What's barrel-ageing, and how does it change your gin?

This month, in addition to their bottle of Windspiel Gin, our members received samples of Windspiel’s Premium Dry Gin Reserve and Barrel Aged Potato Vodka. Both spirits, as the names suggest, have been rested or aged in wooden barrels – the gin in oak and the vodka in ash.

Barrel ageing may be something more familiar to you in relation to whisky, bourbon, Cognac or even wine, although it is becoming increasingly popular to age other spirits, such as gin and vodka, and even to age pre-mixed cocktails.

But what is the purpose of barrel-ageing, and what does it bring to the party?

The practice can be traced back thousands of years to ancient Roman times, when the Romans discovered that the wine stored by the Gauls in wooden containers tasted better than the wine they had until then been storing and transporting in clay amphorae.

Skip forwards to the era of transatlantic voyages, and pretty much everything was being stored in oak barrels, as they are sturdy for transportation, cheap and hold natural antibacterial qualities. Again, people noticed that the alcohol stored in the oak casks mellowed as time went on, with spirits losing some their harshness and taking on spicy, vanilla and nutty notes.

Gradually, people began to understand that the effect was the result of the spirit reacting with the wood it was kept in, which essentially becomes an ingredient of the final tipple.

Today, ageing is legally stipulated part of the production of many spirits, including Scotch whisky, bourbon and cognac. Distilleries compete to employ the best master blenders, highly skilled craftsmen who practice the art of getting the best flavours from the marriage of wood and liquor.

Ageing barrels are most commonly made from oak, but can vary widely in terms of size, age and material. New casks impart flavour most quickly and their effect naturally decreases on subsequent uses. It’s also possible to use casks to age spirits that have previously held different contents (sherry or wine for instance).

While barrel-aged gin might not be something that you’re familiar with, in fact at one point, pretty much all gin was ‘aged’ in some way – not in order to change or improve in the flavour, but simply because it was shipped and stored in barrels. The 1861 Single Bottle Act changed all this, as it allowed distillers to sell gin in glass bottles instead of barrels for the first time.

It is once again becoming popular to barrel-age gins and, increasingly, vodka. However nowadays this is done very much with the intention of using the barrel as a key ingredient in the same way as in whisky ageing – albeit gin and vodka can be aged quicker than whisky, in a matter of months if required.

Another trend that has re-emerged recently is aged cocktails. In the early 20th century these were apparently very popular, with bottled ‘Club Cocktails’ being advertised as “aged in wood to exquisite aroma and smoothness”.

Over the past few years, kick-started by UK drinks maestro Tony Conigliaro, aged cocktails have once again become all the rage in the hottest cocktail joints - mixed in batches by skilled bartenders and then left to rest in barrels. The ageing process for cocktails is shorter than even for gin – a matter of weeks or even days – but the effect is essentially the same; mellowing the liquor and giving it a rounder, richer taste.

As you sip your Windspiel Premium Dry Gin Reserve and Barrel Aged Potato Vodka, see if you can identify the different effects the oak and ash barrels have had on the aroma, taste and mouth feel of each of these spirits. As with most things (at least we like to think), you might just find they’ve got better with age…