The University of Valladolid team developed a method, detailed in the report Pervaporation methodology for improving alcohol-free beer quality through aroma recovery, to extract three aromatic compounds from a 5.5% alcohol by volume (ABV) beer and a 6.5% ABV beer.
Ethyl acetate, isoamyl acetate, and isobutyl alcohol were recovered from the beer samples using pervaporation.
Using a semi-permeable membrane the University of Valladolid team to remove the the alcohol from 5.5% and 6.5% ABV beers.
The recovered vaporous permeate was then condensed and incorporated into the low-alcohol (less than 1% ABV) and alcohol-free beers (less than 0.1% ABV).
“Sensory analysis confirmed that this was accomplished,” said the study, which was published in the Journal of Food Engineering earlier this week.
A panel of tasters were drafted in to assess the enriched low-alcohol and alcohol-free beers.
"...90% of taster preferred enriched low-alcohol beer instead of low-alcohol beer and 80% of tasters preferred enriched alcohol-free beer instead of alcohol-free beer," said the study.
"We have demonstrated that pervaporation can be used to recover aroma compounds in beer. The addition of these aroma compounds to more or less de-alcoholized beer enriches their flavour."
"This increased their appreciation and could be used to meet the quality standards required by the market."
Source: The Journal of Food Engineering 10.1016/j.jfoodeng.2014.02.014
Title: Pervaporation methodology for improving alcohol-free beer quality through aroma recovery.
Authors: A del Olmo, C Blanco, L Palacio, P Pradanos, A Hernandez.