 per cent of the theoretical yield. 



The bung of the vinegar cask was left open for 18 months from Jnl\-, 1900. Dur- 

 ing this period the weight of the vinegar in the cask decreased 30 per cent. 

 The acetic acid content decreased over 2.5 per cent, due mostly to destructive fer- 

 mentation caused by Bncterium xyllimm, or an allied form which had the property 

 of forming cellulose. During the deterioration of the vinegar there occurred a rela- 

 tively high increase in the percentage of reducing sugar. Upon examination this 

 was found to be caused by the presence of 2 well-defined osazones, one of which 

 after recrystallization melted at 142 to 143°, and therefore corresjionded to the 

 phenolformosazone of Fischer. 



"As a remedy against deterioration, vinegars intended for storage should be racked 

 off into clean casks, the latter filled full and tightly bunged. Since none of the acetic 

 organisms can thrive without air, their further development is thus prevented, and 

 the loss from destructive fermentation reduced to a minimum." 



Analysis of the dried settlings in the vinegar cask gave the following results: 

 Moisture, 4.91 per cent; fat, 1.69 per cent; protein, 20.13 per cent; ash, 2.65 per 

 cent; crude fiber, 5.69 per cent; nitrogen-free extract, 64.93 per cent. Analyses 

 were also made of the ash of apples, cider, and vinegar settlings. These are shown 

 in the following table: 



Asli analyses of apples, cider, and vine</ar srtllin</s. 



Potassium oxid 



Ferric oxid and aluminum oxid . 



Calcium oxid 



Jlagnesiinn oxid 



Phosphoric acid 



Stilphuric acid 



Silicic aci<l 



Undetermined carbonic acid, etc 



