The 'Gazette'

Understanding distillation

Distillation is the key stage in the production of spirits. It concentrates the aromas by extracting and selecting volatile compounds from the fermented wort. During the distillation of the future whisky, water and ethanol vehicle a large number of aromatic compounds. This article looks at some of a few fundamental elements of the distillation process.

What is distillation?

Distillation is above all a technique widely used in the chemistry field. It is a separation and purification process, based on heating and then cooling a mixture of liquid substances with different boiling temperatures. In simple terms, the liquid to be purified is brought to boiling point: with the heat, the substances successively vaporise before being condensed with the help
of a refrigerant. The result is a liquid concentrated in alcohol and aromas called the distillate.

Comprendre la distillation dans le whisky

Distillation, it’s all about boiling temperature

Concerning whisky, the wash – a liquid mainly made up of water and alcohol – is heated. At atmospheric pressure, the boiling point of ethanol is 78°C whereas water boils at 100°C. When the wash is heated above 78°C (but below 100°C), the alcohol starts to boil and vapours rich in alcohol are released. The alcohol will then gradually carry away the volatile molecules, which will condense back into liquid form. The idea is to work with this volatile fraction to isolate the most interesting aromatic compounds that will then give the distillate the typicity we are looking for.

The different types of distillation used in whisky production

There are two main distillation styles:

Continuous column distillation: a single uninterrupted distillation that requires a specific type of still: the column still or “Coffey Still”. This still consists of one or more columns containing several plates placed at specific intervals. Whisky produced from a column still is generally lighter.

Alambic à colonne et alambic charentais

Batch distillation: this is the distillation method traditionally used for Cognac, but also for Scottish Single Malts. This distillation technique produces spirits with intense and complex aromas, with finesse and a good structure.

Maison Lineti uses, to produce its Single Malt, batch distillation. We’ll go into more detail about this style of distillation in the next article.

Would you like to find out more about distillation?

Broom, D. L’atlas Mondial du whisky (2015). Eds Flammarion
Piggott, J. R., & Conner, J. M. (1995). Whiskies. In Fermented Beverage Production (pp. 247-274). Boston, MA:Springer US
Swan, J. S., & Burtles, S. M. (1978). V The development of flavour in potable spirits. Chemical Society Reviews, 7(2), 201-211
Alcarde, A. R., Souza, P. A. D., & Belluco, A. E. D. S. (2011). Chemical profile of sugarcane spirits produced by double distillation methodologies in rectifying still. Food Science and Technology, 31(2), 355-360
Arrieta-Garay, Y., García-Llobodanin, L., Pérez-Correa, J. R., López-Vázquez, C., Orriols, I., & López, F. (2013). Aromatically enhanced pear distillates from blanquilla and conference varieties using a packed column. Journal of agricultural and food chemistry, 61(20), 4936-4942
García Llobodanin, L., Roca, J., López, J. R., Pérez Correa, J. R., & López, F. (2011). The lack of reproducibility of different distillation techniques and its impact on pear spirit composition. International journal of food science & technology, 46(9), 1956-1963

Distillation | November 2024 | Dr. Magali Picard

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