The lack of reproducibility of different distillation techniques and its impact on pear spirit composition. http://dx.doi.org/10.1111/j.1365-2621.2011.02707.x

Abstract

We analysed the impact of operation variability on the composition of pear spirits obtained with a Charentais alembic and a packed distillation column. Lack of reproducibility significantly affected the spirits’ compositions, with batch distillation columns more difficult to operate reproducibly vs. traditional alembics.
The composition of column distilled spirits differed more in esters, such as ethyl octanoate, ethyl decanoate and ethyl palmitate. In turn, alembic spirit compositions differed more in acetaldehyde and acetal. Moreover, column distilled spirits contained four times more esters, 20% more higher alcohols, 40% less acetaldehyde and 10% less methanol than alembic spirits. Spirits distilled with a rectification column were more concentrated in ethanol than alembic distilled spirits, although both distillation systems recovered the same amount of ethanol in the heart fraction.