FRUIT BRANDY PRODUCTION BY BATCH COLUMN DISTILLATION WITH REFLUX

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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.