PRODUCTION OF PINK SAUERKRAUT BY YEASTS 259 



Analysis of sauerkraut 



Chemical: 



1 . Per cent of water in kraut 



2. Total titratrable acid in 100 cc. juice. 



3. Volatile acid as acetic in 100 cc. juice 



4. Non-volatile acid as lactic in 100 cc. 



juice 



5. Alcohol as ethyl 



Bacteriological: 



Number of microorganisms in 1 cc. juice.. 



90.6 

 140.0 cc. O.lN 

 0.247 gram 



1.026 grams 

 0.727 gram 



3,600,000 



88.0 

 147.5 cc. 0.1>f 

 0.255 gram 



1.426 grams 

 0.978 gram 



91,000,000 



Chemical analj^sis failed to show any striking difference in 

 composition between the normal and the pink sauerkraut. Later 

 analyses of other samples indicate that the figures given above are 

 fairly representative of the two kinds of sauerkraut. The 

 results of the bacteriological analyses are of more significance 

 and show that the colored kraut is much richer in microorganisms. 

 By means of direct microscopic mounts from the normal kraut 

 it was found that there was a preponderance of rod-formed 

 bacteria while the pink kraut contained yeast cells almost 

 exclusively. The enormous number of yeast cells in the juice 

 of pink kraut suggested that these organisms might be the cause 

 of the pink pigment. Prompted by the fact that yeasts are 

 usually present in high numbers in pink sauerkraut a great num- 

 ber of dilution plates were poured. Almost without exception 

 the colonies on these plates consisted of yeasts^ but rarely was any 

 pigment developed. 



Many samples of pink sauerkraut were plated and from well 

 isolated colonies transfers were made to glucose yeast-water 

 agar slants. In general these yeasts from pink kraut showed 

 little if any color on agar slants. A few transfers gave a pale 

 pink color. From a large number of cultures three pink colored 

 colonies were selected for further study, numbered 24-1, 85-1, 

 and 95-6. These strains show a difference in color; 24.1 and 



' The term yeasts in this paper is used to designate the true saccharomycetes 

 and also those which do not form ascospores, the lorulae. It is probable from the 

 results of previous workers that these pink yeasts are properly termed torulac. 



