RECORD SHEET. 11 



which, judged only by analytical data, reveal only slight individual 

 differences. On the other hand, there are some well-tested yeasts 

 which show a considerable difference in the amount of alcohol pro- 

 duced from the fruit juice. Also, in certain cases, the finished prod 

 ucts from the same must, fermented by different yeasts, ha- been 

 pronounced quite dissimilar when judged by experts. These dis- 

 similarities in the products derived from the same fruit juice, when 

 fermented by different pure yeasts under like conditions, must result 

 from peculiar vital qualities of the particular yeast organism which 

 dominates the fermentation. The chemical composition and pecul- 

 iar qualities developed in cider by the use of some of the pure races 

 of yeasts selected and tested by the writer have been described in a 

 previous report. No attempt is there made to explain or discuss the 

 peculiar qualities, seemingly inherent in the yeasts, upon which the 

 results obtained seem to depend. The data are as yet insufficient to 

 warrant a critical discussion of these phenomena, yet the results 

 thus far obtained are so illustrative of the chemical activities of 

 these organisms that some examples are presented as a contribution 

 to the study of the yeast ferments. 



The work reported in the study of the composition of ciders as de- 

 termined by dominant fermentation with pure yeasts (Bulletin 88) 

 was carried on in 50-gallon casks, thus approaching commercial con- 

 d it ions. Such experiments, unfortunately, do not afford sufficient 

 opportunity for the intimate study of the individual peculiarities of 

 the yeast, and the yeasts used in the practical experiments reported 

 in the bulletin mentioned were first subjected to the laboratory test in 

 fermentation flasks. 



Later and more detailed fermentation tests in the laboratory have 

 included a considerable number of yeasts and some associated fungi 

 common to fruit musts. Only such of the tests are here reported as 

 show possibilities for future development and indicate the direction 

 for further studies. 



RECORD SHEET. 



The record sheet devised for use in the study of the chemical ac- 

 tivity of yeasts in this laboratory contains the following data, which 

 are arranged in tabular form on one sheet for filing : 



Date, October 24, 1902. TEST NO. 68. Yeast No. 8. 



Sowed at 2 p. m., 400 cc. Must, Apple. No. 4. Vessel, Erlenmeyer, with 

 organism from Tube No. 8. Sown (date) Oct. 24, 1902. 



a U. S. Dept. of Agr., Bureau of Chemistry, Bui. 88, the Chemical Composi- 

 tion of Apples and Cider. 



