The Use of Concrete Eggs in Wine Aging

Concrete tanks have been used in winemaking since the early 1900s. Many enormous tanks used for fermenting and aging wine were constructed on-site, then filled with wine. In contrast to wooden vats, they were long-lasting and sanitary and did not harbor molds and bacteria that could compromise the wine.

They also helped to reduce temperature fluctuations during the winemaking process by providing thermal stability. Egg-shaped tanks may even have magical properties, according to some. These ancient amphorae were used in regions like Northern Italy and the Republic of Georgia to keep the wine cool and prevent it from breaking during transportation.

How the Use of Concrete Eggs in Aging Wine Has Evolved

Stainless steel tanks appeared to replace concrete tanks in the mid-20th century, but many older tanks are still in use in many wine regions. However, in 2019, concrete eggs returned as concrete tanks, and they started appearing all over the place. Winemakers and guests have been mesmerized by the massive egg-shaped tanks.

That may be because winemakers constantly strive to improve their products, but most agree that visual appeal has a place in the wine industry. It has also been discovered that concrete could be used for micro-ox (introducing a tiny amount of oxygen) or barrel aging without the oak aromas and flavors. The temperature is more evenly regulated, and the convex shape of the egg also helps keep the lees in place.

Concrete Eggs, in Bodega El Esteco

Concrete Tanks, Cones, and Cubes Today

Today, tanks in the form of boxes are being reinstalled, but these are much smaller than the massive tanks that were previously in use. As a result, most of these structures are manufactured in factories rather than poured into pre-existing forms. Stackable and mobile, these smaller “cubes” hold the wine equivalent to four barrels and provide the advantages of small containers with greater space efficiency, easier cleaning, and the benefits of oak, but with no oak flavors.

Aside from aesthetics, the cooling coils and thick concrete walls in the tanks protect the contents from sudden temperature changes. Concrete is also easier to clean than wood, which can harbor contaminants in its staves and heads. Apart from cleaning them with water, wood tanks must have water in them when they are not holding wine. Concrete adds minerality and helps tannin develop and become softer, making the wine more feminine.

The Future of Concrete Tanks in Wine Storage

Whether concrete is porous to the air is a hot topic. Winemakers and researchers dispute the claim that “micro-oxygenation” is possible. The tanks that are being used are made with multiple coats of reinforced concrete, some of which have been reinforced with fiberglass and integral heating and cooling tubing.

After neutralizing the slightly alkaline material with tannic acid, their interior surface is so smooth that they do not need a coating and are inert enough to have little effect on the wine’s chemistry. Stainless steel is also the least expensive material, and wood and concrete are comparable in terms of the initial investment.

Still, concrete is more durable and could last up to 40 years. The eggs also present an exciting New Age appeal. In conclusion, concrete tanks are increasingly used in wine production today, and they are certainly a new old tool in the never-ending quest for better wine.

Also read: The History of Oak Barrels