Page 22 - Grapevine SeptOct 2021
P. 22

In The Winery

               polishes wine and gives it a softer finish. It helps a   screens before filtering. This method involves cov-
               wine be more microbially stable and preserves the    ering a stainless-steel or nylon screen with DE and
               integrity of the product. Although it is not a health   pouring wine and DE through the screen for fil-
               or safety requirement, most modern and commer-       tration. It’s a meticulous process that may require
               cial wines are filtered in some way.                 supportive plates, a pump, a rotating drum and
                                                                    a rotary vacuum filter. Respiratory and eye pro-
                         Options for Wine Filtration                tection are required during use due to health and
                                                                    safety concerns about handling DE. Crossflow and
                 It’s easy to become overwhelmed by the number      centrifuge filtration offer safer alternatives.
               of wine filtering options, especially when new to
               winemaking or making a style of wine for the first     For crossflow filtration, the wine moves with sig-
               time. For example, there’s pad filtration, mem-      nificant force and pressure across a porous mem-
               brane filtration, earth filtration and reverse osmo-  brane. Wine is pumped through a partially enclosed
               sis. Other methods include ultrafiltration, crossflow   pathway and produces juice with very concentrated
               filtration, ceramic membrane crossflow, racking      particles. There is a high initial investment associ-
               and cold stabilization.                              ated with crossflow filters, including replacement
                                                                    membrane costs, which is why many small and
                 The first step in removing suspended solids is typ-  mid-sized wineries don’t use them.
               ically using a coarse depth filter. Depth filters catch
               particles but aren’t effective in removing microor-    Ultrafiltration is a crossflow method using a mem-
               ganisms from wine. Next, tighter pad depth filters   brane with a nominal relative weight cutoff of
               are used. As a final step, winemakers can use mem-   10,000 per molecule. Winemakers use this method
               brane filters to catch microorganisms.               to enhance the flavor of wine and make it more
                                                                    stable because ultra-filtration gets rid of all sizable
                 Pad filtration involves running wine across a pad,   particles and proteins.
               typically made of cotton, polyethylene or cellulose.
               Pads typically require a setup with a plate and        Ceramic membrane crossflow is an advanced tech-
               frame and a pump to move the wine. Filter pads       nique that incorporates pressing mechanisms. This
               work by having wine flow into the rough side of the  technique ensures high levels of clarity and reduces
               pad and then out from the smooth side. Different     product loss, especially crucial for high-value wines.
               pads are used for red and white wine, but choosing  Durable ceramic membranes can deliver automatic
               the right filter pads depends on the total filtering   production cycles and keep a winery’s environmen-
               surface area. Although pads are inexpensive, they    tal impact low.
               are designed only for one-time use. There can be
               high leakage rates and long setup times with pads,     Racking is a non-obtrusive way to filter wine and
               too.                                                 involves moving wine between barrels. This method
                                                                    is only somewhat effective, as some wine remains
                 Cartridges offer an alternative to pads. They use   behind in the bottom of the barrel with the sedi-
               housings, leak less than pads and are cleaner to     ment during the manual transfer.
               work with; however, they are also costlier and
               require more maintenance. It’s important to store      Aside from filtering, cold stabilization is a meth-
               them properly so they last a long time and make      od used to clarify wine. This method requires the
               the investment worthwhile.                           winemaker to deeply chill the wine to remove tar-
                                                                    taric acid crystals from the product.
                 Membrane filtration uses a cartridge made up
               of nylon, glass fibers, polypropylene or cellulose             Heyes Filters’ Xflow System
               to facilitate screening techniques. This method is
               often used for microbial stabilization purposes and     Among the various options available for wine
               is the final step before wine is bottled.            filtration, Heyes Filters’ Xflow System stands out.
                                                                    They manufacture their products in the U.S., simpli-
                 Some winemakers use earth filtration using dia-    fying the search for spare parts and support while
               tomaceous earth, a soft rock ground into a white     potentially limiting downtime if service is required.
               powder. DE serves as a coating on filter pads or     Based in Torrance, California, Heyes Filters special-
               Page 20                       The Grapevine • September - October 2021                          877-892-5332

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