title_body: How are double and triple casks whiskies matured?
upvoted_answer: The answer is of course: both
  
  Lets take some popular examples...
  
  Balvenie Double Wood
  Matured in Ex-Bourbon casks and finished in Ex-Oloroso Sherry Casks, so (2)
  
  Auchentoshan Three Wood
  Matured in Ex-Bourbon casks for 10 years, then finished for two years in Ex-Oloroso Sherry casks and then finished for six month in Ex-PX Sherry casks, so (2)
  
  Laphroaig Four Oak
  A vatting of whisky matured in four different types of casks: Ex-Bourbon barrels, Quarter casks, Virgin oak barrels and European oak hogsheads, so (1)