Sugar reduction in musts with nanofiltration membranes to obtain low alcohol-content wines

Our aim here is to study the sugar reduction in musts to obtain wines with a slight alcohol reduction by nanofiltration. Specifically, sugar reduction is achieved by two successive nanofiltration steps. To test the method, we have worked with two types of musts: a white must from Verdejo grapes and a red one from Tinta de Toro grapes. The musts obtained from the nanofiltration treatment have been mixed with untreated must or with the retentate of the first nanofiltration stage in a proportion adequate to reduce the alcohol content of the resulting wines by 2°.To verify the effectiveness of the process, each of these musts has been fermented along with an untreated control sample of the same must. The alcohol reduction in the wines has been satisfactory. However, a slight loss in the color and aroma of some compounds has been detected.

Research highlights▶ A single step process of nanofiltration has been proposed and tested to reach small reduction of the alcohol degree of red and white wines. ▶ This has been accomplished by reducing sugar in musts. ▶ The resulting wines have been analyzed, chemically and from an organoleptic point of view noting that they are quite similar to the untreated ones..