We are all guilty of judging whisky by its colour, but what can the colour of whisky actually tell us? Our eyes often impact our thinking and subject us to tasting notes before we even take the first sip. Also, darker whiskies are often perceived as better quality, more complex and well-aged. Unfortunately, this is not always the case at all. Let’s look in more detail at where the colour comes from.
What impacts the colour of whisky?
Oak
When it comes to the type of oak used for ageing whisky, there are many parts to the colour contribution. Most whisky casks are made from either American white oak or European oak. European oak comes from northern Spain, Portugal or France. All wood types have oils and tannins in them which will contribute to the flavour but also the colour of the whisky. The spirit draws colour out from inside the oak. American oak imparts a lighter golden colour to whisky, while European oak makes it reddish, amber-like. Although none of that would happen without the toasting of the cask.
Toasting & charring
All casks are toasted, but they are not necessarily charred. A new oak cask goes through a heat treatment, toasting, before any liquid is put inside. Toasting caramelises the wood sugars, releasing flavour and colour compounds. A lot of the colour comes from the tannins in the oak.
The next step is charring of the casks. There are different levels of toast and charring, and each distillery has its own preferences. Bourbon barrels are often charred for around 40 seconds, but in some cases they may be charred for up to three minutes. The higher the char level, the more it allows the spirit to get into the pores of the oak. The charcoal itself doesn’t colour the spirit.
The charcoal will eventually stop working and the cask will need to be treated again. As casks are very expensive, rejuvenating them allows further usage of the wood.
Number of fills
Bourbon is aged in new oak casks that have never seen another liquid. In the scotch whisky industry, casks can be used several times. These refilled casks will have a lesser impact on the flavour and colour of the next batch. It’s like a teabag – the more you use it, the less it gives. Therefore, it is possible to have an older whisky with very little colour. The distillery has simply used a refill cask which transfers less colour to the spirit due to its long life in the whisky business.
Previous liquid
If the cask was previously used for ageing Bourbon, the next spirit put in it will take in those colours from the wood. These can be anything from straw to gold. Red wine casks will bring in darker hues, but it is good to remember that the colour will change over time due to oxidation. For example, it can start off as deep red but become a shade of brown with air, or even pinkish, as often happens with ex-Port casks.
Knowing the previous liquid can impact our thought process as we expect certain colours from specific liquids: Pedro Ximénez and Oloroso sherries are dark in their appearance, Sauternes is peachy yellow, Port is deep red, and so on. Of course, they all will impact the colour of the spirit in the cask, but the age of the cask, its toasting, and the oxidation will all work their magic in changing the colour of the spirit.
Some distilleries not only blend several casks together to reach their ideal flavour profile, they also use various cask types in the blend. Take Raasay Distillery as an example. They use three types of cask in their core whisky: fresh Chinquapin, ex-rye whiskey and ex-Bordeaux red wine. Chinquapin oak (Quercus Muehlenbergii) brings a darker colour to the spirit. The distillery carefully analysed the various char and toasting levels to find the right balance they were looking for.
They use Chinquapin with high char and high toast to increase the internal surface area and allow more spirit contact with the wood. This also creates a darker colour. When it comes to the ex-Bordeaux barriques, they contain two types of French oak: Quercus Petraea and Quercus Robur. The latter in general has a wider grain, which lets the spirit deeper into the oak, allowing it to impart more colour. And, of course, the red wine soaked into the wood will contribute too.
To help understand the different levels of maturation, read my previous blog post about cask influence.
Caramel colouring
Every whisky lover’s disappointment. For me, part of the fun is to compare the colour of different whisky releases. Unfortunately, some distilleries use E150a caramel colouring to create a consistent colour for all their whiskies, or at least for specific batches. It is not supposed to have an impact on the flavour profile, but those with more sensitive palates say they can taste the additive.
Whisky blenders combine several casks to find the right balance of flavours to keep their core releases consistent. Sometimes even if the flavours are on point, the colour is not, and the colouring agent will help to correct that.
However, I think the main reason for using E150a is market demand. Many Asian markets expect their whisky to be of a certain colour, so to help sales, these distilleries add colouring.
Many consumers still associate a darker colour with age, and older whiskies are (mistakenly) assumed to be of better quality. It’s a vicious circle really.
Overall
It is generally accepted that around 60–80% of the flavour in whisky comes from the cask, but its colouring power will diminish over time: the more the cask has been used, the less colour there is left inside. Also, the size of the cask matters. Take an octave cask, for example: due to the small surface area, the spirit will extract flavours and colours easier. So, the whisky could have a darker colour but be young in age.
There are several older whiskies with lighter colours, yet the flavours are complex and enjoyable. The texture of the spirit can be rich and oily, and the palate just keeps on giving. Perhaps due to the high use of sherry casks in older whiskies, people associate the colour with age. Next time you see an older, lighter whisky, give it a try and you might just start changing your views on the importance of (dark) colours in whisky.
I also recommend you try tasting whisky from a black glass to see how much your eyes deceive you. We connect so many flavours with certain colours, so trying the spirit blind allows your other senses to work harder. Nose it and sip it a few times before transferring the spirit into a clear glass and trying it again.
Don’t judge the book by its cover!
Does the colour of whisky influence your thinking? Do you avoid lighter whiskies?
