The effect of winemaking techniques on the intensity of smoke taint in wine

Abstract

Background and Aims: The chemical composition and sensory properties of smoke-affected grapes and wine has been the subject of several recent studies. However, while this research has addressed early knowledge gaps surrounding the effect of smoke on grapes and wine, to date, no practical solutions that mitigate the incidence or severity of smoke taint have been reported. The current project therefore aimed to identify winery processing methods that minimise the sensory impact of smoke taint in wine. Methods and Results: Different winemaking techniques were used to process smoke-affected grapes, i.e. cold maceration, the use of different yeast strains for primary fermentation and the use of oak and tannin additives. The extent of smoke taint in the resulting wines was determined by quantification of volatile phenols using GC-MS, followed by descriptive sensory analysis. Conclusions: Applied winemaking practices showed significant impacts on reducing the negative implications of smoke exposure on the chemical composition and sensory properties of wines. Winery processing methods that reduced skin contact time enhanced fruit character, produced wines with reduced 'smoke' aromas and flavours and less apparent taint. Selected yeast strains can be used as a tool for altering smoke-related aromas, flavours, colour and chemical composition of wines. The addition of oak chips and tannin enhanced the complexity of wines thereby reducing the perception of smoke-related attributes. Significance of the Study: These findings will enable winemakers to make more informed decisions when processing smoke-affected grapes, in order to minimise the severity of smoke taint perception in resulting wine.

Winemaking practice affects the extraction of smoke‐borne phenols from grapes into wines

“…For example, guaiacol glucosylglucoside had a low extraction rate (≤7%) regardless of winemaking practice (cultivar) as also reported in Ristic et al (2011) for Shiraz and Grenache wines. Similarly, low extraction (∼10%) was observed for syringol glucosylglucoside in both Sauvignon Blanc and Chardonnay wines.…”

“…At such an elevated concentration, volatile phenols and glycoconjugated phenols impart unpleasant characters to wines, including burnt, smoky, medicinal and dirty aromas and flavour attributes (Kennison et al 2009, Ristic et al 2011, Parker et al 2012. Such wines have low consumer acceptance, and thus smoke exposure can cause significant negative economic impact on grapegrowers and winemakers (Whiting and Krstic 2007).…”

“…Recently, there have been advances in the analysis of phenols in smoke-affected fruit and resultant wines (Hayasaka et al 2010). However, estimates of the expected proportion of volatile phenols and glycoconjugated phenols extractable from grapes into wines (that can be used as industry guidelines) may not be fully inferred from these reports either due in part to the use of non-traditional winemaking (Hayasaka et al 2010) or to the limited range of glycoconjugated phenols reported (Ristic et al 2011). In smoke-affected grapes, a high proportion of glycoconjugated phenols is sequestered in the skin (Dungey et al 2011), and skin maceration and contact during winemaking may affect the extraction of these compounds into wine.…”

Amelioration of smoke taint in wine by reverse osmosis and solid phase adsorption

“…As such, methods which reduce the concentration of smoke-derived volatile compounds in wine, thereby mitigating the effects of smoke exposure, would be of benefit to grape growers and winemakers. Ristic et al (2011) investigated the effect of different winemaking techniques on the extent of smoke taint in wine and found the duration of skin contact, choice of yeast strain and addition of oak chips or tannins influenced smoke-related sensory properties. These techniques can be applied by winemakers when processing smoke-affected grapes, but do not address the issue of smoke taint in wine.…”

The Impact of Smoke From Vegetation Fires on Sensory Characteristics of Cabernet Sauvignon Wines Made From Affected Grapes

“…Winemaking practices that reduce grape skin contact have been shown to limit the extraction of guaiacol glycosides, resulting in reduced smoky aroma and flavour characteristics (Ristic et al, 2011;Kelly et al, 2014). However, glycosylated precursors may also be present in the flesh of severely exposed grapes (Singh et al, 2011), and even the free-run juice of smoke-tainted grapes can contain high levels of 4-MG and guaiacol (Kennison et al, 2008).…”