Phenolic Enhancement and Tannin Adjustment with Ultra Filtration.

By varying the membrane pore size and the volume of the permeate and retentate fractions (including back blending of components, where desirable), Ultra filtration produces consistent, desirable results, improving wine quality and value.

Improve the yield and quality of your product in the following areas:

• Browning Reduction: oxidized phenolics can be removed with ultra filtration. The oxidized compounds can be selectively removed based on molecular weight while desirable components are retained in the wine. In addition, many of the precursors of browning can be removed, reducing the risk of further oxidation.
• Tannin Refinement: bitter tannins of heavy press fractions can be removed with ultra filtration. The excessive tannins can be selectively removed based on molecular weight while desirable components are retained in the wine. When removing excess tannin from red wines, tannins and color are concentrated in the retentate. This concentrate can be added to other red wines that lack adequate tannin and color.
• Tint Removal: In white wines, the permeate becomes lighter, thus creating a more desirable product. Retentate from white wine hard press has been similarly used by clients to increase tannin content in red wines in lieu of commercial tannin additives.

By-product vs. loss

Ultra filtration removes wine components which may be concentrated and utilized in other wines, resulting in very small process losses overall (much smaller than with conventional diatomaceous earth or pad filtration).

Ultra filtering red wine can also provide two separate wines that stand alone on their own merits: a partial concentration of color and tannin in a red wine (10-30%) can make it more robust. The permeate may be utilized in a rosé, blanc de noir or white zinfandel type of program. If the producing winery has no available home for the permeate or the retentate, the undesired portion can be sold in bulk or distilled.