io8 
Cacao  Shell. 
/Am.  Jour.  Pharm. 
February,  19 19. 
The  quantity  of  shell  produced  every  year  is  sufficiently  great 
to  make  the  subject  of  interest  to  those  who  have  to  consider  the 
scientific  use  of  waste  products.  By  calculation  from  the  official  re- 
turns on  cacao,  the  world-production  of  cacao  shell  is  found  to  be 
about  36,000  tons  per  year,  of  which  Europe  consumes  22,000  tons. 
The  consumption  in  Great  Britain  in  191 6  was  4773  tons. 
The  raw  cacao  beans  of  commerce  are  about  the  size  of  almonds 
and  have  a  thin  skin  or  shell.  This  averages  about  12.5  per  cent, 
by  weight;  the  percentage  varies  with  the  size  and  method  of  pro- 
duction of  the  beans.  Thus,  when  the  shell  has  been  washed,  as 
in  the  case  of  the  cacao  from  Ceylon,  it  amounts  to  about  8  per 
cent.,  whereas  with  Trinidad  cacao,  which  is  clayed,  it  varies 
around  15  per  cent. 
In  the  cleaning  of  the  beans  a  small  amount  (about  0=2  per 
cent.)  of  loose  shell  fragments  is  separated.  The  shell  cannot  be 
easily  separated  from  the  bean  in  the  raw  state,  but  after  roasting, 
the  shell  no  longer  adheres  to  the  bean.  It  has  apparently  always 
been  the  custom  to  remove  the  shell,,  and  to  use  only  the  kernels  for 
the  preparation  of  cocoa  or  chocolate ;  thus  Willoughby  in  his 
"Travels  in  Spain"  (1664)  writes  "They  first  toast  the  berries  to 
get  off  the  husk,"  and  R.  Brookes  in  his  "  Natural  History  of  Choco- 
late "  (1730)  says:  "The  Indians  .  .  .  roast  the  kernels  in  earthen 
pots,  then  free  them  from  their  skins,  and  afterwards  crush  and 
grind  them  between  two  stones." 
After  roasting,  both  the  shell  and  bean  are  crisp  and  brittle,  and 
the  small  hard  radicle,  or  germ,  is  loose.  All  that  is  necessary  to 
get  them  in  a  suitable  condition  for  separation  is  to  crush  the  bean 
with  as  little  breaking  down  to  powder  as  possible,  so  that  the  shell 
is  in  large  solid  fragments  (nibs).  This  is  frequently  accomplished 
by  passing  through  rolls  at  such  a  distance  apart  that  the  bean  is 
cracked  without  being  crushed.  It  may  also  be  effected  by  using 
a  serrated  cone  revolving  in  a  serrated  conical  case.  It  is  usual  to 
pass  the  broken  bean  into  a  germ  separator ;  in  these  machines  use  is 
made  of  the  uniform  size  and  rod-like  shape  of  the  germ  to  effect  sep- 
aration. The  germs  so  obtained  naturally  contain  some  nib  and  fine 
shell,  and  this  mixture  is  known  as  "  smalls."  The  large  nib  passes 
on  to  the  husking  machine,  in  which  the  nib  and  shell  are  separated 
by  winnowing  in  a  powerful  current  of  air,  the  large  nib  falling 
through  the  current,  whilst  the  shell  is  blown  into  another  compart- 
ment.   Both  nib  and  shell  pass  down  revolving  "cylindrical  screens, 
