Aging
Spirit
To round out or smooth the flavour of your liqueur or commercially
flavoured drinks, it often pays to artifically age your drinks.
When aging your spirit, it is best done between 58-70% alcohol.
This can be done using :
- woods - eg natural or toasted oak, and
- smoothing agents - eg glucose or glycerine syrups.
Hexenwolfe explains that glycerine is safe ...
Glycerine is a naturally occuring organic molecule that is
manufactured by all animals. It is a major part of the animal fats
known as triglycerides. Almost all animal fats such as lard, beef fat
(tallow), mutton fat and other hard fats are triglycerides. These fats
are called tri-glycerides because each molecule is made up of one
glycerine molecule to which is attached three fatty acid molecules. A
mono, or di glyceride fat such as is found in vegetable fats contains
either one fatty acid molecule, or two fatty acids respectively.
Glycerine itself is a molecule made of three connected carbon
atoms, with an OH or hydroxl group at one end. This makes it an
organic alcohol by classification. This also gives glycerine it's
other name of glycerol. Either name is valid.
Glycerine is a natural byproduct of the soap making process. When a
triglyceride fat is reacted with lye, the fatty acids are broken away
from the glycerol molecule. The end product is three molecules of soap
and one leftover molecule of glycerine. This glycerine molecule is
valuable so it is recovered from the soap and used in many ways.
Pure glycerine is a clear, oily liquid with a very sweet taste.
Think of mineral oil that tastes like honey. Another common name for
glycerine is "sweet oil". Glycerine is not digestable by the human
body. The oily texture, and sugary taste make it valuable as a calorie
free food additive. It is used in MANY foods both regular and those
intended for diabetics. Glycerine is also used in many industrial
products. Undoubtedly the most famous use of glycerine is the
explosive nitroglycerine. If a nitrogen atom is attached to each of
carbon atoms in the glycerine backbone, then you have the explosive.
Another famous use of glycerine is in cosmetics. The "oil" in "Oil of
Olay" is glycerine. Many hand lotions use glycerine mixed with mineral
oil and a little lanolin. The most well known in America is "Corn
Huskers lotion".
Moonshiners in the mountains of the USA called glycerine "Beading
oil". A few drops of glycerine added to low proof moonshine would
cause the moonshine to form "beads" around the edge of the jar like
those created when high proof liquor is shaken. The sweet taste also
concealed the harshness of poor quality moonshine. Glycerine is
available from most brewing shops as a finishing agent for wines. It
is also available at pharmacies for use as a sweetener or in
compounding medicines.
Glycerine is a completely safe and 100% natural compound.
Smoothing Agents
Using a non-sweet aging syrup can mellow out your spirit, without
having to store it away for years. Just don't use too much to kill
the character of whiskeys.
Try 20g/L of glucose, or 5 mL per litre of glycerine as a
starter.
Other Tricks
Other little tricks to help round out/mature your whiskey include
adding:
- a tad of orange flavour [essence], and/or
- a bit of sherry (at 1-5% by volume, and Cream Sherry is said to
be best), and/or
- a bit of port, and/or
- a smidgeon of bourbon, and/or
- a tiny tiny amount of honey.
Manuka honey at 1 tablespoon per 1125 mL nicely rounds at the
Drambuie type flavours.
Soak raisins and/or prunes in some 70% alcohol for a while, then
add to brandy.
Try the "liquid smoke" sold by BBQ shops, to enhance that
smokey/peaty flavour (just use it very sparingly !)
Hector advises ...
For Whiskey:
Raisin extract: cover with 90-96% neutral (preferably from molasses or brown sugar) spirit or a week, then strain. I use more of this in rums than in whiskey but it gives both a taste I can just describe like "authentic".
Palisander extract: (deep brown, almost black precious wood, quite similar to ebony -but more expensive- used in making violin "souls", sometimes in guitar's... (How do you call where you mark the chords with your fingers?) The dark wood strips they sometimes use to decorate this and sometimes other parts as well are mad from this wood) cover with 60-70% alcohol from beer, more than a month is better. I think this is the wood that smells more like vanilla I have ever smelled.
Vanillin: It's the artificial thing but it smells and tastes quite different from the real McCoy and gives complexity to the oaky
flavour, from powder, with 60-70% neutral spirit.
Neutral spirit composition for blending: don't use just one type of alcohol (grain, sugar or corn). Using a large part of molasses spirit refined to over 90% gives a lot of complexity. It's a waste, though, not to use it for rum! In a blind testing a thorough whiskey drinker friend of mine chose the one blended mostly with molasses spirit over the one with predominantly grain (rice + malts) spirit in the blend (this guy doesn't drink rum, he actually frowns on it).
Water for blending: the guy I mentioned in the other message, the Johnnie Walker ambassador, told us they don't use distilled water for blending but "purified" spring water. Of course I asked what he meant by "purified" but people were getting annoyed by my frequent interruptions and rapid-fire questioning and the guy answered someone else's question instead. Do use distilled water for diluting rum. It's what everybody around here uses.
Thyme: from 90-96% neutral. Cover for a week some fresh garden (I think it's English) variety then strain. I use several drops only in my 6 gal. little barrels but trying in bottle (700 ml) sizes 3 drops aid a lot in complexity.
Strawberry seed extract: from 90-96% from beer or neutral. I made some extract mostly from the seeds that where left after making some strawberry pulp and straining it with a very fine mesh. Several drops of this help enhance and give complexity to the oaky
flavour
For Rum:
Honey: here they use a lot of this! As much as half a liter per 50 gal. cask (in top of the line rums) so don't spare it.
Black pepper corns: as in whiskey they a give a bigger "woody" touch and more complexity. Several drops.
Lemmon grass: some fresh leaves in 90-96% from molasses. Not more than a few drops. Gives a nice citric
flavour.
Coriander seeds: cover some dried whole corns in 60-70% neutral. Watch out because it has a lot of orange
flavour but it gives richness and complexity, a "tropical" like flavour.
And the ones I usually recommend for rum: cinnamon, cloves and nutmeg. Sorry I can't be more specific and exact on quantities but extract making, in my opinion, isn't too precise a process either. It definitively is the way to go, as you told me first and I more than once recommend people who ask about rum
flavouring, because it's the only way to aspire to some degree of repeatability.
And the last recommendation for both liquors is to get yourself a nice collection of small oak barrels in which you can forget your rum or whiskey experiments and let age, because there's really no good substitute to the old regular ageing. Thoroughly aerating your recently spiced spirits helps fix the
flavour/aroma and gives you a better idea of what it would taste like when more mature. In the case of artificial oaking, I found it is essential to impart the whole range of it's
flavours to oxidize the spirit just after (or preferably during) spicing. I use a beer carbonating stone and an oxygen concentrator for this but I know that an aquarium stone and air pump does the same job, and if you don't have them just splashing the liquor around two containers should do the job.
Maurice writes about some older techniques ...
....here's something I read in a
book called "The Manufacture of Spirit as Conducted in the Distilleries of the UK" by J.A.Nettleton, 1893......
On the maturation of whisky...The raw spirit is placed in a tall
cylinder and a currant of air or oxygen under pressure of one or
two atmospheres, is forced through the spirit. The operation
extending intermittently for ten days. The raw spirit is alleged to
acquire a mellowness of three to five years bonding. These process
help to rid the whisky of off flavours and helps smooth the
taste....
