Drink: the newest shape in fermentation

Amélie Barrot, Chateau des Fines Roches.
Amélie Barrot, Chateau des Fines Roches.

In wine, as in fashion, everything old is new again.

After turning their backs on concrete for fermentation, many astute winemakers are giving it a second look; this time around in egg-shaped vessels which echo a form from antiquity, the amphora, or what the Georgians call quevri.

Cedar Creek Estate and Okanagan Crush Pad (OKP) are probably the best known of Canadian wineries opting for concrete eggs for fermentation. Several wineries in Ontario use them, such as Jordan’s Pearl Morissette Estate, as well as Cliff Lede and Domaine Carneros in California, and Chilean biodynamic/organic producer Emiliana.

Concrete never really went out of fashion in the old world. It is Michel Chapoutier who is credited with commissioning the first egg-shaped tank from French concrete vat maker Nomblot in 2001. The relationship went south after the sale of Nomblot to a larger concern and remains fractious.

Why egg-shaped? Their attributes are based on the shape, and on the material. Wines fermented in them have a softer style with good aromas and fruit. They allow a more even temperature control, with less precipitous temperature shifts. The shape allows better movement and lees stirring.

“There seems to be almost a convective current that helps to keep the lees in suspension, and lees contact is always a good thing,” says Michael Bartier of Okanagan Crush Pad.

They are porous, depending on the tank, allowing the fermenting wine to breathe. They allow ambient yeast to flourish.

Eggs at Okanagan Crush Pad.
Eggs at Okanagan Crush Pad.

“It’s a lot easier to get the uninoculated ferments going, “ says Michael. “The ups and downs of temperature are not as dramatic. I think that’s way more comfortable for the yeast and the wine.”

Chateau des Fines Roches, a family-owned domain in Châteauneuf-du-Pape, has a few small eggs they use for their top cuvees. “We like the shape,” says Amélie Barrot, with the Gallic shrug. “It’s very natural.”

Winemakers, like chefs, are not always about to give you all their secrets.

On the other hand, Steve Rosenblatt, CEO of Sonoma Cast Stone is excited about the technical parameters of the egg-shaped tanks he makes for several North American producers. It takes about 110 hours to make one standard sized, egg-shaped unit.

“It’s a four-part mold that holds 1,800 litres,” he starts to explain.

“We work from the outside in using a fibrous concrete with lots of glass fibre. Next day, we’ll attach a coil for heating and cooling the egg to the outside shell, then attach the two halves together.”

Size and the ability to control temperature are the fundamental differences between the European and American styles. The European egg is smaller, with no heat/cold controls, only the natural attributes of the stone in play. The American egg holds more juice and can be temperature-controlled.

How did OKP wind up with the first Sonoma Cast Stone Egg in western Canada? When they designed the winery, they had all stainless, renowned for temperature control, a clean ferment and flexibility.

“It was Alberto,” says Michael, referring to Alberto Antonini (Poggiotondo) their consultant on all things wine-related.

“When he saw the plan he said ‘you must have some concrete.’”

OKP now has six. What juice gets the egg treatment?

“If it comes from Switchback (home vineyard), it takes priority,” says Michael. “Beyond that, which wines are going to benefit and which wines deserve the premium? The eggs are a much more expensive piece of equipment — it works out to about $7 per litre capital cost compared to $2 or so for a stainless tank.”

Game changer or passing fad? Only time will tell. Not everyone is a fan. Another highly regarded Okanagan winemaker thinks they are a fad, and not worth the money.

Michael Bartier has now worked with the egg-shaped fermenters over two vintages.

“I do like them an awful lot, and I plan to buy more.”

Certified sommelier Mary Bailey teaches WSET and French Wine Academy courses for thr Art Institute of Vancouver (AIV) in Edmonton.