Racked (warehouse): Racked warehouses, also known as “commercial” and “palletised, being with brick, cement blocks or a steel clad structure. Casks are stored either on tall racks with steel rails or the palettes are stacked on top of each other up to 10-12 barrels high. The air circulation between the casks is limited and the difference between the cask on the bottom and on the top might be considerable. In terms on labour, racked warehouses, in particular the palletised, are very handy.
Refill: By law, whisky must be matured in oak casks. Historically, for transporting whisky, whisky distillers used mainly oak cask, which previously contained sherry or any fortified spirit. First fill is the term used for an oak cask filled for the first time with new make (whisky), after it has been emptied from its previous content (sherry, bourbon, Rum, wine, etc). First fill cask allows a fast maturation of the spirit. In addition, the staves of the cask still contain some of the original liquid and will contribute strongly to the flavours of the spirit, as well as its colour (e.g. gold for ex-bourbon casks and amber for ex-sherry casks). As long as the wood is good, casks can be re-used. A second-fill cask is a cask that has previously contained (scotch) whisky that is re-used by the distiller. The term "refill" is unspecific. It only means that the distiller has re-used this cask. Depending on the quality of the wood and the duration of the maturations, a cask can be re-used up to 3- 4 times. Refill cask allows a more mellow maturation. However, when the wood is too old, the wood does not interact anymore with the spirit. See the report "Wood and Finish" for more details.