The new whisky is placed in a small vat and alternate currants of
hot and cold air are passed through. Both during and after the
aeration a little sherry or similar wine is added to the spirit,
and so are minute quantities of sulphuric acid or pottasic hydric
sulphate. The latter in view of intensifying the action of the
wine. The whole of the mineral acid and of the salt is afterwards
removed by the addition of a small quantity of powdered and slaked
lime, and the whisky then removed from the small sediment which
occurs.
Les concurs ...
Following comment by Maurice I
discovered reference in Linchines book of world wines reference to
the use of sherry to soften taste and add aroma.
Have been using good quality chestnut teal sherry (medium sweet)
75ml to a litre of spirit and the results have been good. The recipe was Country Squire 2000 and SU Mc Gregors concentrate plus
a little corn syrup. Its worth a try, does well in blind
tastings
Another simple trick is to use corks in your bottles, rather than
screw-caps. This helps the spirits breath a little, and help its
aging. Jack explains ...
it's been a proven fact
(discovered by rum distillers) for years- carbonic acid gasses
formed in the mash, then carried over in the distillate, are
capable of staying in solution, and causing a noticable sharpness -
a period of "breathing" (typically 30 days) can allow this gas to
escape.
Caramel for Colour
Regarding using caramel for colour, Wal writes ...
Caramel, a nice name for burnt
sugar, is legally added to brandy, scotch whisky, rum but by law
not to American whiskey.
How much is used? A site for Georgian brandies gives sugar contents
ranging from 0.7%, 1%, 7%, and 12% i.e. from 1 tsp (6 grams) to 20
tsp (120 g). I would be inclined to start with 1 tsp/litre and add
extra to taste or color.
The French and English caramel is from the Spanish 'caramelo'
which is derived from medieval Latin. The 'mel' part refers to
honey (cane honey). Several sites on the subject:
In a cooking site with a recipe for Trinidad Black Cake (Christmas
Cake) there is a local method for caramelizing sugar - which is
most probably the method used (or was used) for local dark rum:
Caramelizing Sugar
- 3/4 lb sugar (350 g)
- 1/2 cup boiling water
Put sugar in a heavy pot. Stir, letting sugar liquefy. Cook
over a low heat until dark, stirring constantly, so the sugar does
not burn. When almost burnt, remove from heat and stir in hot water
gradually. Mix well, let cool.
Lynne cautions ..
In the interests of preserving the
flesh of anyone who tries this, I feel compelled to add a safety
note: be very careful when you add the water, as it can cause
splatter. Molten sugar on human flesh is not a good feel. The
longer the stirring spoon handle, the better/safer.
Homemade Caramel For homedistillers a recipe for caramel is
to use 2 cups of sugar and 1 cup of water.
See: http://www.jacquespepin.net/members/recipes/basicbrownsauce.html
I have also successfully browned granular sugar in a frying pan to
flavor a vodka which gave it a brandy-like character.
Blending
Jack writes ...
If consistancy (and reproducing
your best batches) is becoming a problem- try a fractional blending
system, like the Solara system used for sherry, and Jerez brandy in
Spain.
The easiest "home method" is like this: set up three bottles of
your favorite spirit. One to drink, one to blend, and one to
age/store. When the "drinking" bottle gets half full, refill it
from the "blend" bottle, which is then refilled from the "aging"
bottle. Never let the "drinking" bottle get more than half empty
before refilling it. This way, the batches will be linked in their
flavor, allowing for consistancy. When the "storing" bottle is
empty- you make another batch.
It will take roughly 4 refills of the "drink" bottle before the
spirits' flavor profile is markedly different- since you are
drinking it as it slowly changes, you won't notice, only someone
who tries the batch at the begining, and then again, after the
first bottle is emptied would notice a change. "House" spirits you
are fond of always having on hand stay more consistant this way- it
also works for wine and cider.
Jack offers the following suggestion ...
I've been doing some more reading
on how commercial spirits are produced and I think I may have found
something that Nixon/Stone still owners may find usefull. As you
may already know, not too many large producers of spirits just
distill, age, then bottle. Somewhere in between these stages is
where blending takes place. For spirits like rum, instead of just
distilling to a high proof then cutting it back with water to make
a light style, many distilleries either make (or buy) a 95% "base
blending spirit" that has no flavor, they then add certain amounts
of a spirit distilled to a lower proof, say, 50-70% alcohol. If
they add a lot of the low proof spirit they get a "dark rum", if
you only add a little you get a "light rum".
If someone were to run a batch of sugar alcohol through a good
reflux still, and get it up to 95% pure, they could set this aside
(undiluted), and then using a pot still (or with the collection
valve wide open on an NS still), they could run of a 10% mash of
grain (for whiskey) or molasses (for rum), and only distill it to
about 50%. Then by adding various amounts of 95% spirit you could
get a dark, heavy rum/whiskey, or a light version of the same drink
(how much water you add is up to you).
From what I have seen this would beat any "flavor essence" on the
market, while providing a spirit that is cleaner, and less likely
to give a hangover because any where from one-fourth to
three-fourths of the final spirit was made from pure ethanol. It
would also add yet another way to "tinker around" with the hobby
distillers favorite drink-from what I've seen this would be a
welcome added step to the production of spirits, because it allows
for something that is unique- a "house style" for the hobbyist that
can be changed easily.
Charcoal & Wood Flavouring
It is estimated that around 80% of the flavour of bourbon and
whisky comes from the oak barrels used to store them in. We can
replicate those flavours by soaking our spirits with oak chips or
shavings. Start by using one teaspoon of oak per litre of alcohol,
and let it soak for a week. Taste test frequently to find the level
of flavour intensity that suits you - eg maybe a little more oak,
or longer, or different % alcohol, or different levels of oak
toasting.
Geoff writes ...
Maybe consider the size and shape
of the barrels that are used to age the spirits you are trying to
emulate. Calculate the ratio of the inner surface area to the
volume of the barrel. Based on some whisky barrels I've seen, I add
about 70 square centimetres of oak per litre of 55% spirit. Keep in
mind that one "strip" of oak has two surfaces that interact with
the spirit. I age spirits in 4 litre glass bottles and add thin
strips (<1mm) of oak that I had wrapped in aluminum foil and
lightly charred on the stovetop. So if my oak strips are 2 cm wide
I cut a total length of 70 cm, but I usually break such a strip
into a few pieces before charring and adding them to the jug. Gives
nice colours and flavours and generally a smoother drink.
For an excellent article on the composition of Oak, and its affect
on maturation, download oak.pdf
(690kB) which was from the Cooperage website http://www.worldcooperage.com.
Donald advises ...
Oaking - Several different flavors
can come from a single type of oak if alcohol strength is adjusted
during maturation. 55%-53% will give vanillins, 40%-50% will give a
mix of vanillins and sugars, 40%-49% will give sugars.
What I like to do is start at 55%-53% for first phase (1 to 12
months) then dilute to 40% (3- 12 months). In this manner I am
adding sugar from the cells of the wood while I marry the dilution
water to the whiskey. This results in rich vanilla oak charater
with silky legs that cling to the side of the glass. The procedure
works well with all types (chips or BBL) and varieties of
Oak.
If you can't buy the commercial toasted/natural oak chips for
flavouring and aging, you can try making your own. Make sure you
use oak or non-resinous wood - using a soft resinous pine will only
give you a retsina. Be ingenious when looking for old oak - locals
here use bits of old furnature etc (after shaving off the varnishes
etc). Smoked manuka timber is particularly good.
To make your own toasted timber, find a tin with a push on lid of
1-2L. Split your timber into thin enough strips to fit your
bottles. Light the pieces, and when well charred, place in the tin.
