Tingting Shi, Renata Ristic, Cassandra Collins, and Kerry Wilkinson*
*The University of Adelaide, PMB 1, Glen Osmond, 5064, Australia 
(kerry.wilkinson@adelaide.edu.au)

Activated carbon has proven to be a useful adsorbent for amelioration of smoke-tainted wine, enabling removal of smoke-derived volatile phenols (guaiacols, cresols, and syringols) thought to be responsible for objectionable smoky, medicinal, and ashy characters. Proof-of-concept studies recently demonstrated the potential of activated carbon fabric to mitigate smoke contamination of grapes in the vineyard. Postharvest smoke exposure of Mataro grapes resulted in wine with elevated volatile phenol concentrations (i.e., up to 21 µg/L). However, the composition of wine made from grapes that were enclosed in activated carbon fabric prior to smoke exposure was comparable to that of control wine; only 1 µg/L differences in guaiacol, o- and m-cresol, and/or syringol concentrations were observed. Furthermore, while wine made with smoke-exposed grapes exhibited diminished fruit intensity and pronounced smoke attributes, the sensory profiles of wines corresponding to activated carbon fabric treatments could not be differentiated from that of control wine. A small but significant loss of color was observed and attributed to adsorption of anthocyanins by activated carbon fibers that adhered to grape bunches and were therefore present during fermentation. The application of activated carbon fabric to individual bunches of grapes is clearly not feasible in commercial vineyards, therefore, field trials involving the application of activated carbon fabric to the fruit zone of grapevines were undertaken. The (black) activated carbon fabric caused premature senescence of covered leaves, but did not meaningfully affect berry ripening. Wine compositional analysis again confirmed that fruit enclosed in activated carbon fabric was protected from smoke contamination, evidenced by significantly lower volatile phenol concentrations. Several shortcomings must be addressed before this mitigation strategy can be implemented by the industry for use in commercial vineyards, but results are highly promising.

Funding Support: Wine Australia, The University of Adelaide, Peter Michael winery