Distillation is used for numerous applications, including the distillation of essential oils and spirits. Our stills are perfectly suitable for these applications nevertheless certain precautions should be taken to avoid personal injury as a result of negligence or the continuous consumption of poor results.
Distillation is a basic chemical science which involves the separation of a chemical substance into its different components based on difference in the boiling point of each fraction. This is done by heating a mixture in an alembic pot so the fractions that make up the mixture begin to evaporate, these are conducted via a connecting arm or swan neck into a condenser where they are chilled and revert to their liquid state.
Ethanol alcohol evaporates at 78.3ºC at sea level and water at 100ºC but a mixture of the two components will evaporate between 78.3ºC and 100ºC depending on the ratio of ethanol alcohol and water.
The more volatile components or those fractions with a lower boiling point will tend to evaporate first so the resultant vapours will be more enriched with those components with a lower boiling point.
A fermented batch may be composed of ethanol, other higher alcohols such as methanol also acetone, various esters, water and furfurals. The more volatile components such as acetone, methanol and the various esters are undesirable.
It is common practice to throw away the first portion of the distillate, this way you will get rid of the methanol and other volatiles. Separate and discard the first 50ml if distilling a 25 L wash or mash in a reflux still or 100ml per 20L wash from the rest of the distillate if using a traditional alembic, these fractions are known as foreshots or heads and are distilled first.
The result of any distillation is divided into three separate parts (or fractyions) in the following order: heads, hearts and tails.
The percentage at which to do the cut may depend on the flavour profile you may want to obtain and the kind of wash distilled. As a rule for fruit mashes the cut off point for tails may be 25% alcohol and for grain washes 18%, this is not a hard and fast rule and the distiller has to toggle with these values to obtain the desired flavour profile.
Most distillates are double distilled to further purify the distillation results and raise the alcohol percentage. A second distillation may also concentrate the flavour further. The cut off point for a second distillation in a fruit mash may be as low as 60%. For grain washes a cut off point may be established at 58% or higher.