Place the lid on lightly to snuff out the flames. Add more wood as
it becomes ready, replacing the lid each time. When cooled, push
the lid on tightly to retain the smokey aroma until ready to
use.
Another way is to wrap the oak chips/shavings in aluminium foil,
and bake them in your oven for a while.
The temperature of the toasting will affect the flavour that
develops...

Diagram from http://www.worldcooperage.com
Hexenwolfe writes ..
Jack Daniels is 140 proof grain whiskey when it goes into the
barrel. The barrel is made from American white oak from Missouri.
Each barrel is roasted at 450 degrees for four hours then flash
charred over a 1500 degree gas flame for 4 minutes. It is then steam
quenched to "activate" the carbon (and put out the fire!). The
roasting carmelizes the sugar in the wood before the flash burn
creates the charcoal. The steam treatment not only puts out the
fire, but it causes the charcoal to expand like popcorn creating
trillions of tiny bubbles. This GREATLY expands the surface area of
the carbon. A fresh barrel will have approximately 1/3 inch of char
on the inner surface.
Jack Daniels Whiskey is aged in the barrel for four years. During
this time the barrels are racked in wooden barns. There is no
heating or cooling in the barrel houses. The heating and cooling of
the natural weather cycle in central Tennessee causes the whiskey to
expand and contract with temperature. As the whiskey expands it is
forced into the wood.In the wood it dissolves carmelized sugars, and
tannins. As it contacts, it moves out of the wood and back into the
barrel. The carmelized sugars give the whiskey it's red-brown color.
The whiskey will penetrate approximately 3/4 of the thickness of the
barrel stave. The penetration line is easy to see on an old barrel
stave. Jack Daniels uses each barrel only once. After the whiskey is
removed, the barrel is sold to other whiskey makers, European wine
makers, the makers of tobasco sauce, and the public.
After ageing the whiskey is diluted to 80 proof before bottling.
To answer your question regarding toasting and charring... They
are not the same process. Toasting is baking the wood at 450 to
carmelize the sugars. Charring is actually burning the surface of
the wood to create charcoal. For hobbiests, it is easier to use
toasted chips for flavor, and activated charcoal filtering for
clarifying. These two processes are combined into a single stage
process in barrel ageing.
Jack advises :
Charcoal that can be used to
smooth the flavor of bourbons and rums may be made at home like
this: use either hickory, oak, or sugar maple wood (buying it from
a lumber supplier is easy enough) as these are proven to be
nontoxic.
Split the wood into finger- width sticks about 4 to 6 inches long,
then pack them into an old coffee can that has no more of that
coffee smell or any rust. Pack them in standing upright so there
isn't much space between them. Once the can has a solid layer of
these sticks crammed in together like sardines standing upright,
cover the top of the can with a layer of heavy tinfoil that has a
pencil sized hole in the middle of it. Place this arrangement on
your propane burner (this is not to be done inside!!), and set the
heat on high. After a bit of heating up, some steam, then other
various flammable organic gases will evolve off (if the foil swells
up, make the hole a bit larger- try not to burn yourself). Once
there is no more gas/steam coming out, turn off the heat and let
the can sit outside to cool on it's own with a cover to exclude any
air from getting in. Once cool, rinse any ash off in some cold
water and use however you wish. Do not poke any holes in the coffee
can - that will allow air into the mix and turn all of the wood
into ashes, instead of turning it into charcoal.
Using a pressure cooker to inject steam could also be attempted to
try an make activated carbon, but I haven't tried it.
Jack also writes :
I see people trying to duplicate
Jack Daniel's Tennessee Whiskey (It is NOT a bourbon - the charcoal
filtering procedure was legally recognized as producing a separate
type of whiskey after World War II) on some of the e-groups; the
essential step is to filter the unaged spirit through charcoal (not
activated carbon) that has been made out of sugar maple wood
(see
How to Make
Charcoal at Home by Dan Gill).
The residual sugars in the charcoal give a slight sweetness to the
finished spirit, and the limited absorbing ability of the charcoal
only makes the stuff smoother, but doesn't strip all the flavor
out. I have tasted homemade whiskey and rum made and filtered in
this method, even at "barrel strength" (75%) they were very smooth
- no ice was even needed.
For a "Wild Turkey" style flavour, Wal advises ...
No recipe, but here are some
quotes that might give a lead:
1) Aging technique. "Wild Turkey is distilled and put into new
barrels at a much lower proof than most Bourbons - a costly method
that results in less of the flavor being cooked out. The barrels
are made of the finest new oak with the heaviest char available,
imparting a smoother flavor and a deep amber color."
2) Taste. "best flavors of our premium bourbon, but with real
honey to give it sweetness...." "real honey" "obvious notes of
vanilla and citrus" (this could come from the heavily charred
American oak barrels). "Wild Turkey Liqueur is a sweetened cordial
with honey" - 30%abv.
3) Wild Turkey Liqueur was introduced in 1976 -
htp://www.wildturkeybourbon.com/nest/history.pdf (possibly it was
introduced to compete with honey based Scottish whisky
liqueurs).
It appears to me that a starting point would be to age your raw
whiskey distillate in heavily charred American oak chips, and then
add a pure honey to say 25% sweetness (start with a 250 ml cup/l).
Some orange peel might have been added to imitate Southern
Comfort(?) The vanilla would probably come from the American oak
which has that characteristic.
The "Household Cyclopedia" recommends ...
The flavor of malt spirits is
highly improved by putting 3 1/2 oz. (100 g) of finely-powdered
charcoal, and 4 1/2 oz. (125 g) of ground rice into a quart (1 L)
of spirits, and letting it stand during 15 days, frequently
stirring it; then let the liquor be strained, and it will be found
of nearly the same flavor as brandy.
You can also use virgin wood shavings - the greater surface area
will work faster. Taste regularly to ensure that it doesn't get too
wooded, then filter out when ready.
Wood-essence can be made by soaking the shavings or toasted wood in
70% alcohol for a couple of weeks, then strain them off. Another
suggestion is to pressure-cook the shavings with neutral spirit for
10 minutes at medium pressure, but this sounds risky!).
Brian writes ...
Oak chips in Australian home brew
shops anyway are usually Quercus Alba (American White Oak) and are
applied as per the label. I prefer to use a natural essence as not
only is it more accurate, but is actually "less harsh". To make
this infusion yourself, take equal proportions (by volume) of chips
and neutral spirit at about 70% and soak for approximately one
month, agitating as often as possible or percolate using a pump,
then separate the two and apply solution (tincture) at a rate of
about 10/15 ml per litre, or to taste of spirit at 40%. Or if you
want to be really upmarket, take the tincture and simmer it very
slowly until the volume is 75% less than original and you should
have a fairly concentrated essence. In processing, remember it's
frightfully volatile!!!
Jeanette suggests to use the toasted oak by ...
I am writing to tell you of my way
of aging bourbon ( or whisky for that matter ) We are doing this
one bottle at a time.
- Line up bottles to be used, add your undiluted spirit, and
put in appropriate amount of flavouring. Personally, if it says
10ml per litre, I add 15ml.
- In a stainless steel saucepan, put in amount of water needed
to top up one bottle only. Add one tablespoon of toasted oak
chips.
- Bring to boil, then immediatly turn heat down and simmer. We
don't want to boil off all the aromatics of the oak. At this stage
add a large teaspoon of glucose and stir in well.
- Simmer for about 5 minutes, bring to boil again, then take
off heat and let cool. The mixture should be a lovely brown
colour.
- Strain and add cooled mixture to your bottle of spirit and
it is ready to drink. Or don't strain, and keep the flavour coming
for an even smoother, flavourful drop in the future.
