Cask and barrel types and their influence
New make spirit is matured in wooden oak barrels. These barrels house the new make spirit for years to come. But also give some of their woody flavors to the new make spirit.
60% of the flavors in the whisky will come from maturation and these cask/ barrels.
The porous aspect is important – it allows the air from around the region to pass in and out of the barrel and affect the character of the whisky. That’s why a whisky from the coast will taste different from a whisky that’s matured inland.
Oak is also full of naturally occurring oils called vanillins. Over the course of the time sitting in the cask, the whisky passes in and out of the oak and draws these oils out with it – adding to the profile and character of the whisky.
There are a couple of different wooden cask:
- Quercus Alba, American oak
- Quercus Robur, European oak
- Quercus Mongolica, Japanische oak
These different kind of oak cask will give you different kind of maturation flavors in your whisky.
The strength of these flavors will depends on:
- The age of the oak cask
- How many times this oak cask is reused.
- What was in the oak cask before the new make spirit went in
- The charring and toasting level inside the oak barrel
What im trying to say is the type of oak used making the cask/ barrel, and that was inside the cask/ barrel before the new make spirit went in is very important for the end product of the whisky and its taste and aromas.
First let me explain more about the different kinds of oak and their flavors.
American Oak
The American oak wood have wider nerves. This allows whisky and flavors to go through much easier than in European oak.
But there is also more angelshare.
Americans will use the word “barrel ” instead of the word cask.
This will give you a lighter and more golden colour.
Them ost common species of American Oak is called American White ook also known as Quercus Alba.
The flavors that will be produced in American White oak will be:
- Honey
- Caramel
- Toffee
- Vanilla
- Baking spices
- Coconut
European Oak
The most common species of European Oak used are:
- Quercus Robur
- Quercus Petraea
European oak wood will have narrow nerves. So this means denser wood. This will allows that the wood flavors are more difficult to release and for the new make spirit to enter the wood. The wooden cask therefor can be reused more often and there will be less angelshare.
Also the flavors in the wood will be more difficult to transfer into the whisky.
The most popular types of European cask used are Spanish and French cask.
The flavors that will be produced from Europeans oak will be:
- Quercus Petraea
- Quercus Robur
With notes of spices (nutmeg, cinnamon), dried fruits (sultanas, prunes) and citrus peel.
Japanisch oak
Quercus Crispula also known as Japanisch oak also know as Mizunara oak, has been used since the 1930’s to give Japanese whisky its unique set of flavors as a result of the incredibly high vanilline count.
However, the Mizunara oak is very porous and prone to leaking and spilling precious whisky. That is why Japanese oak isn’t good for long term aging. As such, most Japanese whisky is aged in sherry cask or bourbon barrels and then given a second finish in Mizunara oak to gain its distinctly Japanese characteristics.
The flavors that will be produced by Quercus Crispula Japanische oak will be:
- Sandel wood
Sherry cask
Bourbon barrels
The most common used American barrels are Bourbon barrels. Bourbon barrels are cheaper because by law, the American distilleries can’t reuse their barrels. This will allow Scottish and Irish distilleries to buy these barrel relatively for low cost.
The Bourbon barrels gives flavors of:
- Lots of caramel
- Honey
- Light to amber gold colour
Expirimental cask and barrels
- Bourbon | vanilla, caramel, toffee, coconut, fresh fruit
- Cognac | dark, rich fruits, spices, nutty, caramel, vanilla
- Rum | molasses, spices, caramel, dried fruit, vanilla, oak
- Perdo Ximenez | dark fruits, treacle, dates, syrup, very sweet, nutty
- Madeira | sweet, tropical fruit, cherries, floral, spice
- Manzanilla | dry, costal/salty, dried fruit, dry, citrus zest
- Olorosso | ripe fruits, dried fruits, woody, nutty, spicy, sweet
- Marsala | sweet, nutty, spicy, brown sugar, apricot
- Chardonnay | buttery, tropical fruits, green apple, fresh pear
- Bordeaux | dark fruits, red berries, peppery, nutmeg, honey
- Sauternes | sweet, apricots, peaches, zesty, honey, nutty
- Port | sweet, citrus, red berries, dried fruits, dark chocolate, spiciness
- Burgundy | very fruity, lightly sweet, lightly dry
- Limousin |
- Moscat | floral , sweet, citrus, peach
- Amarone | tannins (bitter), dry, raisins, ripe fruits
- Tokaji | light fresh fruits (citrus, mango), very sweet
- Tempranillo |
- Barolo | fruits, tannins (bitter), dried fruits, heavy aromas
- Vigian oak | vanilla, cloves, caramel, wood spices
- Amontillado | sweetness, nutty, dry, fresh, acid
- Fino | light fruits, sweetness, dryness, light wood
- Pedro Ximenez | very sweet, dark fruits, raisins, syrup
- Palo Cortado | rich, sweet, dry, sweet spices, fruits
A good marriage is a good thing
A marriage will be two different cask/ barrels will be put together in a bigger blending tun.
So you have a American oak barrel with a 1st Fill Bourbon and a European oak Spanish olorosso sherry cask. You will put these two casks/ barrels together and you will have two different kinds of whisky together inside a new cask/ barrel. This is called a marriage.
The shape and size of a cask has a significant influence on the maturation of whisky, because it will dictate the ratio of the wood coming into contact with the spirit, e.g. a smaller cask will have a higher ratio of wood contact to spirit than a larger cask. Therefore, the wood will interact with the spirit more rapidly or slowly, depending on the size of the cask. This not only influences the rate at which the whisky matures, but also the final characteristics of the whisky.
Read more about shapes and sizes of casks and barrels
Different kind of finishes
Recent years have seen an increase in the use of all manner of different casks to mature or finish whisky, which has created some very interesting whiskies and an even greater variety of options.
Every distillery will have its own cask maturation or finishes.
Look at the topic experimental cask and barrels for flavors notes you will encounter in these finishes.
How long will a cask or barrel last?
Well this depends on the quality of the cask/ barrel. Their are cask/ barrels that will only be used for 10 -15 years and there are cask/ barrels that will hold a whisky for more then 50 years.
A warehouse manager is responsible for checking and managing all cask/ barrels in the warehouse and needs to know where every cask/ barrel rests. If a cask/ barrel will be at the end of their life spend they need to empty it out and restore it in a different cask/ barrel or bottle the whisky.
The cask will then be taken apart and the good parts will be reused and the other parts will be burned or sold.
How many times will a distillery re-use a barrel or cask?
There is a 1st Fill cask / barrel
And there is a refill cask / barrel
This will mean that a 1st Fill barrel of cask will give more flavors to the new make spirit or whisky than a 2nd Fill or refill cask / barrel.
Not only the color of the refill will be less but also the aromas inside the whisky will be weaker than a 1st Fill cask/ barrel.
A cask/ barrel is expensive and will cost a distillery lots of money if they only use them once. This is why a distillery manager will reuse their cask/ barrels by:
- Repairing them
- Re-charring and toasting them the cask/ barrels
This allows the distillery to refill their cask/ barrels with new make spirits of use them as finishing cask/ barrels.
There is also a choice if the new make spirit need to be stored for more than 30 years you don’t want to use a cask or barrel that gives too much wood flavors. This will have a negative effect on the whisky. So then a distillery manager will use older or refill barrels to tore their whisky for long term.
After 30 years or more a cask will be obsolete and the cask will be sold to companies that make furniture or re-use the wood.