Multi-purpose optoelectronic instrument for monitoring the alcoholic fermentation of wine

The ordinary procedure to monitor the progress of wine fermentation relies on manual measurements of its density (related to sugar and ethanol content) as must gradually turns into wine. Such measurements are performed on samples extracted and analyzed at least once a day for more than fifteen days, which makes the process awkward and time-consuming for enologists. In order to contribute to the automatic supervision of the fermentation process, an instrument has been designed to simultaneously record a number of essential properties related to the wine fermentation, like refractive index n and optical densities at three wavelengths necessary to determine the chromatic characteristics of red wine, which are all liable to be recorded in real time by optical means. Additionally, we demonstrate that the variations of the refractive index during the fermentation of white must samples constitute a way to assess the status of the process as useful as the density variations traditionally recorded, which are not easily measurable on-line by optical techniques.