TamdhuWhisky
Distillery

The Tamdhu Distillery |
MALTINGS
TOUR
Arrive
on site and sign in. Prior to tour, walk around plant to see
where stages of process are. Check variety of Barley coming
into site and where it is coming from. Meet visitors and make
introductions.
Proceed
to Barley Intake We
receive barley from grain merchants examples (Grain Farmers,
Dundee) or (Highland Grain, Black Isle above Inverness). Barley
received generally comes from eastern side of Scotland. We
receive approximately 16-17 thousand tonnes of barley each
year and usually we usually receive two 25 tonne lorries per
day. When the lorry arrives on site it is weighed on weighing
bridge and is sampled using sampling machine above weighing
bridge known to us as ‘THE NODDING DONKEY’. These
samples are then taken to Barley Office to be checked before
unloading of barley. Each load comes with its on ‘Passport’
(necessary documents detailing variety of Barley, sampling
results etc.).
Barley varieties:- Cellar / Optic / Golden Promise. After
checks have been carried out on load and load is accepted,
it is then unloaded into the barley bins. Each bin can hold
up to 100 tonnes of arley and smaller bins will hold up to
75 tonnes. We'll also see the malt bins which can hold up
to 80 tonnes of malt with smaller bins holding up to 60 tonnes.
Once the barley is off loaded, the Haulage lorry will then
upload a load of malt. We feel it makes good sense to use
lorries for off loading barley and then to load malt - which
is then delivered to company sites.
We
will then proceed to barley office where we will explain its
function and also what happens to the samples taken from load.
Barley Office Here in the barley office,
it is necessary to check the quality of the barley coming
onto our site. There are several checks carried out from samples
taken from load prior to unloading on to site, some of these
are germination / screening/ insects, further checks like
moisture and nitrogen (low in nitrogen-high alcohol - high
in nitrogen-low alcohol, so we are looking for low in nitrogen
barley) checks are carried out by main laboratories (Macallan
/ Simpsons, Berwick)
First
and last check of GERMINATION takes about 20 - 30 minutes.
One hundred seeds (kernels) are halved and bathed in stain
(colourless stain) before being set onto filter paper, the
embryo in seed (kernel) has turned red this means the barley
is viable (alive) but if it does not turn red then this means
the barley is dead and is no good for a maltser and therefore
load may be rejected (this is up to management decision).
We are looking for germinative capacity of around 96 - 98%
for germination (growing). We're looking for good quality.
SCREENING:
Screening checks are also carried out to check the quality
of the barley. One hundred grams of seeds (kernels) are put
onto the top tray of the machine and covered, the machine
is then switched on (machine is shaken) and left for 5 minutes.The
seeds (kernels) left on the 2.5 tray is the best quality barley;
the seeds left on the 2.2 tray is known as good barley and
anything left below is known as small barley siftings and
dust and goes on to make feeding (animal feed) pellets.
INSECTS:
We also check barley load for insects such as grain weevils
- we'll present a book showing types of unwanted insects and
what damage they can do to barley seeds. If any insects are
found in load the load is rejected immediately. We'll also
show
types of malting documents received with load as well as a
sampling device known as 'sampling sphere' which will take
samples from different levels in load, this is used manually
if sampling machine (referred to previously as Nodding Donkey)
is out of order.
We
will then proceed to see the process of barley to malt. The
only ingredients are Barley, Water and Air and there are three
stages: steeping, germination and kilning.
From this point, we will move on to the steep room. You will
be shown the control panel outside barley office which will
let us know which bins are full or being filled.
Steep
Room Here we soak barley to break dormancy and start
growth. We processs 44 tonnes of barley each day.
We have eight steeps which each holds 11 tonnes of barley.
You'll learn about the floor of steep - perforated panels
which allows water in for steeping and piping around - piping
which flows air into steep. These steeps are cleaned once
a week and chemical cleaned every 2nd week.
Water enters steep from the bottom and is filled up to line
on side of steep, barley enters from top to meet water, also
water is sprinkled into steep when barley is entering, this
keeps down dust. The steeping process takes two days. First
wet (steep) for 6 hours and then Air rest (drained) for 17
hours. Second wet for a further 6 hours and air rest for a
further 4 hours. You'll see the barley prior to casting showing
chitting.
After
steeping, it is then casted to saladin boxes which will then
take us to the second stage in the malting process. From here,
we'll move on to see the Saladin boxes and the germination
process.
GERMINATION:
We control the application of warmth to the growing barley
and to start to free the starch inside the barley seed (Kernel).
During germination, the developing plant releases enzymes
which will start to modify the starch. The complete conversion
of the starch into sugar is at the Distillery by milling the
malt and mashing it with hot water. Too much growth means
less sugar and there will be nothing left for the Distiller.
The germination process takes five days. This process is brought
to an end by kilning.
KILN: Kilinging involves stopping the growth
by removing moisture / humidity. This process allows us to
apply flavour in the form of peat smoke so that the whisky
made will have a distinct flavour depending on how much peat
smoke is applied. Kilning also preserves the malt.
