Two heat maceration methods and extended hold time: effects on phenolic outcomes in Pinot noir must and wine

The extraction and stabilisation of phenolic compounds can be challenging for Pinot noir winemakers. Two heat maceration methods (thermal heat exchange and microwave maceration) were developed and applied at laboratory scale. Both methods were compared with a control (crush and destem, eight days fermentation on skins) for phenolic extraction outcomes in must and wine. Phenolic outcomes were quantified using UV-visible spectroscopy and the Modified Somers Method. Significant differences were seen between the three treatments, with microwave maceration most often showing the highest concentration of phenolics. The two heat methods were also evaluated for impact on phenolics in must over an extended hold time (5 hours at 70„aC) and hold time was shown to have a significant impact on anthocyanin, tannin and pigmented tannin concentration in musts for both of the heat treatments. The findings are relevant to industry as they demonstrate the importance of hold time in managing phenolic extraction withheat maceration, and further development of the novel microwave maceration method may lead to industry efficiency by avoiding extended time in tank for extraction (eg extended maceration).