Ioan Pavel Gitsov, Rosemary Veghte and Tom Collins*
*Washington State University, 359 University Dr., Richland, WA 99352 (tom.collins@wsu.edu)

Smoke exposure to grapes prior to vinification can lead to the presence of smoke-related volatile phenols and associated glycosides. These compounds provide negative sensory attributes to the wines, including ashy, medicinal, and smoky aromas and aftertastes. A method to alleviate this taint prior to bottling is needed to mitigate the negative impacts of smoke exposure in finished wines. Smoke-affected wines from the ongoing smoke taint project in the Collins lab and affected wines from commercial wineries were treated using a small-scale reverse osmosis (RO) filtration system, in which the smoke taint compounds migrated into a permeate stream. The permeate stream was then passed through carbon filter beds to remove the smoke-taint compounds. The composition of the permeate and retentate streams were analyzed using gas chromatography-mass spectrometry (GC-MS) and ultra-high pressure liquid chromatography-quadrupole time of flight-mass spectrometry (UHPLC-QTOF-MS). Principal component analysis of compositional data collected during an RO time-course study found separation between samples from the permeate and the treated wine. In the treated wine, several smoke taint compounds showed a decline in abundance over the treatment period, characterized by a decrease in peak area. Samples taken before and after the carbon filters became more similar as processing time increased, with peak areas decreasing for pre-filtration samples and increasing for post-filtration samples for several smoke related compounds. This study serves to evaluate the feasibility of using RO to treat smoke-affected wines, and as a comparison study for treatment times between commercial and research smoked wines.

Funding Support: Washington Wine Commission, Washington State University start-up funds