Concrete Eggs, A Modern Trend That Is Here To Stay
During the last decade, Argentina wineries filled up on these vats. But, what are they exactly for?

Concrete Eggs, in Bodega El Esteco
Containers in winemaking are a key element in the different stages of the process: maceration, fermentation, aging. And as they are not an exact science, each winemaker has his own formula utilizing different materials, shapes, origins, and techniques.
During the last decade, Argentina wineries filled up on concrete eggs. These vats started to replace stainless steel tanks, cement pools, and even oak barrels during the winemaking process
So we asked ourselves, what are they for? What is the advantage of that shape? We wanted to know, so we went directly to the sources.

Sebastián Zuccardi, among concrete eggs
Sebastián Zuccardi, Chief Winemaker of Zuccardi Valle de Uco, believes that the use of concrete eggs let us recover “part of the history of Argentine viticulture since concrete has been present since the ’30s and was a bit relegated during the last decades”.
Origin
It was during the ’90s, when Michel Chapoutier, owner of Maison M. Chapoutier in France, devised an ovoid shape partly because of his biodynamic philosophy to make wines and partly because of the shape of Roman amphorae and Kvevri vessels originated in Georgia.
Egg Effect
These vats grant a vinification with less intervention, according to the experts, avoiding battonage and remontage (pumping over). How? The basic rule that you have to know about them is that the oval shape generates a temperature contrast in the center and on top, and this generates a natural movement of the wine from the bottom to the top, and then to the sides.

Ovoid Natural Movement of Wine
One of the consequences of this effect is that the wine yeast remains in suspension during fermentation, avoiding contact with oxygen on the surface. This grants character and texture, according to Juan Pablo Michelini, the winemaker at Zorzal Wines.
About the concrete eggs’ performance during aging, he sustains, “The aromatic intensity and varietal expression grow, the expression of terroir grows… the vintage, the soil and the climate are revealed. Everything is boosted. It has a distinctive input comparing it to other vessels in terms of expression and stabilization. Also, for colder years or early harvests, the micro-oxygenation helps the green components to get transformed“.
Another positive point, according to Juan Pablo, is that concrete eggs strengthen the character and sensations of the wine in the mouth since the tannins get softened during the micro-oxygenation; naturally, a very important duty in Gualtallary wines like his.

Juan Pablo Michelini, from Zorzal Wines
At Anaia Wines, a brand new project led by Osvaldo del Campo and Patricia Serizola, they went further and they designed their own concrete containers, slightly different from the classic ones. They have a mate-shape (hot infusion with yerba mate, classic Argentinian drink) and they are meant to be in constant pendular movement.

Mate-shape concrete containers in Anaia Wines
According to Sebastian Zuccardi, who is always looking for materials that don’t affect aromas and flavor, “concrete is a material that respects the expression of the place“.
In the pursuit of honest expression of terroir, concrete eggs seem to have achieved a relevant role for most of the winemakers. Claudio Maza, winemaker at Bodega El Esteco (Cafayate, Salta), explains that they already produce 1.5% of the total production in these containers, but the percentage increases significantly on high-end tiers.

Claudio Maza, at El Esteco Wines
Last but not least important, concrete also offers an energy cost reduction, basically due to the isolation from temperature changes.

Concrete Eggs
Summary:
- Respectful of aromas, because of concrete’s characteristics.
- Intervention reduction, because of its natural ovoid movement of wine.
- Cost reduction, because of natural temperature control.
- More texture and volume, especially in white wine.
- Softer tannins in red wine.
Everything indicates that this kind of containers has a dynamic and long future in modern winemaking. Time (and you as a consumer) will tell!