Why Concrete Eggs for Riesling?

The Walla Faces 2010 Riesling is “Concrete Egg Vinted”. The futuristic appearance may be snazzy, but the real benefit is its myriad of effects on the wine.

Like oak, concrete is porous. Thus, the wine is able to breathe, facilitating richness and complexity without leaving an oaky flavor behind. Like barrel aging, the porous nature of the concrete allows the wine to slowly aerate, providing layers and softness. Concrete-fermented wines also typically maintain a lot of fruitiness.

Additionally, the tank imparts a minerality that lingers on the palate. Because Walla Faces used both concrete and stainless steel for our 2010 Riesling, it took on the characteristics of both stainless steel- and concrete-vinted wines. Like stainless steel-vinted wines, this vintage has a crisp, refreshing effect, without sacrificing its rich complexity.

The Walla Faces Concrete Egg Fermenter, produced by Marc Nomblot.

The Walla Faces Concrete Egg Fermenter, nestled in some barrels!

Concrete has been used in winemaking since the early 19th century, when some wines were fermented in huge, rectangular concrete vats. Although the material is a classic, the egg shape is an innovation! The first concrete egg fermenter was commissioned in 2001 by Maison M. Chapoutier, a winery in the Rhone region of France. French manufacturer Nomblot, who has been producing concrete tanks since they opened in 1922.

Nomblot’s tanks are produced using washed sand from the French river Loire, gravel, non-chlorinated spring water and cement. They are treated with tartaric acid before use. Because the tanks are unlined, they are able to provide an effervescent mineral flavor to the wines they contain.

The egg shape provides in important function: it facilitates circulation. Because there is a one degree temperature difference between the top and the bottom of the egg, the wine slowly circulates through the tank. Since there are no corners, the wine won’t get stuck in every nook and cranny. The result? The wine stays more uniform throughout the fermentation process. As a result, the finished product will be more structured. No one wants a flabby Riesling!

Because the wine is slowly moving through the tank, it also has more contact with the lees, the dead yeast. As the lees break down, they release many compounds such as amino acids, polysaccharides and fatty acids. This so-called “lees aging” helps create additional complexity, as well as an appealing mouthfeel and aroma.

Given the benefits of the concrete egg fermenters, why are they still so rare in the United States? Concrete egg fermenters are a lot of work! For starters, winemakers must take special precautions to prevent the acidic wine from corroding the concrete tank. The length of fermentation is also longer in concrete, as opposed to stainless steel. Finally, with Nomblot as the exclusive maker of concrete egg fermenters, it can be difficult to access them. We had to import the tank from France. As Walla Faces co-owner Debbie put it, “[It] cost a fortune to get it here.”

The concrete egg may add some additional work, but the best things in life are worth working for! The best wines in life? Doubly so.