Compare the aroma of your liquor to the conventional, and long way
of aging.
From Cheryl (Victoria, Canada)...(posted on Distillers newsgroup)
The way I make my whiskey is a cup
of virgin (untoasted, french oak) oak to 1 gallon of vodka, and it
sits for a month and gets filtered and is ready to drink. I have
made a scotch tasting whiskey using the same method, only with
toasted oak.
to which Ray Toms added ..
I find that you can overdo the
toasted oak but not the plain oak. I restrict my toasted oak to one
teaspoon for short term oak aging and double it to two teaspoons
for long term (in excess of 12 months) aging whereas I use 3
teaspoons of plain oak for short term aging and 6 teaspoons for
long term aging. Excessive use of toasted oak can leave a burnt
flavour in the whisky.
See below about using casks
Where to source the wood chips ? Donald suggests ...
Whiskey barrel chips can be
obtained by routing the inside a used whiskey barrel. Good results
also come from wine barrels (sherry & port if possible). There
used to be companies (20 years ago) that would convert whiskey
barrels to wine barrels by shaving the charred wood layers out to
toasted wood. They would just give the chips away. FYI - red oak
has good flavor too, it just needs to be used in chip forms because
red oak barrels leak.
Wal writes ...
its worthwhile to extract notes
from University of Nevada, Tourism course 'FAB 362 Distilled
Spirits and Liqueurs': (of which I have a local copy : http://homedistiller.org/detail/362Index.htm because their link is no longer working)
The changes in the spirit during wood aging are caused by 3 types
of reactions occuring simultaneously and continuously in the
barrel.
1)complex wood constituents are extracted by the liquid
2)there is oxidation of components originally present in the
liquid as well as of material extracted from the wood
3)there are reactions between various organic substances present
in the liquid, leading to the formation of more and new
congeners
As with wine, the type of wood is very important and most of the
major spirits have strict requirements. Bourbon whiskey regulations
require that the barrels be new, and that the insides be charred.
This is done by setting the inside of the barrel on fire until a
layer of char is developed. Most other whiskies and other spirits
do not have to be aged in new, unused wood, nor do the barrels have
to be charred. Charring improves and softens the taste of the
spirit and provides both body and color.
The manufacturer will decide what specific type of spirit to make
and there is a close relationship between distilling and aging
strategies.
Anything distilled over 95%abv is legally termed "neutral"
spirits.
Bourbon cannot be distilled over 80%abv
Cognac cannot be distilled over 72%abv
Rum is distilled at 85-96%abv
Scotch malt whiskey is distilled at 70-71%abv
Canadian whisky is distilled at 70-90%abv
The congeners, those secondary products produced during alcoholic
fermentation, consist of acids, esters, aldehydes, fusel oils,
extracts of mineral salts and solids in minute quantities.
Collectively, they do not amount to much from a percentage
standpoint, but they are determining factors as regards product
character.
Esters are volatile substances which give aroma to the spirits
Aldehydes are produced from alcohol/air reactions and contribute to
the character of the spirit.
Fusel oils are higher alcohols and form complex mixtures. Not all
these compounds are desirable, and even those which are, should be
present in specific amounts.
Cognac/Brandy
The use of copper stills is important because the contact between
copper and liquid traps fatty acids and sulphur elements. Cognac
regulations permit French oak only. The barrels are not charred.
Freshly distilled cognac is placed in new barrels perhaps for 16-18
months. Barrels are considered new the first 3 times they are used.
The first of the 3 will be for only a few months since the wood
will impart excessive tannin to the spirit. The second use may be
for up to 2 years and the third even longer. The barrels are kept
filled unlike bourbon and malt scotch whisky. Blending is a key
factor. Both caramel and sugar syrup are legal and regulated
additives. An unregulated practice is the use of oak chips soaked
in old cognac and left in cask for months or years. The purists
regard that the character from this is rather hard and tannic.
Bourbon whiskey
Charred barrel aging is said to impart the characteristic vanilla
and caramel flavor of Bourbon. There are 4 grades of char and each
distiller has their preference. Charring produces a layer of
partially caramelised sugars below the char. Charring imparts color
to the spirit and whiskey stored in new, charred white oak develops
the distinctive red-amber color. Additives are not permitted. The
used barrels are sold to distilleries in Ireland and Scotland.
Scotch malt whisky and Irish whiskey
Most malt whisky is matured in Bourbon barrels, only 4% is in
sherry barrels. One difference between American oak and Spanish oak
is that the American species is harder and consequently matures
whisky more slowly. Spanish oak contains more resin which effects
the flavor. Sherry and bourbon leach out the stronger tannins and
oak extracts, creating a lighter product.
Rum
Maturing is done is used in previously used barrels which may or
may not have been charred. Puerto Rican law requires a minimum of 1
year in wood. Fuller and more distinctive rums result from
increased wood aging of a minimum of 3 years. Caramel is used to
adjust the color. The typical dark color of Jamaican rums is due to
the caramel added. The coloring is produced by heating sugar
solutuins to about 82C (180F) to evaporate the water and caramelize
the sugars.
Wal then asks ...
Could the homedistiller make a
convenient oak essence? In France flavoring/maturation shortcuts
are practiced that homedistillers can copy. In France, four
additives are allowed for cognac and armagnac. See: http://home.tiscali.no/boruud/the1.htm
- Water
To cut excessive alcohol. But vintage cognacs/armagnacs achieve
their 40%abv by slow evaporation (3% a year), so dilution has an
effect on flavor and for traditionalists reduction is a bad word.
For homedistillers a lower %abv distillation will contain more
flavor compounds.
- Boise (e is accented)
A boise essence is made by boiling chips in water and then removing
the chips and slowly reducing the remaining liquid. What one is
left with is a dark brown liquid that is replete with wood flavor
and tannin. Another source mentions infusing shavings in cognac.
Charred French oak chips are also available which act like charred
white Ameican oak chips - more caramelised sugars and vanillin i.e.
softer flavors.
- Sugar Syrup
Used to add sweetness. Normally added if a cognac/armagnac is too
tannic, or to remove any rough edges. It is viscous, and can either
be dark or light. Legally 2% can be sugar syrup. 1 tsp/1
litre(quart) is a good starting point.
- Caramel
A liquid from burnt sugar. It is dark in color and slightly bitter
in taste. It is used to adjust color and establish consistency or
give the spirit the impression of being older and therefore
smoother.
Ideas for discussion:
American whiskey can gets flavors only from the charring of
American white oak staves. American white oak contains less tannins
and more vanillin than French oak. Filtering through maple charcoal
is also practiced, and this has an effect on flavor due to
caramelised sugars in the maple charcoal. A Bourbon essence could
possibly be made by soaking charred American oak chips in
Bourbon.
Rum is aged generally in used Bourbon barrels. Reusing the chips
from making a Bourbon essence and soaking in aged rum (in effect
diluting the wood character) would emulate a used Bourbon
barrel.
Scotch and Irish whiskies are aged by reusing Bourbon or Spanish
sherry barrels. Irish whisky is usually triple distilled (90%abv)
as opposed to the double distilled peated malt Scotch whisky. So
the amount of distilled congeners is different in the two styles.
An essence could be made by soaking in aged whisky for a second
time, American oak chips that were soaked previously in Bourbon, or
European oak chips previously soaked in Spanish dry oloroso
sherry.
The use of sugar and caramel is practiced in all the above liquors
except Bourbon and Tennessee whiskies, and a starting quantity to
achieve smoothness would be 1 tsp/litre. The amount of caramel
(burnt sugar) used would depend on the style required.
