Jameson 21 year old released in 2021 was initially matured in ex-bourbon and oloroso sherry seasoned casks at the Midleton Distillery for 18 years before being blended and re-casked into ex-bourbon barrels for an additional three years. These casks were then married with additional pot still whiskeys that had fully matured for over 21 years in first fill oloroso sherry casks and bottled at cask strength.