Whisky production Flashcards
What are the three main sources of flavour in whisky production
-The raw materials (Water, malted barley and yeast)
-The production process (Mashing, fermenting and distilling)
-Maturation
What kind of difference to flavour is water said to make
Little to none in comparison to the other factors if it is pure water
Where does water have the most impact in whisky production
During fermentation as its main influence is on the yield of the whisky
How may water impact the flavour of a whisky and during what process
Water can increase the yield of the whisky however the increased yield can make the resulting whisky less flavoursome
Water is preferable with what kind of pH
A high pH as soft water is a better solvent than hard water
What are the benefits of soft water during mashing
It is a better solvent and extracts more from the malt during mashing
Why might one be so inclined to believe that peaty water is better than just soft water
Peaty water contains carbon dioxide and acid producing bacteria from the peat which means its capacity to dissolve solubles in enhanced
what is the most important commonly regarded factor that is controlled by water
Purity as it is imperative that it be pure of organic and mineral impurity
How many scotch distilleries use distilled water and what are some of their methods of treating water
None, their means of treating water is to use UV light to kill any harmful bacteria such as ecoli
what two large factors influence the placement of a distillery regarding water
Its volume and temperature
how does water temperature affect the spirit in the cooling tubes after being distilled
Warmer water in the worm tubs mean that the vapours take longer to condense and liquify so there’s more contact with the copper so the spirit is lighter and purer
If a distiller wants a heavier more traditional spirit then why might the water be cooler in the worm tubs when cooling the copper coils
Colder water means that the vapours condense quicker and liquify faster so there’s less contact with the copper producing a heavier more ‘traditional’ spirit
In what months are most distilleries generally the most productive and which season do most distilleries time their ‘silent season’ for
Traditionally distilling is a winter activity and the silent seasons are usually when water levels are lower during July and August (the summer months)
How is barley graded
On a scale of 1 to 9 with only the top three grades being suitable for malting
Of barley grades 1 to 9 only the top three grades are suitable for malting and whisky producing, what percentage of barley is this?
around the top 20% of barley
how is quality defined in barley by Maltsters
-High starch content
-Low protein content
-Low nitrogen content
-High likely hood of germination
-easy to process
-well ripened
Why is it better suited for barley to have a high starch content
The starch is what is converted into sugar and then alcohol so higher starch yeilds higher alcohol
Why is it better suited for barley to have low protein content for whisky
higher protein would mean less starch so less protein means that there is more starch
Why is low nitrogen suited for barley used for whisky
high nitrogen is indicative of high protein which is not suited to barley as it means there is less starch
Why is it difficult for farmers to keep nitrogen low in their barley
nitrogen is the key ingredient of many fertilisers which are used to achieve a high yield, so farmers are forced to not over use fertilisers otherwise the barley becomes unsuitable for whisky
why is the high likely hood of germination an important factor of barley grown for whisky
Germination is a pre-requites for malting so it is essential that the barley is able to germinate
Why is it important that the barley is easy to process for whisky
It needs to be processed quite heavily in the mill and mash and not become glue-like as some varieties can
why is it important for whisky barley to be well-ripened, plump and dry
farmers are often told to leave the crop until its absolutely ripe and cannot wait any longer then leave it for 3 days because barley with moisture greater than 16 will go mouldy in storage (although this is now less of an issue with artificial drying)
why do distillers buy malt from scotland, the UK and abroad
To spread the risk of bad local harvests
what is the rough distribution of produced barley used for whisky
75% is from Scotland, 15% is from England and 10% is from abroad (France and Denmark)
what five regions is the UK divided into in terms of barley grown
Northwest (including northern Ireland and North Wales), Northeast, Central, Southwest and Southeast
until the 1950s which barley varieties dominated the market
Spatt archer and Plumage archer
What were some of the hybrids produced from Spatt and Plumage archer barley
Proctor, Pioneer, Maris otter and Golden promise
Which was the barley Maris Otter a hybrid of
Proctor and Pioneer
Which of the barley hybrids was the most important of the malting barleys in the 1970s
Maris otter
which barley variety introduced in 1966 was especially popular and why
-Golden promise
-It thrived on Upland farms
-gave higher yields
-it germinated quickly and evenly
How was the barley variety golden promise superseded
New varieties yielded increased alcohol levels and were less vulnerable to mildew and disease
In the 1980s what varieties of barley were introduced and what were they replace with by the 1990s
Halycon, Pipkin and Puffin were all introduced but later replaced by Optic and Chariot
What is currently the most popular variety of Barley
Laureate
Why has there been a slight increase in demand for golden promise [the barley variety] in recent years
its been in increased demand from smaller distilleries on account of the quality of the spirit even at the expense of yield.
what kind of differences are offered by the different varieties of Barley used in whisky production
little as any potential flavour differences are likely worked over due to intense processing and alcohol. However spirits made with Golden promise can be more oily and richer.
what is the modern day potential fear surrounding varieties of Barley
There is concern that new varieties sacrifice flavour to alcohol yield and resistance to diseases as well as that they change to quickly as new hybrids are developed.
