SOY AND RELATED FERMENTATIONS. 2'6 
The manufacturers of table sauces and condiments interested in 
soy sauce are among the largest and best known firms of the United 
States. Their evident desire for information in regard to the work 
of the department on soy sauce has led in part to the preparation 
of this bulletin. The experimental work of a purely laboratory 
nature included in this bulletin is indicative of the stage which the 
soy sauce industry has reached and suggestive of what problems 
the prospective soy-sauce manufacturer in a new country must con- 
tend with, if he is to carry on the fermentation process in anything 
but a blind or haphazard way. Several manufacturers at present 
have soy sauce experiments under way in their laboratories. One 
company at least in the United States manufactures a wholly domes- 
tic product. 
RELATED FERMENTATIONS. 
Soy sauce is only one of the mold-fermented food products origi- 
nating in the Orient, the majority of which are ripened by means of 
the molds represented by the yellow-green group of Aspergilli. 
Miso. one of these products, is one of the most common breakfast 
foods for children. There are two types of miso. white or shiro miso 
and red miso. Miso is prepared from a koji ripened by means of 
the A. flavus oryzae group of molds. The soy beans are cooked in 
miso before the fermentation is undertaken. The treatment subse- 
quent to the cooking and preparatory to the fermentation doubtless 
varies in different localities. It is said that the beans may be made 
into a paste before being ripened by the mold. As bought in this 
country, however, miso shows the beans intact. White miso is said 
to be made from a koji of soy beans or soy beans and a starchy ma- 
terial, as rice or barley. The koji is ripened as is shoyu-koji and 
placed in a weak brine for 10 days. Unfinished rice wine may be 
added to improve the flavor and to preserve the product, which is 
rather perishable. Eed miso is prepared in the same way as the 
white miso. but is ripened for from one to three months in a stronger 
brine. White miso has been bought in the United States in two 
forms. One type is very salty and therefore less perishable than 
the other. Probably because of longer fermentation red miso is dark 
red. It is very cheap, whereas white miso is expensive. 
In China the curd, or to-fu, made from soy-bean milk, is ripened 
with a mol<J preparatory to a ripening in brine. Such products are 
commonly termed cheese by travelers. The to-fu is cut into square, 
rather thick. pieces which are arranged on the narrow face in rows 
upon traylike racks. The racks -are stacked zig-zag fashion, or so 
that aeration is possible under damp conditions. The squares of bean 
curd become overgrown with a mold. The final cheese as received 
in the United States shows the mold on the squares of curd as white 
mycelium with no fruit. After the development of the mold on the 
curd the squares of to-fu are placed in brine for further ripening. 
At the completion of this ripening the product is utilized as a food 
product. It comes into this country commonly as canned white or 
red squares of fairly salty bean ctird. covered with a salty liquid 
which is thick because of the crumbling from the curd itself. The 
red color in such mold-ripened and brined to-fu is due to red rice, 
made by changes produced upon rice kernels by the mold Monascus 
purpureas Went. 