Once
we leave the kiln, we'll proceed downstairs to see peat fire
and we'll then arrive back in the yard.
MILLING:
Malt passes through two sets of rollers each roller weighing
half a tonne each. It is crushed down to a powder we refer
to as grist. This grinding down must be done with care and
the rollers can be adjusted to give the required proportions
of husk, grits and flour in the grind to give maximum extraction
of sugars and to allow optimum drainage of the sweet wort
which is the sugary liquid we take from the mashing process.
Each grind is 10.6 tonnes which totals 160 tonnes a week.
MASHING:
Mashing involves taking the grist and our heated spring water
and then deposited into a mashtun. We take forward 10.8 tonnes
of grist and to this we add three infusions of water at varying
temperatures. The objective is to extract as much of the sugars
from the malt as we possibly can. We will take forward both
first and second waters “worts” to the fermentation
stage.
The
vessel is then filled from the top via the mashing machine,
water and grist deposited together – the first water
is heated to 64°C, second water to 78°C, and the third
water will be in the 90s. Both first and second waters will
provide enough sugar solution to take forward for fermentation.
The third water contains very little sugar so we reserve this
and use it to start off the next mashing cycle which for us
makes the best use of our resources.
The
mashing takes approx 8 hours. During this time, we extract
53,500 litres wort from the mashtun via the underback which
then passes through a plate heat exchanger which in turn preheats
the water for the second and third waters.
We
then cool the wort down to 19°C as it travels on to the
next stage called fermentation. Once completed, we have no
further use at the distillery for the residual grist, now
called draff which is sent to a dark grains plant where it
is processed into pellets and used for cattle feed.
FERMENTATION: We have a total of nine wooden washbacks
made from Oregon Pine. We fill each wash back with 53,500
litres of worts and to this, we add 8 x 25kg bags of yeast.
The
next step involves filling the wash back - combining yeast
and worts and let fermentation begin. The yeast loves sugar,
it consumes the sugary liquid, and once the oxygen in the
wort has been used up by the yeast the sugars are converted
into alcohol and Co2. The bubbles you will see is the carbon
dioxide gas being released.
This
part of the process takes in the region of 59 hours after
which we have a beer type liquid referred to as wash which
is in the region of 8-9% alcohol content.
The
wooden wash backs must be thoroughly cleaned after each fermentation
firstly with high pressure cold water jets then steam is pumped
into each vessel for an hour.
DISTILLATION:
For the distillation process, we will go to the still house
which is where we improve the quality of alcohol by boiling
in the copper pots. The Tamdhu Distiller has six copper pot
stills. Each distillery has their own individual size and
shape of still, which in turn will impart certain characteristics
to their new make spirit.
The
pots with the window in them are for the first distillation.
The window enables the
Stillman to view the boiling liquid and alter heat to prevent
the liquid boiling over.
We
pump 10,000 litres of wash into one of the large copper stills
which is then heated by a steam. The alcohol water vapour
passes through a shell and tube condenser, which is kept cool
using cold water from the burn, which runs past the distillery.
As distillation proceeds, the boiling temperature rises, the
amount of spirit vapour becomes smaller and the amounts of
water vapour greater. When there is only water left in the
liquid, the wash distillation is stopped. The residue in the
still is known as pot-ale which is despatched to the processing
plant in Rothes. This will be mixed with draff (residue from
the mashing) and used to process pellets for cattle feed.
The
safe here shows us the product from the wash distillation
(small safe) – around 25% alcohol and you can see that
it is quite clear. The distillate from the wash still - which
we refer to as low wines will be in the region of 25% alcohol.
The low wines are now transferred to spirit stills. This is
where 12,000 litres of low wines are charged to each still
in this area where we repeat the distillation process.
This
process concentrates the levels of alcohol and allows us to
select the middle part of the second distillation or the heart
of the run, which has the best quality alcohol between 75%
- 66%. It is this “middle-cut” we take forward
as spirit for maturation.
The
first and last fractions from the second distillation –
foreshots and feints are then distilled once again with the
low wines produced from the wash distillation.
These
low wines then go forward to the spirit distillation. The
receptacles in this safe (large safe) are for “spirit”
and “feints”, spirit being the heart or middle
of the run and feints the first and last part of the spirit
distillation and is on it way to the spirit stills again.
The handles on top of the spirit safe allow the flow of liquid
to be directed to either of the receiving jars. The new make
spirit we have produced will now be collected in the inter
spirit receiver before being transferred to the spirit receiver
warehouse vat.
FILLING
STORE: The spirit then will now head in two directions.
To the right hand side to tankers for new make spirit. Excellent
quality new spirit for the blending industry – Chivas,
Diageo and Ballantines are also customers. To the left hand
side for filling to our own casks for maturing here on Speyside.
NOTES: The maltings were modernised in 1949
/ 1950. The first malting came off the kiln in November of
1950. In 1966, the doubling of the malting capacity was achieved.