alcohol distillation

Whiskey, gin, or vodka distilling starts with fermented alcohol which starts its life as a wash. Although many spirits share similar ingredients and processes, each requires specific alcoholic distillation techniques in order to achieve signature flavors. Distillation requires selecting congeners (aldehydes, acids, esters) carefully in order to extract these signature flavors without eliminating those you don’t want.

After fermentation is complete, wash is taken to a still where it’s heated to turn alcohol in to vapor form. From there it travels upwards through its Swan Neck/Lyne Arm into a condenser where it returns back into liquid form – this ratio determines both product purity and energy requirements. It’s referred to as the Reflux Ratio.

Distillation continues until a desired proof is reached, at which point it’s time for blending, an often artful process that depends on experience, scent and taste, intuition and experience. Each distillery decides when and how much of the distillate should be cut back depending on taste, experience and intuition of their distiller – this decision being called the art of blending – which also determines when cuts should be made on run portions to be kept and which can be let go as part of this art form. Depending on what type of still it uses timing will do this, while for column stills position will do just this job.”

Distillation is a widely-used separation technique which uses heat to vaporise liquid mixtures before condensing them back down, isolating their individual components by applying heat. Volatile components are separated from non-volatile ones through this process; typically the volatile fraction is known as heads and the rest hearts and tails (head being highest volume component and tail as lowest). Distillate runs can contain one or both heads or hearts or tails containing low boiling point compounds with undesirable impurities which must be eliminated prior to creating their final spirit product.

Distillation operates under the assumption that all components in a liquid at a given temperature have their own individual boiling point, and can therefore be separated based on these. Unfortunately, however, liquid mixtures often comprise different azeotropes with differing boiling points which form bands overlapping one another; to create ultra-pure products more chemical separation processes must be used in addition to distillation to remove impurities from distillate.

There are various techniques for breaking an azeotrope and producing pure distillates, including increasing or decreasing pressure, adding or subtracting components from its composition, or physically separating it.

Hybrid processes that use solvent extraction and absorption require considerable amounts of energy to reach high temperatures necessary for volatiles to vaporise from compounds, as well as maintaining suitable pressure in these processes. Achieveing this may present additional challenges for plants.