Casks
Some wine-making shops sell little oak casks. These really do work
well. Leave your finished liqueur in these for a while, and they
mellow out even more.
See http://www.ibrew.com.au
for a selection of the small casks available in Australia.
If you leave the bung-hole of the cask (once filled) open for
several days, it is said to improve the flavour. Donald disputes this ...
... that taking the bung out of a
barrel might help the whiskey age with a quicker maturation. It
will not! This will only cause the alcohol to evaporate will not
add improvement to the whiskey. This does bring up an important
point of evaporation and the "angels share" the part of the
alcohol that evaporated though the wood and is therefore "lost to
the angels".
The truth is, we don't need any drunken angels! More to the point,
the process of evaporation is distinct from the process of oxidation. Although they are often confused and used
interchangeably. The whiskey flavour can be achieved with out any
evaporation at all, because the flavour component comes from oxidation process alone. The alcohol solubilizes the lignins of the
oak which then oxidize into vanillins. Usuing oak chips with an air
tight container (stainless steel or glass) with a 1/3 to 1/4 air
space at the top, so 100% evaporation is recaptured with 100%
oxidation. This also eliminates the risk of a sour barrel, just
like a screw cap prevents rotten cork spoilage (3%-4%
average).
To price out full sized barrels for yourself, see
Kristofer D offers the following advice :
I have decided the best way to age
alcohol is in a charred barrel. Sometimes prechared barrels can be
found, but they are hard to find. I have charred my own barrels
that were bought at homebrew stores. I also add about a cup or two
of charcoal that has been made from hard wood. A five gallon barrel
works best. Any smaller is too small, and any larger takes to long
to age. When ageing in a barrel about a quart of alcohol is lost
every month. To make up for this you must add to the barrel once a
month. I stop the process when half of the original amount has
evaporated. In a five gallon barrel that takes about eight months.
After this period the alcohol should of mellowed greatly and also
become a golden brown color from the charcoal. I have found the
best why to char a barrel is by putting a small layer of hot coals
in the barrel, and then using an air compressor to blow oxygen into
the barrel. By rolling the barrel slowly a complete charing is
possible. It takes about an hour. You should feel the hoops on the
barrel get hot. Usually hot enough to boil a drop of water. If time
is taken to age alcohol in this manner I guarantee it will be the
best ever. I have done this with apples, peaches, choke cheeres,
and malted barley all grain. Each one came out superb, and the
charicteristics of the fruit wasn't even lost.
Mike P writes :
... Then I bought an oak keg and
tried aging the stuff, well after six months it just wasn't ready
and I was getting err... impatient. So I surmised that the surface
area of the keg was too low compared to the amount of contents to
produce much of a surface contact for the liquor. I added lots of
charred oak chips!! Bout 4 qts to my little 4 gallon keg! My mom
was beginning to wonder when she came home one night and I had the
oven mitts on and was peering into the oven at a cookie sheet full
of smoking oak chips!! However the increased surface area did just
the trick! The now golden liquor was a great tasting and visually appealing product.
An old codger from down the road told me if I added a few (6-10)
black peppercorns to my aging process I would get a new
appreciation! I did and it worked very well, there was no taste
whatso ever from the peppercorns but you got that warm feeling
inside right away after drinking it! It was a nice touch. I have
used it often since then with very pleasing results, careful though and don't fall into the same trap I did, if 10 was good,
then 20 must be better and a 100 would be better yet!!! Ohhhhhh...
the heartburn!!! :-)
How do casks work to mature the spirit ? Its a matter of the wood
letting in a little oxygen, and letting out different proportions
of the alcohols and cogeners present, as well as reacting with some
of the ligins & other substance of the wood. An email from Jim
Busch, to the HBD, offers:
As for the issue of casks and
diffusion of ethanol/fusels:
In whiskey maturation one of the key reactions involves diffusion
of products from within the cask, through the cask wall. Basically
its called a subtractive reaction in this case. The key parameters
that pass through the cask are water and ethanol. The lower the
molecular weight of the compound the easier it is to evaporate
through the cask. This means that it is much easier to reduce the
concentration of ethanol in a cask than it is to reduce fusel
alcohols, as the latter are longer carbon chained alcohols. This
route is also the main factor in DMS reduction in whiskeys. Hasuo
and Yoshizawa, '86, found that the rate of evaporation of a model
whiskey ranged from 32% of the total present in the spirit for
acetylaldehyde to 5% for isoamyl alcohols to 1% for ethyl hexanoate
and acetic acid. So the permeability per compound is quite
different. The texts seem to indicate that in whiskey maturation
there is a net concentration of fusel alcohols and esters of fatty
acids. Similar results apply to cognac production where Ive seen a
reference that indicates a typical loss of 3% per year in both
water and ethanol and a concentration of fusel alcohols.
The chemistry of spirit maturation in casks is quite involved and
interesting. The key reactions are extractions from the cask,
chemical reactions and oxidative reactions inside the vessal (which
continue as the flavanols, tannins, hemicelloses and lignins leach)
and concentration reactions.
Arthur Bell, at http://claymore.wisemagic.com (dead link ?)
says ..
Over the decades OAK wood has
proven itself supreme for ageing potable liquors, became it is semi
permeable and allows the diffusion of alcohol and water through the
thickness of the barrel STAVE promoting minimal evaporation on the
wood surface to the extent of 2% per annum in Scotland. This is the
slow process of maturation so essential to product quality. By
tradition Scotch whisky is not matured in a NEW cask as with
Brandies (Cognac and Spanish) and Bourbon, which historically have
benefited from the new oak extracts. The associated CARAMEL
bitterness of the new oak due to excess TANNINS, LIGNIS, PHENOLS
and RESINS are rarely present and are not appreciated by the
connoisseur of aged malt whisky.
Within the Scotch whisky COOPERAGE two distinctive types of white
oak are employed to fashion barrens from America or from Spain. The
AMERICAN oak (Quercus ALBA) contains less than half of the total
wood extract found in the EUROPEAN oak (Quercus ROBUR). The Bourbon
Whiskey industry uses solely American oak suitably charred to
promote the carmelisation of the wood sugars, so essential to
bourbon character. This pre-treatment of the American barrels with
fire and spirit has become acceptable to the Scotch distiller. The
alternative and much sought after source of pre used cask is JEREZ
Spain which offers both American and European oak casks having
previously contained SHERRY wines.
It will be appreciated, as with all things in life, the expected
enhancement of spirit quality within the cask does not always
materialize and those SULLIED barrels are discarded, no matter how
slight the imperfection. A similarity exist between CORKS in wine
or whisky and wood for casks, that the SOURISH MUSTY - DANK
flavours of bad wood spoils the barrel content.
Charlie Maclean, writing "The
Language of Whisky Tasting" at the Scotch Malt Whisky Society offers ..
...we were delighted to be able to
help Colin Brown, a Manufacturing Scientist undertaking an
Investigation by Analytical Chemistry of Compounds Affecting
Flavour in Single Malt Whiskies, for Napier University, Edinburgh,
with the support of United Distillers.
He writes: "Single malt whiskies are chemically complex and are
known to contain several hundreds of individual components
(congeners) including a variety of alcohols, aldehydes, acids,
esters and phenols, as well as carbonyl-, sulphur- and
nitrogen-containing compounds. Many of these contribute to the
flavour of a whisky and the relative concentrations of each are
dependent upon variations in raw materials and production methods.
Consequently, each single malt whisky is discernable from any
other, including those produced at a neighbouring distillery."
