All who know about liquor, even a little, know that there are several spirits that are aged in wooden barrels for years. But has anyone thought, why are those spirits aged? or why are those spirits aged in oak barrels? or may be, what spirits are aged and what are not? I am sure many of you must have had these questions popped in your head, and some might have also searched for answers. In this post, we will try and get deep to get the answers to some questions related to ageing liquor.
What is ageing? Why we age liquor?
Ageing is the process of maturing the liquor. It is not just us who matures with age, but a few spirits do too. Ageing brings out the color and flavour of liquors. The estimation says that close to 75% of the final flavour and aroma of the aged liquor’s credit can be for the oak wood barrel in which the liquor was aged. Wood, esp oak helps in eliminating the unpleasant flavours from the spirit. The chemicals of the contained liquid react with wood over the years, hence enhancing the alcohol for consumption. Also, there is a note worthy fact about ageing the alcohol, no two barrels can produce similar results no matter what.
What liquor is aged?
Keeping in mind, whiskey or scotch are not the only spirits that are aged, liquors such as brandy, gin, tequila etc are also aged in barrels. While brandy is also a commonly aged spirit as is scotch and whiskey; gin, tequila, rum, wine does not possess such requirements for ageing but some variants are still aged.
There’s another way to refine the answer to the above question, what liquor is or can be aged. Let’s put it this way, whether or not the liquor will be aged, can be decided by the base of spirit and what distillation process was used to produce it. Distillation is broadly divided into two categories:
- Pot Distillation: Pot Distillation produces the beverages which retain their natural character. These are the spirits that are aged to enhance their flavours and aroma. Beverages like scotch, mezcal and brandy are produced by pot distillation method.
- Column Distillation: Column distillation produces beverages with high alcohol volume & lesser composites to refine the flavour and thus are not so appropriate for ageing. Beverages produced with column distillation method are vodka, London dry gin etc. These are not much appropriate to age as there’s nothing much to refine in the beverage.
But of course, there are some exceptions, like bourbon whiskey. Bourbon is produced by column distillation but yet is aged.
What casks are used for ageing?
There are a few wooden casks that are used for ageing liquor, the most widely used and accepted being Oak Barrels. There are a few more woods that are used to age liquor but are not acceptable by all the spirits. That being the case, the regulations promote the use of oak barrels for ageing but do not prohibit from using only oak. Others such as maple, acacia, chestnut, cherry and hickory are also used to age spirits. The type of wood used for ageing is decided by the ingredients present in the spirit that requires ageing. Going by the above statement, Scotch and Bourbon do require only oak barrels for ageing.
There are hundreds of species of oak, but not all are prominent. European oak and white oak are the two particular conspicuous specie of oaks that are preferred for ageing the spirit. Why Oak? There are several chemical compounds in oak wood that helps in the ageing process of the spirit. These compounds
- hold the cask for years while maturing the spirit.
- release the flavour and aroma in the liquid.
- eliminate any unwanted substance from the beverage.
- hold the cask water tight and still letting the oxygen enter the barrel.
A fact about casks and ageing; not all spirits that require ageing are aged in new casks, some are aged in used casks as well. Let’s say, a bourbon is matured in a new white oak barrel, but for ageing a scotch, a used barrel is preferred (mostly the casks used to age bourbon previously).