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This article originally appeared in the February 2017 edition of Grapegrower & Winemaker.


By switching from round to square tanks, a Californian winery was able to increase capacity by 28 percent and reduce water use by nearly 90 percent. John Intardonato reports.

Being square is often considered a negative. But in the wine business, if it can give you both a financial and quality edge, keep your winemaking under one roof without added construction costs and revitalise an old storage shed, perhaps going square can turn out to be pretty hip.

Such seems the case for Sonoma’s historic Rodney Strong Vineyards in Sonoma County, California. By converting to square tanks, Rodney Strong created room to install an additional 17 fermentation tanks in a building that originally could only accommodate 40.

This Russian River landmark has been innovative and cutting-edge since Strong left his Broadway dancing career to go west. He was one of the pioneers in creating the AVA system, helping develop both the Chalk Hill and Russian River AVA designations. He also introduced mail-order wine sales and personalized bottle labeling. The winery has never shied away from trying something new.

“We needed tanks that would hold 6000 gallons (22,500 litres) and handle 20 tonnes each,” said Justin Seidenfeld, the winemaker who helped design the system.

“With regular, round fermenters, we could only squeeze in 40 tanks. With the square design, not only were we able to install as many as 57 tanks, which will now accommodate our full harvest, it has left us some extra room for any surprises. The round tanks left us 20 percent short of our needs. With the square tanks we were able to increase our capacity by 28 percent in the same space.”

“With regular, round fermenters, we could only squeeze in 40 tanks. With the square design, not only were we able to install as many as 57 tanks,”


In a unique partnership with La Garde of Quebec, Canada, a 50-year-old manufacturer of high-quality, stainless steel products, the Rodney Strong winery became the largest square tank winery in the world.

“Our goal is to be sustainable and to maximize our efficiency,” said Seidenfeld. “These tanks were designed and built especially for our new winery, which we created from an old 11,000 square foot  (3300 square metre) warehouse. The building was already on our property and was just sitting here, taking up space. It was called ‘the bone-yard’ because it’s where we kept all our old stuff.”

The new facility, however, is now a state-of-the-art, out-of-the-box winery intended to handle the company’s new ultra-premium Bordeaux blend. Its fruit source is from a newly planted 200-acre vineyard leased from the 19,000-acre Cooley Ranch. Located north of Lake Sonoma and west of Cloverdale, the vineyard sits between 800 and 2,000 feet elevation. Rodney Strong has a 70-year lease for 390 acres on the property, and the money paid will help to preserve and maintain the remaining land as a permanent ag preserve.

“We estimate that the vineyard will produce about 1000 tonnes, and we want to process this exceptional fruit all under one roof. We discovered that if we used the standard round fermenters in the building, there was only capacity for 40 tanks; that’s only about 80 per cent of the harvest,” Seidenfeld said.

He said he started looking around for alternatives and got the idea for the square tanks when he visited the La Garde booth at the Unified Wine & Grape Symposium in Sacramento several years ago. The problem, at the time, was that the company only made small tanks – just 1000 to 4000 litres. However, La Garde director and designer Jostran Lamontagne told Seidenfeld the company could custom-build tanks to the winery’s specifications. Lamontagne then sent his engineers to the winery. The tanks were built and installed in time for the 2014 Clooney Ranch harvest.

“With their increased capacity they actually cost us less per capacity than if we had to expand the facility,”


While the La Garde units were double the cost of similar-capacity round tanks, Seidenfeld said that difference has already been paid back.

“With their increased capacity they actually cost us less per capacity than if we had to expand the facility,” he said. “It’s an investment that paid itself off in one and a half years of winemaking.”

Savings on Water and Energy Costs

The tanks have produced additional benefits in production and labour costs, time saved and wine quality, according to Seidenfeld.

“Because the tanks are made of sheet metal rather than rolled steel, they’re three times thicker than round tanks. This allowed us to nano-polish the interior to a very smooth surface so wine residue doesn’t get into the pores. This makes it so easy to clean the tanks with just hot water. No caustic chemicals or excessive scrubbing is needed to remove the wine deposits.”

As a result, Seidenfeld claims they have reduced their water use by almost 90 percent and reduced their cooling and utility costs by 50 per cent.

The tanks, he added, have improved wine quality through enhanced extraction and more balanced fermentations.

“Because the tanks have a wider area, the cap is spread out more, which gives a better skin contact with the juice. This also provides better cooling of the must. We have more consistent fermentation curves, and it reduces heat spikes. It gives a cleaner fermentation with no off characters that we don’t want in our wine,” he said. “The cooling package is actually reduced in size because the tanks are cooling each other. With square tanks there is more metal to metal and less air space to keep cool.”

According to Seidenfeld, the tanks are completely enclosed and can be alternately used as storage, blending and maturation containers. Each tank can also be used for smaller quantities.

“It has six cooling jackets, with the upper and lower jackets on separate controls. They are very versatile containers. I have used these tanks to ferment as little as four tonnes and as much as 22.”

Winery owner Tom Klein is equally enthusiastic.

“We wanted to get a certain quality in this new wine and wanted a special fermenter to accomplish this in the space we had. If we didn’t have these specific goals in mind, we never would have tried these tanks,” said Klein. “Now, when you think about it, it doesn’t make sense to put round tanks in a square building. We saved a lot of wasted space. We’re finding that we’re using less water and less energy. The results are remarkable. Justin was very clever.”

Wine Trials: Round v Square Tanks

Seidenfeld said he is a believer. And he has carried out blind tastings to test the quality.

The consensus: the square tanks produced a better wine.


“As an experiment, we fermented the fruit in round steel, 600-litre oak barrels and square tanks. All were processed in the same way, with 21-day skin contact.”

The consensus: the square tanks produced a better wine.

“We made a winery out of nothing,” he added. “The old shed has been revitalised from top to bottom. Even a special, sloping floor of resin and fibre was added to support the tanks, along with heavy insulation, extra stabilizers and an extensive catwalk.” He said he is getting two full runs: the earlier-ripening Pinot Noir and the Clooney Ranch varietals.

Although excited about the great fruit and the exceptional new facilities, Seidenfeld is modest about his own participation. “Square tanks have been around a long time so we didn’t reinvent the wheel. When we began to think about the tanks, we were a little hesitant but not anymore,” he added.

This article was first published in the Dec 2015 edition US Wine Business Monthly and has been used with permission.