Fine filtration for fine wines: Backflushable BECO filter cartridges improve wine quality and purity

Wine is an integral part of French culture. Enjoyed with meals and with friends, a good quality wine embodies the essence of ‘savoir vivre‘ (knowing how to live). Winemaking is regarded not only as a science but also as an art, with expertise passed down through the generations. Removing impurities during vinification is essential in delivering a high-quality drink. In white and sparkling wines that have not undergone tartaric stabilization, precipitation of potassium bitartrate crystals, also known as ‘wine diamonds’, can occur. If not removed before bottling, these crystals can affect the visual appeal and mouthfeel of the wine, diminishing the overall drinking experience. Maison Joseph Cattin wanted to find a reliable, in-house process that could be used across their range of white and sparkling wines. BECO^® depth filter cartridges from Eaton provided the solution.

Background: Winemaking: where tradition and technology combine

Maison Joseph Cattin is an independent, family-owned winery based in the Alsace region of France. For 300 years, generations of the Cattin family have been devoted to viticulture and winemaking, cultivating the region’s unique soils and rich grape varieties to produce a noble and elegant collection of Alsace wines. Each generation of talented winemakers has contributed to the success of Maison Joseph Cattin and today they own more than 160 acres (65 hectares) of vineyard - one of the largest family-owned estates in the region. Classified either under the Grand Cru appellation, AOC Crémant d’Alsace or AOC Alsace, the vineyards are located in Voegtlinshoffen, Steinbach and Colmar.

While the winemaking process is rooted in the accumulated knowledge and passion of their ancestors, Maison Joseph Cattin embraces modern means of production that will help it to uphold the highest quality while preserving the unique taste of its fine wines. The process begins with careful selection of the grapes, which then undergo a period of maceration. The maceration time varies depending on the grape variety. The grapes are then pressed and fermented under temperature-controlled conditions. The wine is aged in vats in a cool cellar before being stabilized, filtered and bottled.

Challenge: Diamonds are not a winemaker’s best friend

Preventing the formation of crystals in bottled white and sparkling wines is a key challenge for quality-focused winemakers like Maison Joseph Cattin. In these wines, tartrate crystals, commonly known as ‘wine diamonds’, can precipitate when the wine is chilled or aged. Although harmless, these crystals can be visually unappealing and, if they reach the glass, may affect the wine’s mouthfeel and overall drinking experience.

There are several ways to prevent crystal formation in bottled wine, with electrodialysis and cold stabilization being the most common.

Electrodialysis is an additive-free method that uses ion-selective membranes and an electric field to remove tartrate crystals from wine. While effective, it is often costly, less flexible and typically requires specialized external service providers.

Cold stabilization, by contrast, is a more accessible and cost-effective method. It involves chilling the wine to encourage the controlled precipitation of tartrate crystals. This process can be accelerated by adding auxiliary agents like potassium bitartrate, commonly known as cream of tartar, which initiate and guide crystal formation. Once the crystals have formed, they must be removed to ensure wine clarity and stability. Traditionally, this has been done using plate and frame filters with diatomaceous earth (DE). The resulting DE/cream of tartar mixture can be sold for tartar recovery and resale. However, modern filtration systems using depth filter cartridges eliminate the need for DE, resulting in cleaner by-products and higher-value cream of tartar for reuse or resale, leading to cost savings and process efficiency.

Maison Joseph Cattin originally opted for electrodialysis which made them reliant on an external supplier visiting the winery periodically to conduct the process. This dependency forced the winery to produce and store thousands of gallons (gal)/hectoliters (hl) of white and sparkling wine for tartaric stabilization to suit the limited availability of the electrodialysis equipment. They were keen to find an alternative stabilization method that would give them greater flexibility and greater control without affecting the quality of their organic wines. However, space for new equipment was at a premium.

“Being in full control of our wine production during such a key quality step was more important than the cost of electrodialysis,” explains Sylvain Kamm, Oenologist and Head of Production at Maison Joseph Cattin.

After thoroughly discussing their requirements, Eaton - through its distributor Schiélé - proposed a solution involving cold stabilization followed by filtration to remove precipitated crystals, using a technique that had previously been successfully implemented at a winery in Italy.

Solution: Successful trials optimize wine filtration process

Eaton initially supplied Maison Joseph Cattin with a test system consisting of 10 depth filter cartridges, 30 inches in size, housed with 6 blind plugs in a 16-fold cartridge housing, allowing them to test the proposed solution on site. The filters were tested both after cold stabilization, using cream of tartar as an auxiliary agent and in preparation for bottling to improve wine filterability. The trials were successful, demonstrating high filtration efficiency rates. The final setup includes two five-cartridge housings running in parallel, integrated onto Cattin’s existing filtration skid. This configuration optimized the system design while reducing both capital investment and operational costs.

“Eaton answered all our questions and offered good support throughout the decision-making process,” says Sylvain. “It was exciting to take a solution already proven in Italy and adapt it to suit our winemaking processes here in France. The final filter configuration only required minor adjustments to optimize its performance and deliver the purity that we desired.”

The final Eaton filtration system incorporates BECO PROTECT PG depth filter cartridges with a retention rate of 0.3 µm. These depth filter cartridges feature multi-layered polypropylene fleeces, graded from coarse to fine, which act like a funnel and remove a wide range of particles. This configuration provides high volume capacity, enabling the efficient and easy recovery of valuable cream of tartar through filtration for internal reuse or potential resale. The design also facilitates cleaning, allowing the filters to be regenerated by backflushing and ensuring the captured crystals are thoroughly flushed out of the filter cartridge. The filter cartridges are installed in BECO INTEGRA CART cartridge housings made of AISI 316L stainless steel. The design of the filtrate chamber supports efficient filtration, while the welded drain connections at the inlet and outlet, combined with the surface finish, make cleaning easier and help maintain the highest standards of hygiene.

Results: Flexible, compact filtration puts winery back in control

The new Eaton filtration system, equipped with advanced filter cartridges and housings, has enabled Maison Joseph Cattin to regain full control over its winemaking process. By allowing on-site cold stabilization, the system streamlines operations, optimizes cream of tartar recovery and eliminates dependence on external electrodialysis equipment.

The parallel filter configuration allows one cartridge housing to be used for filtering wine while the other is backflushed and regenerated. This ensures continuous operation when needed, delivers optimal filtration results every time the system is deployed and extends the service life of the filter cartridges. Additionally, the same cartridge housings can be fitted with different filter cartridges, making the system versatile for various filtration tasks across different wine types.

In just five months, Maison Joseph Cattin filtered more than 264,170 gal (10,000 hl) of wine using Eaton‘s cartridge filtration solution. That’s the equivalent of 40 tanks of 6,600 gal (250 hl) each, processed at a flow rate of 1,320 gal (50 hl) per hour, resulting in over 1.3 million 25 fl oz (75 cl) bottles of perfectly filtered wine.

Sylvain concludes: “Our Eaton filtration solution has put us back in control. It’s so flexible and easy to handle and it’s made us far more efficient. The footprint is very small and the enclosed housing design ensures that no wine is lost during filtration after tartaric stabilization. The backflushing feature is really beneficial, enabling us to use the filters repeatedly with no risk of contamination. We couldn’t ask for a better solution!”