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A Technical Guide for Wine Producers
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WHAT'S UP IN THE VINEYARD AND CELLAR
Improved filtration with BECOPAD
Filtration is one of the basic processes used during the vinification process and consequently an important cost factor in winemaking. Ever since the development of tangential filtration, also known as cross flow, filtration technology had not changed much until the introduction of BECOPAD late last year by a German company, Begerow & Kie.
BECOPAD is a pure filtration medium that entails various benefits for the wine industry in respect of environmental pollution, improved filtration, regeneration, adsorption, effectiveness and the reduction of micro populations.
The reduction of environmental pollution
Water consumption and the removal of cellar waste are two of the most important factors when determining the environmental impact of wine cellars. The new cellulose filtration medium offers considerable savings in water consumption and waste. It consists of pure cellulose that derives from plant cell walls and is therefore 100% biodegradable. What is more, it contains no diatomaceous earth or perlite and is free of minerals. Winemakers are therefore able to obtain improved filtration in a more environmentally friendly manner.
Improved filtration
Because of the cost and labour factors involved in filtration, improved filtration effectiveness is a huge priority. Filtration trials at cellars have shown that BECOPAD has several advantages in this regard. Bigger wine volumes may be filtered without changing filters, consumption costs are reduced, less water is used during preparation, the preparation time is reduced and the wet strength of the filter medium is greatly increased, which considerably improves the washing of filtration sheets for recycling. Although the manufacturers contend that the volume throughput is improved by 20%, trials, both in Australia and locally, have shown an increased throughput of 20 to 38%.
Trials in Sicily and Australia have shown that BECOPAD makes it possible to filter white wine after red wine, provided the correct washing and regeneration processes are followed. The particularly low adsorption qualities, pure cellulose medium, as well as improved wet strength of the medium makes it possible to use the same filtration sheets for different types of wine. In both trials the filtration sheets were washed after the first day’s red wine filtration, first with cold water and then with hot water at 70°C, and the filter was kept overnight in warm water.
Adsorption and performance
The modus operandi of filtration media in sheet or sieve filters is based on mechanical separation, surface filtration or electro-kinetic adsorption (the so-called zeta potential). Mechanical separation is the retention of particles inside the structure of the filtration medium, which usually becomes more compact with increasing depth. Surface filtration is the retention of bigger particles on the surface of the filtration medium, when particles are unable to penetrate the structure of the filtration medium. The zeta potential of filtration media is dependent on the cation charge of the medium. As a result thereof, particles with a negative charge will be adsorbed into the filtration medium. The lower the zeta potential of a filtration medium, the less colourants and flavourants of the filtered wine will be adsorbed. BECOPAD, which consists of cellulose only, has a very low zeta potential and consequently does not remove colour from red wines.
Improved effectiveness with coarser media
The effectiveness of a depth filtration medium is determined by the filterability of the wine, flow speed, capacity and mechanical stability. Trials with BECOPAD have shown that coarser grades such as 450 and 550, remove more micro-organisms than conventional coarse filtration. BECOPAD 550 (2.9 - 5.0 micron), for example, reduced the bacteria count of a wine from 2.55 million cells/ml to 10 cells/ml with a differential filtration pressure of 1.5 bars (Carty, 2009).
The new BECOPAD technology definitely enables the environmentally friendly filtration of wine in a less costly, more effective way.
The local supplier of BECOPAD is C&F Wine Consumables.
References
Carty, Lee. 2009. New depth filtration technology ticks efficiency, volume and "green" boxes.
The Australian & New Zealand Grapegrower & Winemaker, April 2009: 72 - 76.
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