Evaluating the Effects of Sterile Filtration on the Sensory and Chemical Properties of Wine

The goal of our project is to evaluate the effects of sterile filtration on the sensory and chemical characteristics of wine. To do this, we have filtered two red wines, a Cabernet Sauvignon and a Merlot through 0.45 ?m PVDF and PES membrane filters and compared the sensory and chemical characteristics of these wines to unfiltered control wines. Treatments were expanded with the Merlot to also examine the effects of a pad filter and cartridge depth filter used as prefilters. We have examined changes in dissolved oxygen content, tannin content, and color during the course of filtration and found only minor changes. Sensory panels were trained for each of these wines and each of the treatments evaluated immediately after filtering and then on a regular basis for 9 weeks (for the Cabernet) and 4 weeks (for the Merlot) so far, with analysis ongoing. While both wines changed significantly over time in the bottle, very few significant differences were observed in aroma or mouthfeel between filtration treatments. In other words, our results thus far indicate limited impact of sterile filtration on the sensory or chemical properties of the wine, regardless of the type of filter material used. Sensory analysis of the treatments will continue to longer time in bottle for both wines. In addition, we are preparing to evaluate filtration of an aromatic white wine in the same manner over the next three months.