There are several requirements that need to be met to make Irish Whiskey. The first and most important one is that the whiskey must be completely produced within Ireland. Everything from the brewing of the grains to slow ageing in wooden casks for at least three years must happen on the island of Ireland.
Most people are familiar with the foundations of whiskey, fermented and distilled grains, but there’s a lot more to it. Roughly speaking, whiskey production has five steps: brewing, fermentation, distillation, maturation and bottling.
The first stage of the whole process is making mash out of grain. Mash is a term for a mixture of milled cereals and water or recycled brewing liquor. That mix is then heated and prepared for the next process. The heated mash is called wort or the brew liquor. To make grain whiskey, the milled grains are heated before liquid is added. This creates a continuous flow of wort. Brewing in a batch system is also possible.
The next stage is fermentation. At this point, the wort is cooled and yeast is added to it. The sugar in the brew liquor converts to alcohol at this point – very important when making whiskey – and the result is what is now called the “wash”.
Distillation is next, the point at which the flavours are intensified and the alcohol content increases. The spirit leaving the stills has over 90% volume alcohol, but the amount varies depending on the whiskey. There are two basic ways to distill whiskey, in pot stills or in column stills. The most traditional and most familiar is the copper pot still, used to make Irish Malt Whiskey and Irish Pot Still Whiskey. These whiskeys are generally more flavourful than Grain Whiskeys which are distilled in column stills, like the Coffey Still.
The basics of pot distillation involve adding the wash in batches and heating it all up. The vapour is then collected in a receiving vessel and called the “Low Wines”. If you have a two-stage process, you heat up these low wines again, collect a first running separate to the rest and then take the heart, or the middle cut. This is what will go on to be matured and become whiskey.
If the whiskey is to be triple distilled, the second distillation is not the heart but known as a feint. The feint spirits are distilled again in a spirit still to obtain its heart. All the whiskeys in the Grace O’Malley Captains Range Irish Whiskey are three-stagers.
Most of the time however, if it is a two-stage process, it has a beer column and a rectifying column, while a three-stager has an extractive column in the middle. Column distilled whiskey has a lighter flavour than pot distilled whiskey, the added stage giving more nuances in taste.
Grain Whiskey can only be produced by column distillation. Column distillation doesn’t work in a batch system but instead creates a continuous flow. A stream of wash flows through the column and the perforated plates inside while steam is being added at the bottom. This steam carries the alcohol to the top of the still where it is cooled down again. Then the process is repeated in the next column, and once again if it’s a three-stager, like our Grace O’Malley Irish Grain Whiskey, a little different every time.
When it was first introduced in Ireland, the Irish Whiskey producers of the 19th century did not like column distillation, but it still took roots in Ireland for practical reasons. Column distillation in general creates a more uniform taste that can be varied through changes in the stream volume. This is one of its biggest advantages and the reason why it eventually became popular.
The longest stage is maturation or ageing, which has to last at least three years until the product can be called Irish Whiskey. The whiskey must be matured in wooden casks. Some producers use new casks, which makes the flavour very tannin-heavy, while others reuse casks from other alcoholic drinks. For example, cognac casks were used in the ageing process of the soon to be released Grace O’Malley 18-Year-Old Single Malt Irish Whiskey with Cognac finish, while old Amarone casks from France were used in the Grace O’Malley 18-Year-Old Single Malt Irish Whiskey Amarone Cask Strength.
Maturation plays an important role in the whiskey’s final taste. While all the other stages make the base, the ageing is the part that deepens the flavor and aromas, bringing a richness and complexity to the final whiskey. Whiskey must be fully matured within Ireland in order to be deemed an Irish Whiskey, but once matured, the bottling can happen somewhere else.
All whiskey is put through these same five steps but the devil is in the detail. Every whiskey producer will have their own methods and style and secrets, with different processes, temperatures and even the design of the still all adding to the layers of flavour in the final product.
These are the basics of whiskey production. It is not all that simple, but enough to ask your local bartender a few more specific questions regarding the whiskey they have. Maybe it’ll give you a start into the wonderful world of whiskey. Sláinte!