title: Changes in Wine Ethanol Content Due to Evaporation from Wine Glasses and Implications for Sensory Analysis.
abstract: The relative proportion of water and ethanol present in alcoholic beverages can significantly influence the perception of wine sensory attributes. This study therefore investigated changes in wine ethanol concentration due to evaporation from wine glasses. The ethanol content of commercial wines exposed to ambient conditions while in wine glasses was monitored over time. No change in wine ethanol content was observed where glasses were covered with plastic lids, but where glasses were not covered, evaporation had a significant impact on wine ethanol content, with losses from 0.9 to 1.9% alcohol by volume observed for wines that received direct exposure to airflow for 2 h. Evaporation also resulted in decreases in the concentration of some fermentation volatiles (determined by gas chromatography-mass spectrometry) and a perceptible change in wine aroma. The rate of ethanol loss was strongly influenced by exposure to airflow (i.e., from the laboratory air-conditioning unit), together with certain glass shape and wine parameters; glass headspace in particular. This is the first study to demonstrate the significant potential for ethanol evaporation from wine in wine glasses. Research findings have important implications for the technical evaluation of wine sensory properties; in particular, informal sensory trials and wine show judging, where the use of covers on wine glasses is not standard practice.
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide , PMB 1, Glen Osmond, South Australia 5064, Australia.|Australian Research Council Training Centre for Innovative Wine Production , PMB 1, Glen Osmond, South Australia 5064, Australia.|Memstar Pty. Ltd. , 712 Research Road, Nuriootpa South Australia 5355, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Wollan
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide , PMB 1, Glen Osmond, South Australia 5064, Australia.|Australian Research Council Training Centre for Innovative Wine Production , PMB 1, Glen Osmond, South Australia 5064, Australia.
authors.forename: Duc-Truc
authors.initials: DT
authors.lastname: Pham
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide , PMB 1, Glen Osmond, South Australia 5064, Australia.|Australian Research Council Training Centre for Innovative Wine Production , PMB 1, Glen Osmond, South Australia 5064, Australia.
authors.forename: Kerry Leigh
authors.initials: KL
authors.lastname: Wilkinson
mesh_terms: D000431:Ethanol / Q000032:analysis / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D009812:Odorants; D012903:Smell; D055549:Volatile Organic Compounds / Q000032:analysis; D014920:Wine / Q000032:analysis
chemical_list: D055549:Volatile Organic Compounds; D000431:Ethanol
keywords: alcohol; aroma; ethanol; evaporation; sensory evaluation; wine; wine glasses