What is yeast and how many cells of it are in a gram
It is a fungi micro-organism, one gram of which has around 10 million cells
What are the main products of yeast breaking down sugars
Carbon dioxide and alcohol
what is the typical pitch in terms of yeast percentage to the volume of malt mashed
Around 2.2%
Using the normal amount of yeast, how much yeast would your typical mash of eight tonnes require
175kg
How long does it take for a visual reaction between the yeast and the mash take to occur
a couple of hours
how long could fermentation go on for and what solution is produced and what is it called
It can go on for over 50 hours and it produces a saccharine malty solution called wash
What is Wash produced as during fermentation
Wash is a saccharine malty solution which foams a lot
how is the foam broken inside the washback to prevent it overflowing or building up pressure and how has this changed in the past
In the past were the yeast was less predictable people were employed to fight back the foam with heather flails or brooms. Now however mechanical switchers are used to break the foam
On occasion what a be added to help break the foam
Unperfumed liquid soap
what sort of yeast do distillers use today
cultured yeast that is grown from a single cell and it is either liquid, dried or most commonly solid
how does the yeast contribute to flavour
The yeast produces alcohol and congeners which include a range of esters, aldehydes, acids and other higher alcohols that all contribute to flavour
What do congeners from yeast contribute to the flavour
They produce a range of esters, aldehydes, acids and other higher alcohols
what two parts make up the barley (which is a seed)
An embryo (The part that grows into a new plant) and the endosperm (which is the store of starch that feeds the young plant)
during germination what enzymes does the barley predominantly produce and what’s its purpose
-Cytase which breaks down the cell wall and enables the starch accessibility for growth
-Amylase (also called diastase) which converts starch into a soluble form dextrin
What is dextrin (starches soluble form) converted into by amylase during mashing
Maltose a soluble sugar
what is malting in simple terms
It is effectively controlled germination
what do maltsters try to achieve during the germination process i.e what stage do they try to get to and how do they end the germination at that stage
They try to get it to a stage were the cell walls have been broken down but the starch has not yet been used by the growing plant. They stop germination at this stage by drying the ‘green malt’ in a kiln
What is green malt and why is it put in a kiln
Green malt is malt that has been going through germination and it is put in a kiln to dry it and stop germination at the desired stage
What moisture does dry barley have
12%
what moisture level does barley need to have in order for enzymes to be activated
46%
After the barley is cleaned how is its moisture level raised from around 12% to 46% after kilning
It is immersed in fresh water 3 times and this lasts for two to three days
How is the time that barley needs to remain immersed under water during steeping affected and changed
-Nitrogen levels
-temperature of the water
-ambient temperature
-Size of the grains
-The grains capacity for absorption
How is clumping during steeping avoided
The barley is constantly aerated whilst underwater which ensures equal uptake of water as well
what can a maltster do if they oversteep of understeep the grain
-If they oversteep it and it absorbs to much water it can be dried out by a tumble drying process
-if he under steeps it he can spray it however this can lead to uneven water uptake
how is regular germinating carried out i.e in the traditional sense
The barley is spread out across a concrete floor (Floor malting) to a depth of around 30cm
If floor malting is carried out why does it need to be turned with wooden shovels
the grains of barley sprout little rootlets which generate heat especially close to the floor so they must be turned to keep temperatures even and prevent the roots tangling
What does ‘turning the piece’ refer to in terms germinating barley
this is the process of turning barley to ensure even temperatures and prevent the roots from tangling
How long does floor malting usually go on for
it is usually about a week or less in hot weather
at what rate during germination does the barley loose moisture
The moisture is lost at around 0.5% per day
what eventually happens to the rootlets during germination and how do maltsters gauge if this has taken place and whether germination has gone on for the right length of time
The rootlets wither and die and maltsters will taste the grain to test its sweetness as well as rub it to access its texture. If it is chalky and smooth it is ready, if it lumps then it is not.
What does the term ‘modification’ refer to in terms of germination
Modification refers to the rootling’s of the barley withering and dying and the green malt becoming mealy which is tested by its sweetness and texture
how can having your own maltings be beneficial and what are the downsides of this
it allows for greater control of the flavours sought, its more natural and it doesn’t force germination. However it is slower and requires suitable space for doing so.
Which distilleries produce 10-20% of their malt requirement with their own floor maltings and which distilleries meet 100% of their malt requirement via their own floor maltings
Bowmore, Laphroaig, Balvenie and highland park all produce 10-20% of their own barley and floor malt it.
Springbank and Glen Ord produce 100% of their needs.
what are the main problems with floor malting that mean it is done less in distilleries now compared to what it used to
It imposes a limit on the amount of malt that can be made at a time and it is labour intensive.
