The original goal of thermovinification was to handle big tonnages fast by heating the grapes and then doing a liquid phase vinification.
The benefit was that the polyphenols were extracted, the alteration enzymes were denatured, and the grape’s vegetal smells were destroyed.
More recently, and depending on the country, thermovinification now allows for the achievement of precise product goals (colour, fruitiness, volume), and numerous versions are available. Also, in some wine areas, thermovinification it´s used to increase the aroma precursors in white wines.
There are different techniques:
The wines resulting from these different techniques allow winemakers to obtain diverse wines in terms of aromas, colour and structure, as well as improving the health status of the musts.
Thermo-treatments produce hot juices with high solid content and turbidity around 3,000 NTU.
Heating the grapes results in the high solubilization of pectic polysaccharides. Before alcoholic fermentation, musts should be clarified while warm or hot to achieve a lower viscosity. This extensive solubilization is made more problematic by the inactivation of grape endogenous pectinases through heating. Consequently, the use of pectolytic enzymes is essential, even more so as thermovinification is a continuous process with key time constraints.
Techniques include pectolytic enzymes and clarification system like flotation, vacuum filtration or centrifuge.
Depectinization of must is required for future winemaking operations like draining, pressing, flotation, or filtering to be successful. Because of the enhanced enzymatic activity at high temperatures, depectinization happens quickly.
Rapidase® Thermoflash, when introduced at the start of maceration, before or after the heating step, is an effective option. This is a liquid, heat-stable pectinase, active in the presence of high polyphenol.
With an optimum activity range of 55 °C to 70 °C, Rapidase Thermoflash can be added to grapes before heating or added to the must just after, depending on the temperature reached during the heat process. The use of Rapidase Thermoflash results in a fast and reliable depectinization of the thermo-treated musts, which ensures the efficiency of subsequent steps such as draining, pressing, and clarification, regardless of the technique used (decanting, flotation, filtration, centrifugation, etc.).
With a highly qualified team of experts in many fields, Oenobrands strives to offer winemakers’ novel and scientifically sound solutions, as well as to highlight the positive synergies between its products.
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