Can Cold Soaking or Massive Sulfur Maceration Prior to Fermentation Increase the Quality of Pinot noir?
Pascal Wegmann-Herr* and Marie Welk
*Institute for Viticulture and Enology (DLR-Rheinpfalz),
Breitenweg 71, 67435 Neustadt, Germany
(pascal.wegmann-herr@dlr.rlp.de)
Compared to other red cultivars, Pinot noir grapes have significantly lower anthocyanin concentrations and more seed tannins and display a general tendency toward unripe tannins. Prefermentative maceration, or cold soaking (CS), aims to lengthen the time of maceration in the absence of alcohol. Another technique gaining popularity among winemakers is adding high sulfur dioxide (SO2) concentrations to the grapes to impede the onset of fermentation. However, there are few reports concerning the impact of these techniques on the chemical composition and sensory characteristics of the resulting wines. The aim of this study was to examine prefermentative cold and sulfur maceration as strategies to improve Pinot noir wine quality. Five days of cold soaking at 5°C and SO2 additions up to 200 mg/L were compared to classical skin fermentations without SO2 addition and a typical addition of 30 mg/L (control), keeping the total maceration time, fermentation temperature, and punch down frequency identical. Spectrophotometry (color intensity and tone), LC-DAD (total anthocyanins and flavan-3-ols), LC-ESI-ToFMS (Vitisin A and Vitisin B), Harbertson-Adams assays (characterization of phenolic composition) and HS-SPME H/C enantio-MDGC-MS-MS (for α- and β-ionone and β-damascenone) were used to analyze the differences among treatments. Additionally, a descriptive sensory analysis was conducted with a trained tasting panel. Multiple factor analysis revealed that the cold soak treatments and high sulfur treatments separated well from the control and SO2-free wines. Significant increases in color intensity and hue were observed during sensory analysis in both cold soak and high SO2 addition wines. SO2-treated variants lacked fruitiness and exhibited sweaty, sulfur off-flavors. The same wines contained significantly lower β-damascenone concentrations.
Funding Support: no Funding Source
