Am'Alf,\marm'}    Recent  Literature  on  the  Soja  Bean.  311 
its  indigestibility,  and,  when  dry,  slow  yielding  to  the  cooking  pro- 
cess. In  order  to  overcome  these  difficulties,  there  have  been  pre- 
pared in  Japan  since  the  remote  times  when  the  soja  bean  was  first 
used,  at  least  three  products,  miso,  natto  and  tofu,  in  the  manufac- 
ture of  which  the  aim  is  to  produce  an  easily  digestible  and  nutri- 
tious food. 
The  first  of  these,  miso,  as  described  by  Kellner  {Bulletin  of  the 
Imperial  College  of  Agriculture,  Vol.  I,  No.  6,  and  Chem.  Zeit.}  19, 
97,  120  and  265),  is  made  on  a  large  scale  in  special  factories  and 
on  a  small  scale  in  private  families.  The  first  step  in  this  prepa- 
ration is  the  manufacture  of  koji,  a  diastatic  ferment,  from  rice  or 
barley.  The  rice  is  steamed  until  the  form  of  the  grain  is  not  quite 
destroyed  or  the  starch  cells  fully  burst.  It  is  then  spread  on 
straw  mats  and  allowed  to  cool  to  280  C.  Spores  of  the  mould 
Aspergillus  oryzae  are  then  mixed  with  the  rice  and  the  mass  placed 
in  a  room  at  200  C.  for  twenty-four  hours,  during  which  time  the 
temperature  rises  to  400  C.  It  is  then  divided  into  small  portions 
and  placed  in  a  warm  part  of  the  cellar  for  twelve  to  twenty-four 
hours,  when  it  is  well  kneaded  and  allowed  to  cool ;  the  latter  is 
hastened  by  the  addition  of  cold  water,  if  necessary.  In  about  three 
days  from  the  steaming  of  the  grain,  the  process  is  completed  and 
the  rice  is  permeated  with  a  fine  mycelium;  the  product  is  koji. 
The  miso  is  then  made  by  taking  5  parts  of  soja  beans,  3  to  6 
parts  of  rice  or  barley  koji,  1^  to  2  parts  salt  and  1  part  water. 
The  beans  are  steamed  and  broken  up,  mixed  with  salt  and  water 
and  the  koji  added  to  the  cooled  mixture.  The  procedure  then 
depends  somewhat  upon  whether  the  miso  is  needed  soon  or  not. 
The  temperature  regulates  the  rapidity  of  the  process,  and  if  there 
is  no  particular  haste  required,  it  is  maintained  as  low  as  possible. 
The  finished  product  is  a  stiff,  brownish-red  porridge,  of  a  variable 
composition,  containing  as  much  as  50  per  cent,  of  water,  1  per 
cent,  of  alcohol  and  some  free  acid.  There  are  at  least  four  varie- 
ties of  miso,  varying  in  the  time  required  in  their  manufacture  from 
three  or  four  days  to  one  and  one-half  years. 
Natto  is  prepared  by  boiling  the  beans  in  water  for  four  or  five 
hours,  until  they  are  perfectly  soft.  The  mass,  while  still  hot,  is 
wrapped  in  straw,  and  the  bundles  thus  formed,  when  well  tied  at 
both  ends,  are  placed  in  a  cellar,  in  the  middle  of  which  a  fire  is 
kindled,  whereupon  the  cellar  is  well  closed.    The  heat  is  left  to  act 
