Duncan Hamm* and David Spector
*Chr. Hansen A/S, Boege Alle 10-12, Hoersholm, 2970, Denmark (gbdha@chr-hansen.com)

Smoke taint in wines, resulting from grapes affected by smoke from nearby wild or man-made fires, is a serious problem in many winemaking regions. The molecules responsible for smoke taint are present in wines in two forms: ‘free’ volatile molecules or non-volatile glycosides ‘bound’ to sugar moieties. To date, little knowledge exists regarding the impact of the bacteria responsible for malolactic fermentation (MLF) on the release of free taint compounds from their bound counterparts. To determine whether the unbound ‘free’ concentration of seven known taint compounds was in­creased during MLF, six commercially available Oenococcus oeni strains were studied. MLF was carried out in three commercial wines, all categorized as highly tainted by the wineries producing them. The concentrations of ‘free’ and ‘bound’ smoke taint compounds were measured before and after MLF. Upon completion of MLF with the six cultures, no significant increase in the concentration of ‘free’ taint compounds was found. This suggests that for wines with a low level of smoke taint, conducting MLF with these six O. oeni strains will not increase the negative effects of smoke taint. Furthermore, MLF with these cultures could be combined with a suite of other wine­making techniques such as carbon-fining, shortened maceration, yeast selection, and the addition of oak adjuncts and tannin products to manage the level of smoke taint in an impacted wine.

Funding Support: Chr. Hansen A/S