﻿416 
  PROCEEDINGS 
  OF 
  THE 
  CALIFORNIA 
  

  

  On 
  the 
  Composition 
  of 
  some 
  of 
  the 
  Grapes 
  grown 
  in 
  Califor- 
  

   nia, 
  in 
  relation 
  to 
  their 
  Fitness 
  for 
  making 
  Wine. 
  

  

  BY 
  JAMES 
  BLAKE, 
  M. 
  D. 
  

  

  Having 
  while 
  in 
  El 
  Dorado 
  County 
  tasted 
  some 
  -wine 
  which 
  evidently 
  was 
  

   superior 
  to 
  anything 
  I 
  had 
  before 
  tasted 
  as 
  the 
  production 
  of 
  our 
  State, 
  I 
  in- 
  

   quired 
  of 
  the 
  maker 
  the 
  variety 
  of 
  grape 
  from 
  which 
  it 
  was 
  produced, 
  and 
  

   found 
  that 
  it 
  had 
  been 
  made 
  principally 
  from 
  a 
  grape 
  known 
  in 
  this 
  country 
  as 
  

   the 
  Ziufindel. 
  Since 
  ray 
  return 
  I 
  have 
  made 
  an 
  analysis 
  of 
  the 
  juice 
  of 
  this 
  

   grape, 
  and 
  also 
  of 
  some 
  others, 
  which 
  are 
  now 
  being 
  propagated 
  for 
  making 
  

   wine. 
  The 
  grapes 
  were 
  grown 
  at 
  the 
  vineyard 
  of 
  the 
  Vinicultural 
  Society 
  at 
  

   Sonoma, 
  and 
  were 
  all 
  apparently 
  perfectly 
  ripe. 
  The 
  varieties 
  analyzed, 
  besides 
  

   the 
  Zinfindel, 
  were 
  the 
  Reimer, 
  a 
  large 
  white 
  grape, 
  the 
  Riessling, 
  also 
  a 
  white 
  

   grape, 
  and 
  the 
  Mission 
  grape. 
  The 
  method 
  of 
  analysis 
  was 
  to 
  take 
  a 
  portion 
  

   of 
  the 
  juice, 
  heat 
  it, 
  to 
  coagulate 
  the 
  albuminous 
  matter, 
  filter 
  through 
  a 
  Bun- 
  

   sen 
  filter, 
  and 
  after 
  bringing 
  the 
  juice 
  to 
  the 
  original 
  quantity, 
  to 
  neutralize 
  with 
  

   a 
  standard 
  solution 
  of 
  potash 
  or 
  ammonia, 
  so 
  as 
  to 
  ascertain 
  the 
  total 
  amount 
  

   of 
  free 
  acid. 
  Another 
  portion 
  of 
  the 
  juice 
  was 
  evaporated 
  to 
  about 
  one-third, 
  

   mixed 
  with 
  alcohol 
  and 
  ether, 
  to 
  precipitate 
  the 
  tartrates, 
  and 
  the 
  alcohol 
  and 
  

   ether 
  distilled 
  off 
  from 
  the 
  filtered 
  juice, 
  which 
  was 
  then 
  neutralized, 
  to 
  ascertain 
  

   the 
  amount 
  of 
  free 
  acid. 
  The 
  amount 
  of 
  sugar, 
  as 
  indicated 
  by 
  the 
  sp. 
  gr., 
  

   was 
  controlled 
  by 
  direct 
  analysis 
  of 
  a 
  portion 
  of 
  the 
  juice, 
  cleared 
  by 
  acetate 
  

   of 
  lead, 
  by 
  means 
  of 
  Fehling's 
  copper 
  test, 
  and 
  the 
  result 
  thus 
  obtained 
  is 
  that 
  

   recorded 
  : 
  

  

  a^ 
  r'- 
  a,,r,o« 
  Free 
  Malic 
  

   Sp.frr. 
  Sugar. 
  ^^j^_ 
  ^^j^_ 
  

  

  Zinfindel 
  1072 
  16.6 
  1.73 
  0.60 
  

  

  Reissling 
  1083 
  18.7 
  1.10 
  0.57 
  

  

  .Eeimer 
  1057 
  14,0 
  1.30 
  0.80 
  

  

  Mission 
  1088 
  21.5 
  0.60 
  0.11 
  

  

  As 
  there 
  can 
  be 
  but 
  little 
  doubt 
  that 
  the 
  development 
  of 
  the 
  ethereal 
  sub- 
  

   stance, 
  on 
  which 
  the 
  aroma 
  of 
  wine 
  depends, 
  is 
  owing 
  to 
  the 
  presence 
  of 
  free 
  

   acid, 
  and 
  more 
  particularly, 
  I 
  believe, 
  of 
  free 
  malic 
  acid, 
  the 
  above 
  figures 
  ex- 
  

   plain 
  the 
  cause 
  of 
  the 
  absence 
  of 
  aroma 
  from 
  the 
  wine 
  made 
  from 
  the 
  juice 
  of 
  

   the 
  Mission 
  grape 
  ; 
  for 
  while 
  the 
  three 
  varieties 
  of 
  foreign 
  grapes 
  analyzed 
  

   contain 
  respectively 
  60, 
  57, 
  and 
  80 
  parts 
  of 
  malic 
  acid 
  to 
  10,000 
  parts 
  of 
  juice, 
  

   the 
  Mission 
  grape 
  contains 
  but 
  11 
  parts. 
  The 
  presence 
  of 
  this 
  comparatively 
  

   large 
  portion 
  of 
  malic 
  acid 
  in 
  grape 
  juice 
  is 
  a 
  fact 
  which 
  has 
  not, 
  I 
  think, 
  re- 
  

   ceived 
  the 
  attention 
  it 
  deserves. 
  I 
  believe 
  the 
  acid 
  itself 
  splits 
  up 
  into 
  an 
  

   ether 
  and 
  an 
  alcohol, 
  and 
  this 
  independently 
  of 
  its 
  action 
  on 
  the 
  alcohol 
  already 
  

   found 
  in 
  the 
  wine. 
  Wislicenus 
  has 
  shown 
  that 
  lactic 
  acid 
  forms 
  an 
  ether, 
  even 
  

   when 
  being 
  dried 
  at 
  ordinary 
  temperatures, 
  over 
  sulphuric 
  acid, 
  and 
  alcohol 
  is 
  

   one 
  of 
  the 
  products 
  of 
  the 
  fermentation 
  of 
  malic 
  acid. 
  There 
  would 
  seem 
  to 
  

   be 
  enough 
  potash 
  in 
  the 
  grape 
  juice 
  to 
  form, 
  with 
  the 
  tartaric 
  acid, 
  the 
  slightly 
  

   soluble 
  bitartrate 
  of 
  potash, 
  as 
  after 
  this 
  has 
  been 
  precipitated 
  by 
  alcohol 
  and 
  

  

  