The investigation, which is continuing, began by identifying the
relative concentrations of compounds known to be extracted from the
cask during maturation ('cask-extractive congeners') and a group of
those which arise from the raw materials and during production
('volatile phenolic congeners'). It went on to make a correlation
between these and the perceived flavour of the finished
product.
Four samples of whisky were considered, affording a regional
spread. They were: Caol Ila (Islay), Scapa (Orkney), Rosebank
(Lowland) and Balvenie (Speyside). "Cask-extractive congeners are
of great importance to the overall flavour as well as the aroma and
colour of the finished beverage.
Whisky casks are traditionally treated to thermally degrade the
internal surface of the cask, by firing and charring, for three
major reasons:
- to generate a layer of active carbon which removes
undesirable flavour substances;
- to effect the release and dissolution of flavour compounds
such as vanillin during maturation;
- to yeild colour and phenolic substances which result in new
flavour compounds by oxidative interactive reactions.
The results revealed that all four samples contained similar levels
of the compound furfural, which is associated with a general
'whisky flavour'. The unmistakably woody flavour in the Scapa
sample is attributable to syringealdehyde, which is also present in
Caol Ila, although the dominating flavours of the Islay whisky are
discussed later. The Balvenie chromatogram reveals a high level of
ellagic acid, a compound known for its pungent odour and flavour.
The number and relatively large abundance of lignin degradation
products in the Caol Ila sample would suggest that a heavily
charred oak cask was used for the maturation process. The presence
of 5-hydroxymethyl furfural in Caol Ila would allow the taster to
expect a slightly reddish tint to the whisky.
"Volatile phenolic congeners' primary source is from the peated
malt used in whisky production. So it was not surprising to
discover that the Caol Ila sample had a large number present and in
concentrations greatly in excess of the other whiskies under
investigation. "The presence of phenol at 2.1 parts per million
(ppm), was almost five times that for Rosebank, 20 times that for
Balvenie and 200 times greater than that found in Scapa. Phenol has
a medicinal taste and therefore would be expected to be present in
an Islay whisky. Guaiacol, known for its smoky and phenolic
flavour, was detected in concentrations of 1.2 ppm in Caol Ila, but
was barely detectable in the others. Further investigation showed
that the levels of compounds responsible for 'tarry' and
'disinfectant' flavours (m-, p- and o-cresol) were evident in the
Islay sample but rela tively low in Rosebank, very low in Balvenie
and not detectable in Scapa. However, similar concentrations of the
compound eugenol (perceived as having a flavour not dissimilar to
that of cloves) were determined in both Scapa and Caol Ila. All of
the whiskies investigated contained varying concentrations of
4-ethyl phenol and 2,5-xylenol, which co-eluted and could not be
determined separately. Both of these substances have a powerful
'whisky' flavour."
Mr Brown concludes: "Many other compounds were determined
analytically during this investigation, however their individual
impact on flavour is considered less important than their
contribution to the overall flavour of each whisky. These analyses
are intended to give an insight into the complex chemistry of
single malt whiskies and the impact which each of the many hundreds of compounds has on the characteristics of the finished
product."
Charlie Maclean
Another article, "Whisky
Dectectives" at the Scotch Malt
Whisky Society describes how different techniques for drying the
wood affects how well the spirits mature.
Yue Hung has forwarded some information from an article "The
Production and Aging Of Wine in Small Oak Cooperage" published in
the May 1969 edition of "Wine & Vines¨ ...
Mechanism of Aging
The mechanisms and processes which occur during the aging of wine
in the barrel can be grouped roughly into three closely
inter-related categories. viz. physical, physico-chemical, and
biochemical.
Physical. The most important physical aspect of cooperage in the
aging of wine is its size, because the surface-to-volume ratio
affects the rapidity with which certain processes take place and
the degree to which they influence the character of the wine. Since
all of the aging mechanisms are influenced to a different degree by
variations in barrel size, it follows that there must be one single
optimum size, one ideal surface-to- volume ratio which establishes
the best balance of the wine and which most perfectly favors and
develops the character of the wine during aging. We are,
fortunately, the beneficiaries of centuries of experience in this
area, and we can state with some certainty that, in the great wine
regions of France, at least, the barrel size of 225 to 230 liters
(about 60 U.S. gallons or 50 Imperial gallons) has proven to be the
most perfect. We have little reson to double that this size, or a
size reasonably close to it, will produce the same good results in
other areas. Indeed many of the best wines of California and
Australia (to give two examples ) have been produced and/or aged in
this size cooperage. Similarly, the optimum barrel size for Cognacs
and fine brandies has been established to be 300 liters (about
U.S.gallons or 66 Imperial gallons) It should be emphasized that
half-quarter-eighth- etc.. size barrel are made for the purpose of
storing odd amounts of wine or for breaking down a full barrel when
topping.(Not that wine cant be successfully aged in these small sizes, its simply that the results are not quite so satisfactory,
and that much greater care must be taken, through more frequent
organoleptic examination, to avoid an imbalance in the finished
product)
The most obvious physical process which occurs during aging is the
slow imbibition some of the liquid by the wood and the subsequent
evaporation into the surrounding atmosphere .There are five prince
influences in this process : relative humidity, temperature, air
movements in the area where the barrels are kept, the physical
characteristics of the wood, and finally, the frequency of topping.
This last is important because, where the topping is less frequent
there is more opportunity for an area of wood to become dry and
thus slightly more porous due to shrinkage of the wood tissue The
important of the first three items first emphasized by Pasteur,has
been forcefully demonstrated by Riberean-gayon(3) whose experiments
with 60 gallon oak barrels gave the following results: in good oak
barrels which are cold and humid, the evaporation lose can be kept
to 1 or 2 per cent; in ordinary wineryies it is 4 or 5 percent;and
in poorly designed wineries which are too warm,too dry,and/ or too
much expose to air currents, the loss can be as high as 9 per cent.
The evaporation loss is also greatly influence by the type and
thickness of the wood..
Ian Wisniewski (whisky and spirits writer, and author of Classic Malt Whisky (Prion Books)) wrote about
Oak at Whisky World (big thanks to Whisky World for letting me copy these extracts !)
While oak ageing is an historic tradition, wood management is a far more recent discipline. The benefits of oak ageing have long been appreciated, rather than understood, but it’s only since the 1970s /80s that technical knowledge has supplanted anecdotal theories. With the continual advance of analytical techniques revealing the extent of oak’s influence during maturation, the growing focus on malts, as well as longer maturation terms, wood management has become key.
The archetypal ‘maturation mandate’ is to reach a balance between the beneficial characteristics gained from the oak, while also retaining and developing the individual ‘distillery character’ embodied in new make spirit. As oak ageing can account for up to 60 to 70% of a malt’s eventual flavour, or around 40% in the case of heavy peating, it’s a variable balancing act.
Because different malts have varying ageing potential, longer maturation does not guarantee a finer malt. It’s a case of variations on a theme: yielding different expressions at different ages, as the oak influence intensifies. Moreover, the appeal of a malt may be a case of ‘less is more,’ or ‘more is more’. The ‘right age’ depends on your own palate.
‘Younger whiskies can have great enthusiasm, then after about 10 years you start to get a real mellowing out and balance; for me the balance is complete within 15 to 20 years,’ says Jim McEwan, Bruichladdich’s malt maestro. ‘At 20 years the oak starts to really exert its influence, and at 25 years has a different, really good character, being mellower, rounder, slightly drier, and the heat drops into the chest, not the palate. Between 25 to 30 years the oak, and where the malt is matured, start to play a very important role. Thirty years and onwards there is a huge concentration of oak in the spirit.’
