SO2WINE:  Free & Active SO2 measurement portable device. 


The invention consists in an electrochemical probe made of integrated electrodes, and a measurement module for a direct measurement of free and molecular SO2.

The most useful fraction of “free SO2“ is the molecular or “active SO2” and its amount varies with pH, temperature, alcoholic degree and the concentration of free SO2. Its oenological interest is of major importance because it protects the wine against contamination by microorganisms, provided its concentration is high enough. Thus, for an optimal conservation, the “active SO2“ rate should remain between 0.35 and 0.6 mg/l, while free SO2 values of 25 mg/l and 30 mg/l are recommended for red and white wines, respectively.



Stéphane ARBAULT
Alexander KUHN
Institute of Molecular Sciences (ISM, UMR 5255)


Nom : Christophe Zabawinski Titre : Chef de Projet Sciences de la Vie Mail :




Due to its antiseptic and antioxidant properties, sulfur dioxide (SO2) is one of the main additives involved all along the wine-making process, from the harvest to the bottle.

To date, there is no easy and straightforward method offering a direct estimation of the “free” and “molecular” (active part) SO2 fractions, and thus an optimization of the wine treatment.

Our electrochemical solution offers a simple, efficient and competitive tool to measure free and molecular SO2 directly in the winery, thus providing productivity gains.


This fully portable device could be used directly in the winery, without any sample preparation, and should instantly estimate the concentration and type of SO₂ present in wines (sample, bottle or barrel). This precious information will help the winemaker to better control the wine-making process and thus may both improve the quality of wines and reduce treatment costs.


This technology is protected by a patent application


Maturation with Aquitaine Science Transfert led to develop a portable electrochemical probe to measure the free SO2 directly in the wine cellar, easily and quickly.

By | 2017-05-02T15:53:14+00:00 mai 2nd, 2017|