KEPHIR 165 



amount of alcohol in koumiss is as little as 1-7 per cent and there 

 is not as much as i per cent, of lactic acid. 



Kephir, the second example named, is an effervescent alcoholic/ 

 sour milk prepared by inhabitants of the Caucasus from the milk 

 of goats, sheep, and cows. The process of fermentation is a 

 double one, and precisely parallel to that occurring in the pro- 

 duction of koumiss. Its method of manufacture is simply to 

 add to milk a few " kephir grains," allow the milk to stand 

 for twenty-four hours at a temperature of 17° to 19^ C, pour off 

 the milk and mix with fresh volumes, and so on. Fermenta- 

 tion is complete in two or three days* time, and the resultant 

 fluid contains about 2 per cent, of alcohol, being slightly more 

 than in koumiss. 



The kephir grains are whitish or yellowish irregular granules 

 about the size of a walnut, and of tough gelatinous consistence. 

 They have been carefully studied by Beyerinck,' Mix,- Rothschild,^ 

 and other workers and appear to contain several organisms and 

 yeasts, the former bringing about lactic and the latter alcoholic 

 fermentation. Kern isolated a bacillus which was named Bacterium 

 dispora caucasia and Beyerinck states that this organism causes 

 lactic fermentation. Two forms of streptococcus, a and y8, have 

 also been found. Lastly, a kephir yeast and a true saccharomyces 

 (Jorgensen) have been isolated from the grains. The latter was 

 capable of fermenting milk by itself But there can be little doubt 

 that the kephir fermentation is a double one changing lactose into 

 lactic acid, and subsequently to dextrose, and the dextrose into 

 carbonic acid and alcohol. Exactly what role each individual 

 fermenting agent plays it is impossible to say at present, but in all 

 probability the bacteria perform the lactic, and the saccharomyces 

 the alcoholic, fermentation.* 



1 Arch. Neerl., 1888-89, P- 428. 



- Proc. Am. Acad. Arts and Sc, 26 (1891), p. 102. 



3 L Allaitement, Paris, 1898. 



* A closely allied example of an alcoholic fermentation occurring alongside 

 other chemical changes is obtained in the ginger beer plant investigated by 

 Professor Marshall Ward in 1891 (see Philos. Trans. Roy. Soc, 1892, vol. 183, 

 pp. 125-197). It does not, however, set up alcoholic fermentation in milk-sugar. 

 Its activity depends on Sacch. Pyriformis and Bacillus venniformis. Another 

 example of symbiotic fermentation is the fermentation of the sugar cane in 

 Madagascar, and consisting again of a yeast and a bacterium associated. To 

 these, as well as the alcoholic fermentations in milk, may be added Wino- 

 gradsky's clostridiutn^ and nodule bacteria in Leguminosas. 



