Mizunara oak (Quercus crispula) is not the obvious choice for whisky making and maturation. Mizunara oak is rare and expensive to obtain, it grows twisted so is difficult to cut into staves and being both wet and soft is an ordeal for the cooper. If that was not enough the casks have a tendency to leak. Despite all this, whisky producers in Japan are enthusiastic about it, and the wood is starting to attract attention around the world due to its unique flavour profile.
The aging of whiskey in barrels is an essential step in the manufacture of whisky. During storage in oak casks, the new make spirit absorbs and creates the flavours and aromas that shape its later taste. In addition, the whisky gets its beautiful color from the wood. We have already devoted ourselves to the malting, mashing, fermentation and of course the distillation of whisky in our detailed articles on the production, history and science of whisky.
The temperance movements of the last century took a heavy toll on global alcohol production, but outside the trendy speakeasy bars and clubs ostensibly modelled after America’s prohibition movements this is now largely forgotten. Few realise that Scotland had its own, in some cases surprisingly successful temperance and teetotalism movements as well. Prohibition in Scotland In Scotland under the 1913 Temperance Act local areas were given the option of voting on going ‘dry’, that is prohibiting the sale of alcohol.
The lifespan of a barrel depends on what it is used for. Those used by the sherry industry in solera systems can often be decades old, while the bourbon producers, who until recently could only use new American oak casks, only use theirs for a few years before putting them on sell another industry. Virgin casks are sometimes used for whisky maturation in scotland, albiet very infrequently. The majority of the barrels used by Scottish distillers have already have been used to mature or store bourbon, rum, sherry, port or wine and other beverages.
A standard distillery expression is actually the result of blending, or to use the proper term vatting. The industry legally recognises a blend as the mixing of liquid from more than one distillery. Vattings at a single distillery are still called single malt! Vatting is the process of combining multiple barrels of whisky together in order to achieve a consistent flavour. All whiskies unless these are explicitly single cask (and even then on occasion*) are the result of vatting.