SOY AND RELATED FERMENTATIONS. ^1 
The question of the influence of microorganisms and their enzymes 
on such a complex product as the mash of soy sauce is hard to solve, 
even with the aid of experimental evidence. The question can, for 
the most part, at present be answered only indirectly. It may seem 
that a consideration of enzymic activity can have little practical re- 
lation to the process of shoyu manufacture. The whole process of 
shoyu-koji fermentation, however, emphasizes the building up of the 
mold enzyme, protease. Other organisms are able to form protease 
in such a manner as to break down proteins more rapidly during 
their active growth than the yellow-green Aspergilli, but the flavor 
produced by bacterial proteolysis is not that of soy sauce. While 
water-soluble protein is formed by the activity of the mold fer- 
ments used for shoyu, as well as by certain accompanying bacteria, 
investigation has proved that the delicate manipulation essential for 
a clean koji fermentation causes a satisfactory accumulation of 
enzymes in the mature koji. The activity of the mold enzymes in 
the moromi or brined mash depends intimately upon how the salt 
content of the mash is built up. 
The vegetative portions of the mold growth and the billions of 
spores produced in the shoyu-koji are present throughout the moromi 
because the moromi is stirred daily. Do the intra-cellular enzymes 
( L 15) of the mold eventually come out into the mash from a goodly 
proportion of the mold material and thus aid in the gradual breaking 
down of the higher proteins into simpler protein as is desired in pro- 
ducing a well-flavored shoyu? Kopeloff (12) has indicated that in- 
tra-cellular enzymes of mold spores (Aspergillus Sydowii) are the 
cause of deterioration in sugar. The selection of the strains of the 
shoyu mold ferment best adapted for shoyu-koji may be based on 
tests of enzymic strength of the particular mold strains. In fact, K. 
Oshima ( 15) . working in the Bureau of Chemistry, has demonstrated 
that of the strains of the Aspergillus oryzae-fiavus group only those 
actually related to the shoyu industry have marked proteolytic 
strength. 
MANUFACTURE IX THE UNITED STATES. 
The variations in the flavor of oriental soy sauce should reduce 
the task of American manufacturers of this product. The American 
product would not be compelled to compete with a product having 
only one recognized standard of flavor. If the sauce the manufac- 
turer developed had an individual flavor of its own. there would be 
less prejudice to break down when he placed it on the market. All 
of which, however, should not lead to satisfaction with an output 
lacking uniformity nor to the acceptance of flavors produced bv 
hurried or improper processes of ripening. It has been shown that 
unsatisfactory flavors in soy sauce can readilv be correlated with a 
predominance of bacteriarinstead of mold activity. A low brine 
content in the moromi while fermentation is in progress, as well as 
too high a temperature during this period, produces conditions favor- 
ing these undesirable flavors. 
There are many difficulties in conducting a process like the manu- 
facture of soy sauce. If this were not true the process would not be 
regarded as secret, as it so generally is in the Orient. In Japan the 
process of shoyu manufacture is conducted in relatively modern 
