2 - Factors Affecting the Style and Quality of Spirits Flashcards
From what can spirits be made?
Anything of agricultural origin that contains carbohydrates
List the four key stages common to production of all spirits
Processing the raw material
Alcoholic fermentation
Distillation
Post distillation operations
How does ‘overproof’ relate to ‘proof’?
It’s from a separate, antiquated system
Summarise distillation
Takes place in a still
Alcoholic liquid is heated
The liquid boils and turns into vapours
The vapours are condensed and collected as new liquid
What is the aim of distillation?
To select and concentrate individual parts of the alcoholic liquid and leave others behind
What is a common level of concentration taking place in distillation
10% abv to 75% abv
How high can distillation take a spirit in abv?
96%
Lower abv spirits will have…while higher abv spirits will have…
Greater aroma intensity and complexity
Lower aroma intensity and complexity
What is a fraction?
Any one of hundreds of individual chemicals that make up an alcoholic liquid
What is a congener?
A fraction that has an aroma detectable by the human nose
What is the aim of most post-distillation operations?
To ensure that a spirit is sold with the correct colour, aroma, sweetness and alcoholic strength
What’s the aim of processing the raw material?
To create a sugary liquid
How are sugars stored in the raw materials for spirits?
Fermentable sugars
Complex carbohydrates
In what materials are the sugars readily fermentable?
Grapes and sugar cane
Give two examples of raw materials in which the sugars are complex
Grains and agave
Besides sugars, what else do raw materials offer? Give examples
Aromas
Blue agave - earthy, peppery aromas
In which spirit are all congeners removed during production?
Vodka
What must a distiller use if they want to produce high quality spirits?
High quality raw materials
Why are high quality materials important?
Small defects can be concentrated by distilation
What is the principal aim of fermentation?
To create an alcoholic liquid called ethanol
What is the common range of abv created by fermentation?
8-10%
Besides the typical by-products of fermentation, what else can be created?
Many congeners/fractions
What are the two groups of congeners with which we’re concerned?
Other alcohols
Esters
What are the main other alcohols produced besides ethanol?
Methanol
Fusel alcohols
What are the advantages and disadvantages of the other alcohols?
They can add complexity in small amounts
The aromas can become unattractive
Describe esters
They have an attractive fruity smell
When are the greatest number of congeners produced?
During fermentation
How might a distiller reliably produce the right amount and type of congeners for their spirit?
By using specific, bought-in yeasts
Where do ambient yeast come from?
In and around the distillery
What’s the argument in favour of using ambient yeast?
They argue that the fermentations can be just as consistent and the final product is more complex
Give notable examples of producers who use ambient yeast
Rum producers
Producers of agave spirits
What’s the aim of distillation?
To concentrate and select ethanol and some of the congeners present in a fermented alcoholic liquid
What characteristics are shared by all newly distilled spirits?
Water white
Colourless
Dry
Summarise the four stages of distillation
Liquid made of ethanol and water
Liquid heated
The more volatile ethanol evaporates at a cooler temperature
The vapour is collected and condensed back to a liquid that’s higher in abv than the original liquid
What is present in steam?
Water droplets
Water in gas form
What is reflux?
The interaction between vapour and gas from an alcoholic liquid
Explain reflux
When gas and vapour interact, gas and vapour reforms. As ethanol evaporates more easily, reflux makes the gas more alcoholic
What is rectification?
The rise in alcohol as a result of reflux
Besides abv, what else is affected by rectification?
Aroma intensity
Nearly all pot stills are made from…
Copper
Why is copper often used in pot stills
It’s easy to shape
It’s a good heat conductor
What’s the swan neck?
It’s the section of tubing between the pot and the still head
What’s the Lyne Arm?
The tubing that links the still head to the condenser
What does the Condenser do?
Converts the vapours back to liquid
How are most modern stills heated?
Steam
How might steam be used to heat a still?
Internal coils
External jacket
What’s the traditional method for heating a still?
A gas burner
What’s the most common type of condenser?
Shell and tube condenser
How does a shell and tube condenser work?
The vapour enters the top and comes into contact with pipes that contain a coolant
The cold tubes cause the vapours to condense back into a liquid
The liquid flows out the bottom of the condenser
What’s the other type of condenser?
Worm tub condenser
…is a batch process
Pot still distillation
Describe spirits from pot stills
Low level of rectification
Characterful
Medium to pronounced aroma intensity
How many times must a fermented alcoholic liquid be distilled to produce a spirit?
At least twice