СLARIFICATION AND FILTRATION OF WINE

The most common method of clarification is natural sedimentation or spontaneous sedimentation, when particles that cause turbidity settle to the bottom under the influence of gravity. However, this method takes a lot of time, requires additional labor costs, tanks and space for their storage.

The Novasvit company offers an alternative: a filtration module with an FHDS membrane that works in tangential mode. This technology brightens wine in one step, giving it an attractive appearance, and also sterilizes, removing microorganisms, making it microbiologically stable.

Features and operational advantages of the FHDS membrane filtration module:

• With tangential (cross-flow) type of filtration, the work process requires significantly fewer stops for washing the membrane, as it is self-cleaning. Suspended particles moving at a high speed along the membrane fibers do not have time to attach to the fiber - they are knocked down by the following particles.

• FHDS membrane has a micron rating of 0.1-0.2 micron, which is much lower than the rating of lactic acid bacteria and yeast

• High mechanical strength and long service life of the membrane

• Low energy consumption. The membrane module works at a low pressure of 1-1.5 bar, which allows the use of pumps that consume little energy

• The equipment does not require cooling systems, which significantly reduces energy consumption during operation (compared to similar installations based on ceramic membranes)

• Membrane filter cycle of 2 or more hours

• The material of the membrane is fluoroplast, which is not a substrate for the development of bacteria

• Unique frame design and compactness: provides easy access to all technological nodes and the opportunity to significantly save space.

• Low cost of repair. The possibility of replacing a single filter fiber

Usually, the FHDS membrane filtration module is used as a final (polishing) filtration before bottling, but its technological capabilities allow it to be applied in the winemaking scheme in various processes, namely:

• To stabilize wines containing excess sugar. Even a small amount of sugar can cause re-fermentation, which is especially dangerous for bottled wine. Recovery without additional financial losses is almost impossible. Therefore, any wine containing more than 0.2% residual sugar cannot be considered biologically stable and needs to be corrected by removing the yeast through filtration

• Microbiological stabilization. The presence of "fermentable" malic acid and lactic acid bacteria in wine is always a potential problem. As a result, this leads to the formation of bottle deposits, unpleasant odors, bad taste and "effervescence" of the wine. Also, microbial nuisances associated with fermentation and various aromatic defects can occur in bulk tanks where the product is stored. In this case, the wine can be spoiled by such types of yeast as Dekkera and Saccharomyces ludwigii. And film-forming yeasts - Issatchenkia orientalis, Pichia membranaefaciens, Candia - tend to spoil wines stored in barrels.

• As an alternative to kieselguhr filters. Diatomaceous earth is a source of heavy metals that are detected in the filtered product. Its influence can lead to damage to the eyes and respiratory tract. Scientists tested three types of filters, where the filter layer is diatomite. Research results showed that they all contain cadmium, lead and arsenic. Moreover, when samples of beer and wine were passed through these filters, the concentration of arsenic in the drinks increased almost eight times compared to unfiltered samples.
  
  The results of tests and experiments were published in the American Journal of Agricultural and Food Chemistry:
  https://pubs.acs.org/doi/full/10.1021/acs.jafc.8b06062.
  
  Technologies based on the use of diatomaceous earth require large volumes of constant renewal of the filter material. After use, this material must be transported to specialized hazardous waste disposal sites, which significantly increases costs.

• Removal of extraneous odors. The production of hydrogen sulfide (“rotten egg smell”) by yeast is a complex process. Usually, the amount of hydrogen sulfide is normal, but its excess is formed when the yeast lacks sufficient nitrogen or vitamins. If the "aroma" persists after fermentation is complete, excess hydrogen sulfide and some sulfur compounds must be removed.

• Recovery of wine from the sediment that remains at the bottom of the tanks (up to 15% of the total production volume) allows you to obtain several additional economic benefits: returning the recovered wine to production, as well as reducing waste disposal costs.

• For white wine, instead of the wort settling stage, which consists in the separation of suspended materials by decantation. As an added bonus, this avoids excessive use of sulfur dioxide to inactivate wild microorganisms within the fresh wort for controlled fermentation with selective yeasts

• For red wine instead of a drum filter that rotates to reduce the turbidity of the red must.

• For sweet wines, to stop alcoholic fermentation without using excessive amounts of sulfur dioxide.

Wine is a complex environment that contains many components, dissolved substances, and colloids. The parameters of these components differ from each other depending on the grape variety, climate, cultivation and production technology. This feature allows winemakers, by combining the properties of the components and the capabilities of different methodologies, to create the individual appeal of each wine, but such combinatorics can lead to unexpected results in the finished product.

The technology of the Novasvit company - a smart combination of process parameters and membrane characteristics - is a solution to extremely complex tasks and a guaranteed result without unnecessary trouble