Sensory profile: a tool to characterize originality of wines produced without sulfites

Abstract

AIM: A trend to reduce chemical inputs in wines exists, especially sulfur dioxide (SO2). This additive is widely used due to its antioxidant, antiseptic and antioxidasic properties. During without sulfites vinification, bioprotection by adding yeast on harvest could be a sulfites alternative. With extension of this wine market, sensory impact linked to sulfites absence and/or sulfites alternative should be evaluated. That’s what this approach proposes to do, focusing on sensory characteristics of wines produced with or without SO2 addition during the winemaking process.

METHODS: Wines were elaborated from Merlot grapes of two maturity levels according to three modalities: SO2, without SO2 and bioprotection on harvest (mix of Torulaspora delbrueckii and Metschnikowia pulcherrima). SO2 modality was sulfited throughout the winemaking and aging processes whether other modalities received any addition. After two years of aging, sensory studies were carried out with a specific panel for one month. First, descriptors were generated to differentiate the wines, then panelists were trained on these specific descriptors for five sessions and finally wines sensory profiles were elaborated.

RESULTS: The panel generated thirteen descriptors to differentiate the wines on which they have been trained: nine olfactive, three gustative and one trigeminal. After training, the nine presenting a consensus between judges were finally used. Wines without SO2 were characterized by freshness (mint and coolness) and cooked black cherries; bioprotection by fresh blackcurrant and with SO2 by smoke. Hierarchical clustering applied to this sensory approach lead to significantly differentiate wines produced with or without SO2.

CONCLUSIONS:

This approach allow to highlight sensory specificities of without sulfites wines. Therefore, with a dozen of descriptors, tasters could differentiate wines which have been sulfited or not but cannot differentiate among not sulfited ones those who have received bioprotection from those which have got any addition, regardless grapes maturity level.