History of Natto and Its Relatives (1405-2012 - SoyInfo Center

koji, which also is harmful... The burning of sulphur is useful
in combatting any infection of a koji room.”
Material: “The mold ferment employed in shoyu-koji
manufacture is Aspergillus fl avus Link, occasionally A.
oryzae (Ahlb.) Cohn, or strains intermediate between the
two species.” “Certain Japanese manufacturers add cultures
of pure yeast belonging to the genus Zygosaccharomyces at
the time of placing the fi rst mold-fermented material in the
brine.”
Preparation of ingredients: While soaking the soy
beans, the water should be changed at intervals of several
hours to prevent the formation of spore-forming rods, which
cause heating and souring. The spores of these bacilli are
on the beans as they come from the fi eld. “After being
soaked for 20 to 24 hours the swollen beans are cooked in
an open kettle or under pressure until they are soft enough
to be easily pressed fl at between the thumb and fi nger. This
desired softness can be obtained by autoclaving at 15 pounds
pressure for 50 minutes and also by much longer cooking in
an open kettle. Autoclaving under pressure has the advantage
of sterilizing the material.” After roasting, the wheat is
crushed or cracked. It is important to “reduce some portions
of the kernel to a fi ne powder or dust.” The cooked beans
and cracked wheat are “mixed in large trays or on mixing
tables.” Hot beans “may be cooled with a draft of air directed
over a thinly spread layer.” These “two ingredients need to
be thoroughly mixed, so that the wheat dust may form a coat
over each bean. The lower water content thus induced on
the exterior of the beans makes them better adapted to mold
growth than to bacterial growth.”
“Shoyu-koji–Ripening: After the beans and wheat
are thoroughly mixed, a very small quantity of previously
molded material, such as mature rice koji (tane-koji), some
shoyu-koji, or a pure mold culture, is thoroughly mixed into
the ingredients. The whole mass is then distributed into the
small fl at koji trays (Plate II, inserted between pages 4 and
5) which are immediately placed into the koji fermentation
room before they cool further. Each tray holds about 1.8
liters, or about 2 quarts of raw material. The koji trays are
placed in tiers along the wall of the room (Fig. 3).” They
are usually stacked in a zigzag fashion to ensure adequate
aeration. This is extremely important “because moisture
and the lack of oxygen induce the development of mucors
and bacteria, and are said to cause the diastatic enzyme
to develop at the expense of the proteolytic enzyme. In
some localities in Japan no such trays are used, but a broad
straw mat with which very good koji can be secured.” “The
koji room or compartment is kept at a temperature of 24º
to 25º C., with a defi nite humidity.” Continued. Address:
Microanalyst, Microbiological Lab., Bureau of Chemistry
[USDA].
156. Church, Margaret B. 1923. Soy and related
fermentations (Continued–Document part III). USDA
© Copyright Soyinfo Center 2012
HISTORY OF NATTO AND ITS RELATIVES 96
Department Bulletin No. 1152. 26 p. May 12. [27 ref]
• Summary: Continued (p. 20): Relation of enzymic activity
to soy processes: During the ripening of the moromi, the
essential factors are diastatic and proteolytic enzymes
produced by the mold. But what part do the enzymes of the
bacteria play? “Increasingly great numbers of bacteria in the
koji cause an undesirable fl avor in the fi nal soy sauce.”
Manufacture [of soy sauce] in the United States: Making
soy sauce is a complex, subtle, and diffi cult process. “If this
were not true the process would not be regarded as secret,
as it so generally is in the Orient.” Church was interested
in helping a soy sauce industry to develop in the USA.
“The majority of soy sauce makers and manufacturers in
the Orient employ purely rule-of-thumb methods which
have been handed down and individually perfected by more
or less successful experience. Accurate knowledge of the
reasons for the steps involved in the process as practiced is
not common.”
“Of the almost innumerable ways in which soybeans
are used in the Orient as more or less elaborately prepared
foods, soy sauce seems to offer prospects of more immediate
adoption in the United States than any other product...”
“Soy sauce has already gained a strong foothold with
frequenters of Chinese-American restaurants.
“Table sauces containing soy sauce as an ingredient
are to be had in a great variety of grades and fl avors.
They also present an unlimited fi eld for further variation.
Concentrated forms of seasoning, such as yeast and
vegetable extracts suitable as meat substitutes in fl avoring
soups and other prepared dishes, are receiving consideration
by manufacturers.”
“The manufacturers of table sauces and condiments
interested in soy sauce are among the largest and best known
fi rms of the United States... One company at least in the
United States manufacturers a wholly domestic product.”
Related fermentations (Miso, soy cheese [fermented
tofu], natto). Summary. Bibliography. Address: Microanalyst,
Microbiological Lab., Bureau of Chemistry [USDA].
157. Oshima, Kokichi. 1923. Kôji-kin nado no denpun
tôka kôso oyobi tanpakushitsu bunkai kôso no teiryô-teki
sokutei-hô [A quantitative method for determining the
starch saccharifying enzymes and proteolytic enzymes of
koji mold]. Sapporo Norin Gakkaiho (J. of the Society of
Agriculture and Forestry, Sapporo) 14(63):373-92. May.
[Jap]
Address: Hokkaido Daigaku Suisan Senmon-bu Kagaku
Kyoshitsu, Japan.
158. Hotta, Imakazu. 1923. Kôji-kin no baiyô kyôgû ni
yoru jidai naiteki henka ni tsuite [The inner change of next
generation of koji mold by cultural condition]. Jozogaku
Zasshi (J. of Brewing, Osaka) 1(2):96-99. Sept. [Jap]
Address: Marukin Shoyu K.K., Moto Gishi-cho, Japan.