What have most distilleries replace floor malting with
pneumatic malting systems in large scale centralised maltings owned usually by individual companies
what are the two pneumatic systems for germination that are used today
Rotary drums and kilning vessels (SGKVs)
How do rotary drums work as a means of germinating barley as an alternative to floor malting
Its charged with damp grain from steeps (From 9 to 50 tonnes of grain), it is then turned by gravity around 9 times a day. As it rotates the humidity and temperature are controlled by internal sprays and blowing air
When were SGKVs first created (Kilns for germination)
Late 1970s
As a brief overview how does Kilning work
The green malt is spread over a metal perforated floor with a furnace below that heats it up to dry it
What are the two types of kilning and how do both work
-Directly fired, which is were the gasses of combustion pass through the malt bed
-Indirectly fired, where the air is heated by oil fired burners or steam heated radiators
what kind of roofs do Kilns have that have been used since the 19th century
Pagoda roofs which cap the tapering roofs which help to draw out the heat
What is the first stage of the kilning process
the free drying phase which evaporates any moisture on the surface of the green malt
What temperature is the warm air used for the first stage of kiling (to evaporate moisture on the surface of the green malt)
60 to 65 degrees Celsius
what stage of kilning is peat used if it is going to be used
The first stage, the free drying phase
What is the maximum temperature that can be used for the first stage of kilning if peat is used and why is this
60 degrees Celsius because any higher and the phenols that lend the whisky its smoky characteristic are destroyed. The peat also adheres to the barley husks only when they are still damp
How does the temperature of the first stage of kilning affect the level of peatiness if peat is used
The lower the temperature the greater the peatiness
After the first stage of kiling (The free drying phase) what is the second phase
The forced drying stage during the which the temperature is raised to 70-75 degrees Celsius and the airflow is reduced.
By the end of the Forced drying phase of kilning what is the level of malt moisture
Around 5%
What is the third and final stage of Kilning and what does it achieve
The final stage is the cooling phase were the temperature is lowered to around 30 degrees Celsius to prevent further curing of the malt.
How long does the whole Kiling process usually take and what affects this length of time
It takes between 20 and 48 hours depending on the type of kiling process being used, the size of the kiln and the amount of malt
What is peat
It is acidic decayed vegetation made from bog plants such as sphagnum moss, heather, sedges and grasses.
what are the necessary conditions for a peat bogs development
there must be a cold atmosphere, high rainfall , poor soil drainage and/ or aeration. The waterlogged soil is unable to break down the vegetation so a thickening layer of peat begins to develop.
what happens to the peat once it is cut
It is laid out on the heather for around a fortnite surrounding the peat bog then it is stacked into small pyramids called cas bhic to throughly dry for a year
what is the term used to explain how and why peat varies from place to place
Its palaeobotany
How may a lowland peat vary from and compare to peat bogs closer to the sea
Lowland peat bogs have more vegtable matter, are looser and brun more rapidly giving off more dust whereas peat bogs close to the sea may be saturated with sea spray and may eaven contain seaweed from winter storms etc.
How is peat in Orkney graded
its got three grades, the top layer is ‘fog’ which is Rooty, the second layer is ‘yarphie’ which is small roots then the bottom layer is ‘moss’ which is the darkest layer that’s best for heat but not smoke
what are the three broad categories of peating
-lightly peated (1-5PPM)
-Medium peated (10-20PPM)
-Heavily peated (30-50PPM)
with regards to mashing articulated trucks arrive and typically bearing how many tonnes of malt
5,000 tonnes
malt is ‘dressed’ what does this term mean
It means that the malt has been passed over a reverberating wire mesh that removes clum
In terms of dressing malt before mashing what does ‘clum’ refer to
Clum is the withered shoots and rootlets produced during malting
What are the three key processes that make up malting
Steeping, germinating and kilning
from the malting process what are the main waste products used to make cattle feed
The ‘culms’ and other waste products
at the distillery the moisture levels of barley is tested, what is the maximum allowed moisture
12%
What three important factors regarding the malt is tested before mashing in the distillery
Moisture it must be below 12%
Viability for germination it must be 99% viable
Insect infestation
What process does the malt undergo when at the distillery before mashing
It goes through screening to remove any dust, stones and small grains
when needed the malt is transferred into the mill hopper then into the mill which has two sets of rollers. What do the two rollers do
One cracks the husks and the other grinds the malt
When grinding malt in a mill what are the percentages of flour, husk and grist
10% flour, 20% husk and 70% grist
What are the consequences to the proportions of flour, husk and grist not being correct
if it is too fine then the mash tun will not drain quickly enough.
If it is too coarse the liquor will drain too fast and maximum extraction will not occur
What is the grist mixed with in the mash tun to extract the maximum amount of soluble starch
Hot water
which Enzyme is also reactivated in the mash tun that would have become inactive during the other processes
Amylase which completes the conversion of starch into maltose
What are the key features of a mash tun
They are large circular vessels often with copper lids to conserve heat usually made from stainless steel or cast iron with a perforate floor through which the worts can drain
during the stage of mashing what is the liquid that is drained through the bottom called
Worts
How greatly do mashtuns vary in size and what else do they contain to aid in the process of mashing
They can vary between 1 tonne and 15 tonnes, they also have a rake on the inside which periodically stirs the mash