Raw materials Flashcards
What type of barley can be malted and used for whisky production?
Technically, any. However, specially bred varieties with appropriate agronomic (how it grows on a farm) and malting characteristics are grown for the distilling industry.
What functions are barleys bred for?
Barleys are bred for various functions, but they must be rich in starch and enzyme potential.
Starch is crucial for alcohol yield.
Enzymes are required to break the starch down into sugars so that the yeast can metabolise it into alcohol during fermentation. All the enzymes required during the malt whisky production process must come from the malted barley.
Where can barley be grown?
Barley can be grown in any geographical area but the majority of barley used in Scotland is grown in the UK. Even specially bred barleys are subject, in any year, to the vagaries of the weather. Many are rejected at harvest time as unsuitable.
What must be done with the barley prior to use in the distillery?
Suitable barley must be dried and then malted. These days, this typically happens at dedicated malting plants.
A small number of distilleries still use tradititional floor maltings on site for a proportion of their requirements. (Balvenie, Bowmore, Highland Park and Springbank for example).
Which distillery is the only one in Scotland to use traditional floor maltings for all of their barley?
Springbank.
Where is all of the water used in the production process of Scotch whisky derived from?
Rain or snow, meaning it is fresh water.
A plentiful supply of water is required in the whisky making process, which is why historically whisky distilleries were always located near a burn or loch.
A lot of the water used in the distillation process will have fallen as rain over 100 years ago.
What are the 4 main purposes water is used for in the Scotch whisky production process?
- Mashing water: Hot water is added to the grist to produce the mash.
- Cooling water: Plentiful cool water is required to condense the alcohol vapour back into liquid during distillation.
- Dilution water: Pure water is added to the New Make Spirit (NMS) to reduce to filling strength for maturation.
- Washing waters: As the production equipment is cleaned, it generates washing waters that are required to be treated as effluent.
When and how is water treated prior to use?
Water for distilling is generally not treated prior to use as it will be coming from a pure and fresh source. Othere than for reduction, water for distilling is exempt from the water potability regulations, since it will become subject to the distillation process.
The water can be filtered to remove debris and is sometimes treated with UV light to deal with any microbial contamination.
What is yeast?
A single-celled organism which feeds on sugar, producing alcohol, carbon dioxide, heat and flavour compounds in return.
What species of yeast is used in the production of whisky
Saccharomyces cerevisiae.
It typically has a 10 micron cell diameter and 1,000,000,000 cells per gram.
How does fermentation occur?
Under anaerobic conditions (in absence of oxygen), yeast metabolises sugar, producting alcohol as a by-product.
What is the difference betweeen “ethanol” and “alcohol”?
These words are used interchangably.
Ethanol is a type of alcohol made during fermentation. Alcohol often refers to whisky and other drinks in general.
Yeast is now produced in specialist plants and delivered in what ways?
- Slurry
- Cake (pressed)
- Dried yeast
Slurry has now become the routine way to have the yeast delivered to the distillery.
What is peat?
Peat is essentially decomposing plant material that is produced in a wet environment in the absence of oxygen. It can be dug up and dried, becoming a fuel that can be burned.
Although not technically a raw material, peat can be used to add flavour to the malt duing the Scotch whisky production process.
What aromas does peat typically impart in the final spirit?
Medicinal or smoky aromas.
