Blended Irish whiskey
Most of the best-known Irish whiskey brands, including Jameson, Tullamore Dew, Powers, Paddy's and Black Bush, are blended Irish whiskeys, made by blending single pot still Irish whiskeys with column distilled Irish grain whiskeys.
The blending process is identical to that of Scotch whisky, but importantly the different components that these blends comprise sets Irish blends apart from other blended whiskies.
The challenge for the blender is to produce a consistent tasting blend for each brand year after year by a combination of stock management and cask selection. The Irish whiskey blender can use combinations of different grain, pot still and malt whiskies aged for varying periods in different cask types.
The distillers and blenders work together to decide what type of spirit to age in what type of cask - European oak, American oak or virgin oak, and first fill, second fill or third fill casks. How many years the whiskey will then be left to mature in these casks is largely decided by how that whiskey matures, but if the bottled whiskey carries a 12 year old age statement then all the whiskey in that blend will have been aged for at least 12 years.
The Master Blender must have an intimate knowledge of what whiskeys are available, in what quantity, and when they are expected to reach the desired level of maturity. The actual blending or 'vatting' of these whiskeys is the final stage of a process that lasts years and sometimes decades. After the pot still and/or malt whiskeys are mixed with the grain whiskeys the blend is left to marry for anything from two days to a month or more prior to bottling.