Sauerkraut 443 



enough, the acid gradually disappears again, and finally 

 the entire mass undergoes decomposition. 



As the juice passes out of the shredded material, the 

 volume of the latter diminishes until it occupies two- 

 thirds of the former space, and, at times, only one-half 

 or even less. In the juice itself, which contains sugar and 

 other carbohydrates, proteins, amides, organic acids, 

 and the like, bacteria and yeasts multiply rapidly. The 

 bacteria that belong to the lactic-acid species, prominent 

 among them being Bacterium lactis acidi {B. Guntheri), 

 change the sugar into lactic 

 acid, while the yeasts change 

 it into alcohol and carbon 

 dioxid. The latter accumu- 

 lates in considerable quantities 

 and leads to the character- 

 istic foam-formation in freshly Fig. 68. Microorganisms of sauer- 

 pickled cabbage. ''™"*- (^ehmer.) 



The bacteria and yeasts apparently present, in this 

 case, another instance of associative action, for both 

 seem to derive a benefit from their partnership. With 

 the increasing amount of bacterial change, the lactic 

 acid accumulates in the juice until it reaches a maximum 

 of about 1 per cent and imparts the familiar sour taste 

 to the material. Under commercial conditions, suffi- 

 cient souring may occur to permit the placing of the 

 sauerkraut on the market within two weeks. In most 

 instances, however, it is not marketed in such a short 

 time. The manufacturer knows that there is but little 

 danger of his goods spoiling under the prevailing con- 

 ditions, namely, the acidity of the juice and the 



