Fruit Brandy Production by Batch Column Distillation With Reflux

Abstract

The relationship between the operating parameters of batch fruit spirits column stills with reflux and the congener (trace compounds that provide flavors and aromas) concentrations in resulting fruit spirits has not been widely studied. Congener concentrations were determined in three different collection fractions, or “cuts,” during batch distillation. Acetaldehyde and ethyl acetate were found in higher concentrations in the head cut, first overhead fraction, of the distillation and have lower boiling points relative to ethanol. 1‐Propanol and isoamyl alcohol (isopentanol) were present in higher concentrations in the tail cut, third or final fraction, of the distillation and have boiling points that are higher than ethanol. Methanol has a unique concentration profile as it has higher concentrations in both the head and tail cuts, but a lower concentration in the heart cut, the middle fraction which is the desired product of the distillation. Methanol was of particular interest because the distillate must adhere to governmental regulations that limit its concentration in the product. Operating‐condition parameters that were studied include the number of trays used in the distillation as well as the use of a “catalytic converter,” a high surface, copper‐packing material thought to catalyze formation of cyanide‐containing compounds allowing them to be separated from the distillate. The effect of the number of trays used in a distillation on the concentration of ethanol and the congeners, methanol, acetaldehyde, ethyl acetate, 1‐propanol and isoamyl alcohol in the final distilled spirits product is presented. An additional result of acetaldehyde production at the copper surface of the catalytic converter was also discovered in the analysis of the data.

Distillation Techniques in the Fruit Spirits Production

“…When distilling mixture has higher concentration of alcohol (higher than 40% (v/v) [44]), higher alcohol will distill following the boiling points, and their concentration will increase as the distillation process progresses. This explains why distillates in the column showed higher concentration of higher alcohol in the tail [21] and distillates in pot still (Figure 6) showed higher concentration of higher alcohol in the head [18,40].…”

“…It appears mainly in the head fractions when distillation column was used [21]. Results of Cortes et al [32] showed the concentration of the methanol was seven times higher in the case of industrial distillation (means higher concentrates and cleanses of ethanol) than the concentration of methanol in the distillates obtained by simple pot still.…”

“…Claus and Berglund [21] are observed that distillates produced in the alembic pot still are usually stored in wood for many years (e.g. Cognac and Whisky), whereas the distillates produced in the distillation column are stored in the glass and consumed as clear spirits.…”

“…Such, Ribéreau-Gayon [35], considered the methanol imparts a cooked cabbage odour in spirits, with a threshold of 1200 mg/l. Claus and Berglund [21] wrote that methanol is considered to be a positive lavour constituent in distilled spirits. Nevertheless, most researchers say methanol is colourless volatile compounds with a mild or bland odour and does not afect the lavour of distillates [10,32,36,37].…”

“…Batch distillation column style requires just one distillation to achieve high alcohol degree [21,22]. In single-stage distillation, also these fractions are separated: the head, heart and tail.…”