Page 22 - Grapevine SeptOct 2021

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-
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