FERMENTATION OF CARBOHYDRATES 



81 



One of the very few practical uses of the gaseous fermen- 

 tation of carbohydrates is in making ''salt-rising" bread. 

 The "rising" of the material is due not to yeasts but to the 

 formation of gas by certain bacteria which are present on 

 the cornmeal or flour used in the process (Fig. 56). 



Fig. 55.— a "flowing" oil well. 



Another is in the formation of the "holes" or "eyes" so 



characteristic of Swiss and other types of cheese (Fig. 57). 



A great many organic acids are formed during the "acid 



