Comparison between two filtration techniques for red wines

Filtration is a separation operation used in oenology to provide microbiological stabilization and limpidity of wines. Currently, in Tuscany filter-presses are the most common devices. However, they show some drawbacks in terms of required workforce and wine losses. Further, the process can’t be automated. Probably, in next future the cross-flow microfiltration, i.e. the most popular filtration system in biotechnology, food industry, and large wine estates, will replace the traditional filter-press system. However, especially in Tuscany, this method has low diffusion mainly due to the small average farms size, which cannot afford the high purchasing costs. The aim of this work is the comparison between the two above-mentioned filtration techniques in terms of operative parameters and economic costs, at working-scale. The comparisons were made using about 13000 l of Sangiovese wine produced in San Casciano Val di Pesa (FI), Italy. The effects of the two filtration techniques on wine quality were evaluated in terms of chemical and physical profiles by comparing several parameters before and after the two treatments. Also, the main operative parameters, such as operation time, energy, water, and material consumption were recorded and the break-even point of the two filtration techniques has been assessed. The results show a comparable effect of the two techniques in terms of physical and chemical parameters of the treated wines. The cross-flow microfiltration system is convenient beyond 438000 l of processed wine. Moreover, the lower variable costs, especially the required labour, make this kind of filtration more convenient than the traditional filter-press system.