Maturation can be divided into three essential elements. Subtractive maturation, like a ‘rites of passage’ for the ingenu new make spirit, entails the loss of immaturity. Additive maturation sees the oak endowing the spirit with colour, aromas and flavours, while interactive maturation refers to reactions between the spirit and the oak. This is something of a ‘mystical union’ that is not fully understood, yielding an additional range of characteristics that neither the spirit or oak possess individually.
It would be very convenient if subtractive, additive and interactive maturation followed each other in an ordered, chronological sequence. However, these separate elements effectively occur simultaneously throughout maturation, albeit at differing rates.
Oak-derived flavours, for example, can be evident within the spirit from around six months, though losing immaturity may take a couple of years, or even extend over several. Similarly, filling a barrel with spirit can be said to initiate a form of interactive maturation. This reflects the fact that 2 to 3% of the new make spirit is ‘drunk in’ by the staves, possibly even within 48 hours, and subsequently begins to mingle with the ‘wood extractive liquid’ of the cask’s previous contents (although the full effect will, of course, take years to complete). In fact, specific flavours can be attributed to interactive maturation, due for example to the formation of esters.
‘While The Macallan’s citrus and floral notes originate from the new make spirit, the dried fruit notes derive from esters that have been created during interaction with the cask, and also from oxidisation,’ says David Robertson, The Macallan’s Master Distiller.
An initial consideration is the difference between using bourbon barrels, fashioned from American oak, and sherry casks, which are usually produced from European oak, though American oak casks can also be seen in action at sherry bodegas.
European oak, typically harvested from 60 to 150-year-old trees, comprises a looser, more open and porous grain than American oak. This enables the spirit to penetrate the oak more readily than American oak, usually harvested from 40 to 100-year-old trees, which comprises a straighter, tighter grain. The level of tannins, promoting astringency, balance and structure, is also far higher in European oak than in American oak. However, charring bourbon barrels on the inside, while sherry casks are merely toasted, makes the interior of a bourbon barrel more accessible to the spirit.
These technical differences also promote a varying range of characteristics. In terms of colour co-ordination, sherry casks lend an orangey, amber hue, which is distinct from the lighter, golden, straw tint of bourbon barrels. The flavour profile also varies significantly with sherry casks contributing rich fruit (such as raisins, prunes, dates, figs, apricots), fruitcake, fortified wine, almond and walnut notes, spices such as nutmeg, ginger and cloves, not to mention creme caramel, chocolate, and a (positive) sulphurous note, delivered within a rich sweetness.
Bourbon barrels lend a lighter, drier sweetness, with a palate thriving on a medley of flavours: vanilla, honey, various fruits, almonds, hazelnuts, coconut, creme brulee, sherbet, spices such as cinnamon, as well as mint and eucalyptus notes.
The influence of bourbon barrels can be further sub-divided according to the degree of charring. The scale ranges from one to four, beginning with a ‘burnt toast’ effect, and culminating in an ‘alligator char,’ the popular term for a number four, as the surface resembles alligator hide.
Various malt distilleries have an inventory of bourbon barrels with a range of char levels, with a heavier char typically giving greater amounts of vanilla, creme caramel, toastiness and hint of smoke, not to mention more intense colour. Alternatively, a milder char promotes greater sweetness, honey and vanilla, while also endowing the spirit with more body.
The ‘fill’ (referring to the number of times the cask has been filled with spirit) is another important consideration, with many distillers using a ‘recipe’ of different fills to help achieve consistency, or a particular flavour profile. Each fill of a cask results in its degree of influence on the spirit diminishing, until the Master Distiller deems it to be exhausted. If a first-fill cask is said to contribute 100% of its available characteristics, a second-fill will contribute around 60%, with a third-fill (when relevant) dropping to around 35%. Consequently, a second- and third-fill require a longer time-frame than a first-fill to complete subtractive maturation. For example, spirit maturing in a second- or third-fill could require about 10 and 15 years respectively, in order to reach the same degree of maturity as a spirit aged for seven to eight years in a first-fill cask.
However, this does not mean that each successive fill also delivers the same flavour profile, in a progressively milder format. It’s actually a case of obtaining varying, rather than subtler flavours from different fills. Then again, it’s also a case of imparting an ‘appropriate’ influence to the particular house style of the spirit. A lighter, unpeated malt, for example, may principally be aged in second-fill sherry casks, to ensure that the oak influence doesn’t predominate.
‘The first-fill of Spanish oak sherry casks gives a dark mahogany whisky, with rich, woody spices such as cloves and ginger, toffee sweetness and dried fruits,’ says David Robertson. ‘When refilled there is a less robust oak influence and more new-make spirity character coming through, together with more apples, esters and floral notes, while the tannins manifest themselves as light spices (such as cinnamon) rather than oak.’
Similarly, a first-fill bourbon barrel offers a different influence to products further down the line. ‘A first-fill bourbon barrel has more natural sweetness and body, the second-fill allows more products of oxidation to shine through and gives more of a floral top note, though greater oxidation also reflects the damper ageing conditions of a traditional warehouse,’ says Dr Bill Lumsden, Glenmorangie’s Head of Distilleries and Maturation.
Spirit within a first-fill bourbon barrel also has optimum contact with the charred layer, though the char’s active influence does diminish during maturation, not to mention physically breaking down within the cask. (Consequently, when the spirit is emptied after the first-fill, some charcoal also leaves the barrel, reducing the level of char available during the second-fill, which is also less active anyway). This gives a lower level of vanilla and ‘burnt heather’ notes which stem from the char, while simultaneously increasing the level of oak influence.
Another principal difference between successive fills is the level of wood extractive liquid remaining within the staves of the cask. Not simply a case of residue bourbon or sherry, this liquid also incorporates additional wood-derived compounds, which could total around 75 cl in a 200-litre bourbon barrel, or 10 litres in a 500-litre sherry butt.
The largest amount of wood extractive liquid is present within a first-fill, and released during the first few years, with some wood extractive liquid remaining in the second, but only a minimal amount is released from a third-fill. Traditionally this residue was considered an important element, though the nature of the oak, European or American, is now established as the primary influence during maturation, and the wood extractive liquid a supplementary influence.
Jack Daniels Whisky
See Jacks instructions on the Preparing Grain Mashes page for the grain
bill, and his comments in Aging re
passing it through maple charcoal.
Johnnie Walker Whisky
Les suggests ...
My best results came from Top
Shelf Classic Reserve Scotch Whisky.. Top Shelf Classic
Whisky(green label) and Country Squire Whisky 2000. The Classic
Reserve is excellent but requires ageing and is somewhat cloudy to
begin with.Try not to consume before six months.I also tart it up
with some other ingredients. For ease of use, economy and
consistent results the TopShelf Greenlabel Classic is a winner. My
formula for this essence is as follows......
- 1 sachet 40gms Classic Greenlabel Whisky.
- 2.5 litres 44% alcohol .
- 100 mls Glycerine
- 2 teaspoons Eazimix spirit finisher
- 6 teaspoons Virgin American Oak shavings
- 150 mls medium dry sherry (good quality)
Leave in 3 litre glass for at least 4 months then fiter off. To
test place 1 nip in a wine glass and the same amount of Red Label
Johnnie W. in another and compare.I think you will be surprised at
how well your product holds up. You can vary the ingredients to
your taste. Regards Les
Bourbon
Bill recommends the following for a Bourbon made from essences ...
