Amelioration of smoke derived taint in wine by membrane filtration and solid phase absorption

Abstract

This study was in response to a call to find a solution to the problem of smoke taints caused by bushfires. Aromas described as smoky, burnt and dirty plus reports of a lingering ash sensation had caused concern about consumer reactions and financial impacts.

Summary

A collaboration funded by Wine Australia and involving The Australian Wine Research Institute and, Curtin University of Technology, with in-kind support from membrane manufacturer Memstar Pty Ltd, considered a possible solution could be combined membrane filtration and solid phase adsorption. This was based on the molecular weights of the most offending compounds associated with smoke taint, plus other parameters. Evaluation of the capacity of this technique included measurement of wine constituents, both desirable and undesirable, which could permeate the membrane filter and be subsequently removed by adsorption. Another task was to assess commercial feasibility of such a process. Commercial wines from two wineries in bushfire-affected North East Victoria were used in the study (2007 vintages of Sauvignon Blanc and Pinot Noir). Chemical composition and sensory attributes were compared before and after treatment

Concentrations of the smoke-derived volatile phenols guaiacol and 4-methylguaiacol decreased with the treatment and acceptability of wines was agreed by tasting panels. There was no significant effect on wine compositional attributes such as pH, titratable acidity, sugar, alcohol or colour.

For the wine industry this means it has a potential amelioration technique to use following vineyard exposure to smoke. At a cost of $60 per kL it would be a viable option to use depending on value of the wine.