Since ancient times filtration is being used for clarifying wine. After fermentation, wine is a complex and cloudy product often not accepted by the consumer. In fact, when the wine is cloudy, or when a customer finds deposits on the bottom of the bottles, he immediately thinks about a sign of deterioration or misproduction. Limpidity is the first visual quality that a consumer expects from wine. It must be a permanent quality throughout the storage period whatever the storage condition. The key roles of filtration are therefore to provide BRILLIANCE and MICROBIOLOGICAL STABILIZATION of wines.
1. BRILLIANCE in wine is evaluated by measuring turbidity which is expressed by the nephelometric turbidity unit (NTU). The above table summarizes the correlation between turbidity and the visual appearance of wines. After filtration, turbidity must be less than at least 2 NTU.
2. STABILIZATION can be physico-chemical and microbiological. Physico-chemical stabilization prevents organic, inorganic hazards and deposits after bottling. Microbiological stabilization is guaranteed by microfiltration because of the elimination of yeasts and bacteria that can alter wine. Until few years ago, wineries were equipped with DE filters. This technique quickly showed its limits in terms of quality, product loss and high labor requirements. Today, crossflow filtration is widely used and appreciated in the wine sector because it allows to obtain the two essential elements of brilliance and stabilization without delay.
Bared has been designing and manufacturing cross flow filters since the 2000s and thanks to over thirty years of experience of its founder in membrane technologies, hundreds of customers benefit from the advantages offered by cross flow filtration.