If you are beginning to collect whisky, or if you have a collection already, it is vital that you know how to store your bottles correctly to ensure they maintain their quality and value.
Read on to find out why storage is important and our 4 steps to successful storage.
Why is storage important?
Correct whisky storage can dramatically impact the condition of your bottle, helping to maintain value and quality should you look to eventually drink the bottle. It is also an easy and cost effective fix.
Why Is Storage Important For Drinking?
Even if you are storing your whisky with the intention of drinking it then you still need to store it correctly to ensure the quality is maintained. If the whisky is left in unsatisfactory conditions the flavour, nose, colour and finish can all be impacted – as was seen in the incredible storage experiment conducted by Mattias Klasson.
Klasson’s two year experiment showed the significant impact storage conditions can have on the quality of a whisky. Every whisky in the experiment was impacted in some way by the sub-optimal levels compared to the reference.
Why Is Storage Important For Selling?
While you might not be planning to drink the bottles from your collection, the impact on perceived quality does impact the value of your whisky. Correct storage impacts the future value of your whisky because whisky that looks like it has been stored badly will be worth less.
Incorrectly storing your bottle can lower the level of the whisky in the bottle due to evaporation, it can also bleach the whisky and damage the label, all of which impact the value of your bottle. The level refers to where the whisky sits in the neck of the bottle. A good level would be well into the neck of the bottle, whereas a poorer level may sit in the shoulder, the wider area.
How Are Whisky Bottles Sealed?
In most cases, whisky bottles are sealed with a cork and a capsule. Cork has a number of qualities that makes it best suited to whisky bottles, as well as other alcohols such as wine, but that doesn’t mean it is a perfect fit.
The first and foremost reason for using cork is that it is impermeable to moisture. Whilst cork is not permeable to moisture, it is permeable to gases, in particular oxygen. It is this attribute of cork that ensures it is a perfect closure for wine bottles and less than perfect for whisky. The fundamental difference between long term wine storage and long term whisky storage is that where wine continues to mature once it is bottled, whisky does not. It is the oxygen that slowly travels through the cork that allows wine to continue maturing. However, as all maturation for whisky is done in the cask, oxygen that enters a whisky bottle has a long term negative impact.
So if the cork alone isn’t perfect protection for your whisky bottles, how can you improve it? There are four conditions of storage that can help ensure a better seal for your whisky.
The Four Conditions of Whisky Storage
Store Bottles Upright
The first requirement for good storage is that the bottles need to be upright. Some people assume that whisky can be stored the same as wine, which they put laying down in racks, but this not the case. Whisky is bottled at a much higher alcohol concentration than wine, at a minimum of 40% ABV as opposed to an average of 12% for wine. This causes an issue when the bottle is laying down as the alcohol will degrade the cork. Storing the bottle upright ensures that there is head space between the spirit level and the cork to prevent the cork from breaking down.
Storing the bottles upright can often make collectors worry about the cork drying out. This has led to a myth developing that turning your bottles upside down briefly once a year will wet the cork and create a better seal. However, this is not the case. David Cox, former director of Fine & Rare whiskies at Edrington, expressed that all whisky will have an inevitable amount of evaporation and that would be enough to keep the cork moist.
This is true of good quality corks but often whisky bottles are sealed with cheaper, mass produced cork that will dry out more easily. In this case, relying on the evaporation alone may not be adequate in keeping the cork moist enough to maintain a good seal. This leads us to our next condition of storage: sealing your bottles.
Sealing Your Bottles With Parafilm
In order to create a tighter seal to prevent excess evaporation and to stop the cork drying out, you can use a barrier such as parafilm to seal your bottles.
Parafilm is a thin thermoplastic film that is largely made of paraffin wax. Parafilm has been used for decades in laboratories to seal test tubes and petri dishes and is now being extended to use in other industries. According to the producer, Bemis, parafilm prevents moisture and volume loss due to its material composition and tight seal and also doesn’t release from glassware. This has previously made it perfect for sealing healthcare and scientific equipment and now makes it suited to sealing whisky bottles. Due to its composition, parafilm can stretch up to 200% and will hold to any irregular surface which ensures that any gaps in the capsule are sealed.
Adding a Parafilm seal reduces the chance of evaporation and oxidisation because it is relatively impermeable to oxygen. A square metre of Parafilm over an open vessel would only allow 150cc of oxygen through in 24 hours. When you seal a bottle with Paralfilm only use 0.005 m2 – and this is wrapped many times over and over – so not only is the surface area miniscule, you are adding multiple layers AND you are applying this over a well sealed bottle.
As a result Parafilm adds a further layer of security to your bottles so you can store your bottles long term with confidence.
We currently have parafilm listed on our shop in a 15 bottle sealant kit
Storing Out Of Sunlight
Sunlight can alter the colour of the whisky and dull the flavour as the ultraviolet rays will bleach the whisky over time. The loss of colour issue is most problematic for whiskies with caramel colouring added but all whiskies should be kept out of sunlight regardless. Isabel Graham-Yooll, head of spirits at BI Wines & Spirits, warns that direct sunlight can change the colour of a bottle of whisky in just four to eight weeks. Once this change takes effect it is impossible to get its original colour back, and so storing out of sunlight is of vital importance.
In addition to altering the colour of your whisky, direct sunlight can also affect the taste. If left in direct sunlight for a long period of time, the sun can eventually degrade the compounds within the whisky resulting in it tasting rancid. Should you decide one day that you would like to drink your whisky collection you may find it doesn’t taste as good as it once did. This also becomes problematic when it comes to selling your collection too.
Aesthetically, direct sunlight can cause the label on your bottle to fade. Whilst this doesn’t affect the whisky in the bottle, it does result in a label that is harder to read and which doesn’t look as good as it once did. This will reduce the value of your bottle should you decide to sell it at any point. One bottle prone to this was the Macallan 25 Year Old Anniversary malt. The red ‘25’ which covers a large portion of each label fades to a very pale pink when it has been exposed to sunlight, whereas bottles kept out of the sun will have a much darker hue.
Finally, keeping your bottles of whisky out of direct sunlight also ensures that they don’t experience drastic temperature fluctuations. Temperature fluctuations can cause problems because whisky expands when it is warm and contracts when it is cold. If whisky is subjected to rapid temperature fluctuations it can cause bottles with a high fill level to pop as there isn’t enough room for the whisky to expand. Furthermore, when whisky is left in a cold environment for too long it can go cloudy. Whilst this is commonly reversible when brought back up to room temperature, it should be avoided.
Storing At The Right Humidity
If the storage space is too humid, it will become damp. Excess moisture in the air becomes an issue for whisky bottles as it degrades the label and encourages bacteria and mould growth. High humidity can also result in the glue of the label breaking down completely and the entire label will peel off the bottle. This can drastically reduce the value of your bottle as the label will become discoloured or ripped if not peeled off altogether.
However, this doesn’t mean that an air conditioning unit should be used to strip all the moisture out of the room. This will encourage higher levels of evaporation and a resultant lower spirit level.