16 
BULLETIN 1152, U. S. DEPARTMENT OF AGRICULTURE. 
thought that it resembled the heavy soy made by Japanese house- 
wives in the country districts. 
Agreement as to exact requirements for the best shoyu seems not 
to have been reached, even among Japanese themselves. The highest 
quality of shoyu in Japan is said to go under the label " Mogi " or 
" Kikkbman," but chemical analyses in Konig (11) and in the Bureau 
of Chemistry records indicate no consistent chemical composition. 
Bacteriological Examination. 
The well-known role of many varieties of microorganisms, for 
example in the dairy industry, makes it impossible to disregard the 
activity of bacteria and yeasts in the ripening of the salt shoyu mash 
or moromi. The established importance of the mold Aspergillus 
flavus and its enzymes to the process is, however, recognized. The 
microorganisms present in the mash in a living condition may exert 
a positive influence. A direct examination of the mash shows a 
variety of bacterial forms. Stained slides indicate that certain of 
these bacteria are living actively, while the majority are in spore 
form. Plate counts may be used to demonstrate how many viable 
bacteria of certain types are in the mash. Total plate counts made 
on the ingredients of the sauce, on the immature and mature koji, 
and on the mash at intervals during the course of this ripening also 
determine at what points in the making of particular lots of sauce 
the bacterial increase occurs and its rate of increase. The bacterial 
forms developing in moromi made in the Bureau of Chemistry seemed 
to be predominately of one group, Bacillus mesentericus. Other 
recognizable groups of bacteria and yeasts appeared only inter- 
mittently. 
In January, 1920, two lots of sauce were started. One was com- 
posed of soy beans and wheat and the second of peanut press cake 
and, for the most part, wheat as a starchy substance. These may be 
designated as moromi 1 and moromi 2. Fresh koji and brine were 
added to these mashes for more than three months. With the assist- 
ance of Dr. Edwin LeFevre, of the Bureau of Chemistry, a series of 
smears and later dilution cultures were made of these two mashes. 
Smears were made as a means of preliminary investigation. Appa- 
ratus was devised by means of which samples could be secured at any 
one depth without contamination from other depths. The results 
of this examination are given in Tables 1 and 2. 
Table 1. — Results of examination of smears made from moromi. 1 
Date 
Moromi 1 (Jan. 15-Feb. 18). 
Moromi 2 (late Jan.- Feb. 18). 
amined. 
Surface. 
Below surface. 
Center. 
Surface. 
Below surface. 
Center. 
Feb. 13 
A few spore 
bearers: mi- 
crococci. 
Spore bearers 
present. 
Numerous spore 
bearers; 
yeasts. 
Feb. 18 
Very few spore 
bearers. 
quite numer- bearers, 
ous; yeasts. 
bearers; 
yeasts. 
1 Gradation of terms used: Very few, few, present, numerous, quite numerous, very numerous. 