- Soak 2.25 litres 40% in 1 bag of JD's chips and 50 mls of
flavour from Classic American Bourbon Sachet and age for 3
weeks
- Soak spent JD' chips ( from above) in 1.125 litres of 40 %
and flavour with 15ml of Sprits Unlimited premium bourbon mix Allow
this to soak for 3 weeks
- Soak 1.125 litres of 40% in 1 heaped Tablespoon of virgin
oak sawdust, add 1/2 a sachet of Classic Tennessee Flavouring and
allow to soak for 3 weeks
- Combine in the same ratio
- 2 x 1125mls on chips and American Bourbon
- 1 x 1125mls on spent chips and premium bourbon
- 1 x 1125mls on oak and Tennessee flavouring
- Age for another 4 weeks
I find the best thing is to put down a couple of litres a week.
Once the ball is rolling you will have a steady supply of quality
Bourbon.
By the way, this recipe took 18 months of weekly brewing flavouring
and tasting to perfect. Call it a labour of love.
Allowing for a clean starting spirit this will give you a Bourbon
that is best served on its own with just a dash of water to bring
out the flavour.
Brian adds ..
don't forget most of that classic
bourbon taste is vanillin, so you may need to add some quercus alba
[american white oak], liquid oak or some toasted quercus alba chips
to truly get that wood/vanillin effect
Mecakyrios writes ...
Sometimes I like to throw in a
handful of oak chips in about 2 weeks before I distill. I then
transfer the wash and the chips into the still and go to town. I
have found that the oak absorbs (or at least makes me believe) some
of the fusels that we try to cut. The chips also quickens the
distillation times. The oak also adds some interesting flavor when
using it this way.
Smudge describes his technique ...
I recently went right back to my
roots and purchased a Spirits Unlimited 5 litre Simple Still. This
time it's not for distilling washes, but for making
flavourings.
The process is fairly simple – get whatever you want as
flavouring, soak it in alcohol, and distil it.
For the sake of consistency, I use 500mls of base material (corn,
rye, barley etc) and 2.5 litres of 40% alcohol. It sits for a week,
and then I add water to make 4.5 litres and distil it.
OK, for the purists out there, I admit it's not the real thing,
but its getting close. And it's better than anything I have ever
tasted that wasn't from a bottle shop.
I did some research on bourbon to work out where its
characteristic flavours come from:
It is primarily made from corn, but rye is used to give it body.
Much of the flavour, however, is obtained from the barrel. Unlike
whisky, bourbon is aged in virgin oak. Bourbon barrels are charred
with an intense flame, which caramelises the sap producing the
characteristic vanilla/caramel flavour.
I set about combining corn, rye, oak, vanilla, caramel and smoke.
Here's what I came up with:
I distilled separate batches of corn and rye as detailed above and
watered each back to 40%.
I have some 60% alcohol that has been in a 15litre barrel with 2kg
of toasted oak staves. It is black as night and has the warm smell
of dark rum. I distilled some of it (1.6litres at 60% watered back
to 4.5litres volume) to produce a clear liquid with an oak
flavour.
I distilled 50ml of liquid smoke (purchased from the supermarket)
in the same alcohol/water proportion as above.
I added 50ml of concentrated vanilla extract (the expensive stuff)
with 40% alcohol to make a total volume of 500mls.
I caramelised 1 cup of sugar (on the stove) to a rich red/brown
colour and diluted it back with 60% alcohol to a volume of
500mls.
I diluted a bottle of Spirits Unlimited Bourbon to 500mls with 40%
alcohol. Don't substitute the Premium Bourbon, as it doesn't have
the same perfume taste.
I combined the ingredients in the following ratio:
Corn |
600 mls |
Rye |
300 mls |
Oak |
150 mls |
Caramel |
80 mls |
Vanilla |
60 mls |
Smoke |
30 mls |
S/U Bourbon |
30 mls |
The result is quite pale, but it lets you barrel age it without it
getting to dark. It can also be darkened with some concentrated
(un- distilled) oaked alcohol.
It involves some effort but the cost of the flavouring is low at
about AUD$1 per litre of spirits.
Rum
Ed of http://www.MinistryOfRum.com writes
..
I am familiar with a commercial
distiller that pumps clean air into the fermenting molasses wash to
strip some of the H2S formed during fermentation. After
distillation, more clean air is bubbled through the raw spirit to
aerate it more..... This would apply more to fermenting molasses
which has a higher sulfur content than the sugar most people are
fermenting. A small aquarium pump would do the job on for a small
distiller.
Sherry is commonly used as an additive in the rum industry although
most distillers won't admit it. For best results, blend the sherry
and then dilute the spirit to drinking strength before aging.
In the US, only new barrels are used for aging whisky and they can
only be used once. A lot of these once-used barrels end up in the
Caribbean at the rum distilleries, aging rum. The rest end up at
hardware stores and are sold as planters.
A lecture on "Processing
of Jamaican sugar cane" by Robert Lancashire yields ..
How do you get rum from sugar
cane?
The Jamaican Excise Duty Law, No 73 of 1941 defined rum as
"spirits distilled solely from sugar cane juice, sugar cane
molasses, or the refuse of the sugar cane, at a strength not
exceeding 150% proof spirit".
Rum is produced from
sugar cane by fermentation by yeast. The resultant "wash" has
approximately 6% alcohol which after distillation produces rum as a
clear, colourless liquid with about 80% alcohol and a sharp taste.
White rum is essentially this product diluted to 40% alcohol. Gold
rum requires aging in small (40 gallon) oak barrels. The process of
aging is very complex, involving evaporation of some of the pungent
volatile components, reaction of the rum with the oak wood and
perhaps even the absorption of oxygen through the barrel to convert
some of the alcohol to aromatic esters.
The total level of flavour components rarely exceeds 1% of the
total weight (and is normally much lower) in a base of ethanol.
This high concentration of ethanol presents particular problems in
both sensory and analytical studies. Furthermore, the advent of gas
chromatography has shown that most of the components found in
potable spirits are the same and that the nuances of flavour are
essentially attributable to small differences in the relative
proportions of these components.
Note however that expert tasters have been known to name the
district and frequently the actual estate from which the rum
originated, just by the sense of taste and flavour.
In Jamaica, gold rum is generally bottled at proof strength
(Imperial) which is 57 Volume % alcohol. (By comparison, 100 US
proof is 50 Volume % alcohol).
Chemical composition of Rum and comparison to American Bourbon
Whiskey
The following figures were found for a light-bodied rum that had
been aged in charred oak barrels (previously used for aging
bourbon).
Composition of Rum and American Bourbon
Whiskey |
|
Jamaican Rum |
American Bourbon |
Age (years) |
0 |
3 |
0 |
3 |
Constituents |
Concentration g/100L |
Concentration g/100L |
% alcohol |
80.1 |
78.2 |
77.5 |
75.5 |
total solids (extract) |
0 |
87.6 |
0 |
136 |
fixed acids |
0.9 |
8.8 |
0 |
12 |
volatile acids |
1.1 |
20.9 |
3.2 |
50 |
Total acids |
2.0 (pH=4.9) |
29.7 (pH=4.5) |
(3.2) |
(62) |
esters (for years, erroneously called ethers) |
9.7 |
37.5 |
9.6 |
42.0 |
aldehydes |
1.9 |
4.7 |
0.6 |
5.6 |
fusel oils (higher alcohols) |
48 |
66 |
250 |
298 |
furfural |
n/d |
1.6 |
0.12 |
1.42 |
tannins |
n/d |
33.0 |
0 |
62 |
n/d= not detected