At3AS,iSSm'}     Coffee :  Its  History  and  Commerce.  365 
(2)  Fermenting. — The  pulped  coffee  Is  placed  in  piles  for  a  few 
hours  in  order  that  fermentation  may  take  place  in  the  matter 
which  clings  to  the  outside  of  the  parchment. 
(3)  Washing. — It  is  then  placed  in  tanks  of  water  and  vigorously 
stirred  in  order  to  wash  away  the  slimy  material  resulting  from  the 
fermentation. 
(4)  Drying. — It  is  then  placed  on  large  cemented  or  bricked  yards, 
called  barbecues,  and  exposed  to  the  sun.  On  many  plantations 
each  section  of  the  drying  yards  has  a  little  shed  into  which  the 
coffee  may  be  hurried  in  case  of  rain,  and  tarpaulins  or  mats  are 
kept  at  hand  for  use  at  such  times  and  to  cover  the  nearly  dried 
coffee  in  case  the  atmosphere  becomes  very  damp.  While  drying 
the  coffee  is  frequently  turned  by  shovels  and  rakes  or  by  shuffling 
among  it  with  the  feet.  On  some  of  the  large  plantations  the  use 
of  the  drying  yard  has  been  done  away  with,  the  coffee  being  dried 
on  large  shallow  pans  over  steam  coils.  The  advantage  of  this 
method  is  that  it  makes  the  operation  independent  of  weather  con- 
ditions. But  the  coffee  dried  on  the  barbecues  has  the  advantage 
of  being  of  better  quality. 
(5)  Hulling. — This  consists  in  removing  the  parchment  skin  which 
surrounds  each  seed.  In  drying  the  parchment  becomes  brittle, 
and  the  seed  within  it  shrinks  away  from  it,  so  that  it  will  rattle 
like  the  nut  in  a  peanut  shell.  Hence  pressure  will  crack  the  parch- 
ment and  free  the  seed.  The  machines  used  in  hulling  work  on 
this  principle. 
(6)  Milling. — This  consists  in  rubbing  off  and  winnowing  aside 
the  delicate  silver  skin.  This  skin  is  so  thin  and  delicate  that  the 
slightest  touch  is  sufficient  to  break  it,  and  a  little  friction  will 
remove  all  of  it  except  a  little  which  clings  to  the  groove.  Even 
in  roasted  coffee  traces  of  the  silver  skin  may  be  seen  adhering  to 
the  groove. 
(7)  Sorting. — The  coffee  is  now  sorted  according  to  size  in  revolv- 
ing cylindrical  or  conical  sieves,  with  small  meshes  near  the  entrance 
and  larger  meshes  further  along.  A  spiral  channel  or  the  slope  o 
the  sieve  or  the  flare  of  the  conical  ones  carries  each  grain  along 
until  it  comes  to  a  mesh  large  enough  to  permit  it  to  fall  through 
into  the  bin  below.  It  is  easy  to  tell  coffees  which  have  been  sorted 
in  this  way,  because  they  usually  vary  in  size,  contain  some  imper- 
fect grains,  and  some  male-berry  in  the  pod.    The  male-berry  fruits 
