Filters in Wine Packaging
Removal of sediment and other suspended particles is critical to the initial stabilization of the wine before bottling. Unwanted particles and larger organisms are removed to reduce the amount of material that could create off flavors and aromas. The figure shows a 2 stage clarification process (housings 1 and 2).
Some winemakers may choose to use only 1 filter, depending on the level of particle and organism content at this stage of the process. Performed using depth filtration media, the filters trap progressively smaller particles at each stage.
Final stabilization requires removing the organisms that might spoil the wine after it has been bottled. There are many possible bacteria, molds and yeasts that could do that, but all can be removed just before bottling using membrane filters. Organisms can enter the bottle from two directions. The wine itself can carry organisms. The bottles can also bring organisms from the environment or from the water used to wash and rinse them.
Sterilizing is performed using a 2 stage filter process shown in the figure. The housing marked "4" is the first stage. It is usually a membrane filter with pore sizes of 0.80µm to 1.2µm. This filter captures the bulk of the organisms and protects the critical final filter from being overloaded and fouling prematurely.Learn More
Filters used for this final step are usually membrane filters with 0.45μm or 0.65µm pore sizes. The filters are designed with membrane structures that will capture the bacteria, but allow color bodies and the particulates that contribute to the “feel” of the wine to pass. Each winemaker chooses based on testing and the nature of the organisms that must be removed.
Critical Process Filtration partners with winemakers to test and validate the performance of filter designs and to create filtration systems that produce the best wine in the most cost-effective way.
Normal atmosphere is not usually allowed to contact wine during fermentation, aging or storage. The oxygen can promote the growth of undesired organisms and also cause oxidation of wine elements that create undesired flavor changes. Normal air is replaced in tanks with process gases – usually nitrogen, carbon dioxide or a combination. As the tanks are filled or emptied, the process gas “blanket” is either forced out or pumped in.
As the wine is bottled, process gas is injected into the bottle to make sure that there is little to no oxygen that can contact the wine and create the potential for oxidation or mold growth. As with the tanks, nitrogen or carbon dioxide or a combination is used.
Filters (housings marked "3") assure that no particulates or bacteria are carried by the gas to the wine. In most facilities, hydrophobic 0.22µm membrane filters are used to make sure all bacteria are removed.Learn More