Concrete Tank and Vat Aging
Concrete vessels give winemakers a thermally stable, subtly oxygen-permeable middle ground between inert stainless steel and flavor-extractive oak.
Concrete tanks, including traditional vats, modern egg-shaped vessels, and amphora-inspired forms, have surged back into winemaking as alternatives to oak and stainless steel. Prized for their thermal inertia, slight porosity, and flavor neutrality, concrete vessels encourage gentle oxidative development and enhanced mouthfeel without imparting oak-derived aromatics. The modern egg-shaped concrete fermenter was first commissioned in 2001, sparking a global revival of interest in this ancient vessel material.
- The first modern concrete egg was commissioned in 2001 by Rhône biodynamic producer Michel Chapoutier, designed in collaboration with French manufacturer Marc Nomblot, whose company has been making concrete wine vats since 1922
- Nomblot, founded by Etienne Nomblot in Ecuisses in the Saône-et-Loire region of France and now owned by the Béton Concept group, produces eggs in two standard sizes: 600 liters (6hl) and 1,600 liters (16hl), priced from around €3,000 to €6,000 at source
- A Nomblot 1,600-liter egg weighs approximately 2,000 kg, requiring a crane for placement; a 470-gallon (roughly 1,780-liter) egg from California's Sonoma Cast Stone costs around $14,000
- Concrete's semi-porous matrix allows gentle micro-oxygenation, sitting between fully inert stainless steel and the more permeable surface of an oak barrel, softening tannins and promoting aromatic complexity without adding wood-derived flavors
- The ovoid egg shape generates a natural convection current during fermentation, keeping lees in suspension and producing a self-stirring effect similar to manual battonage, building body and texture
- Concrete's high thermal mass buffers temperature fluctuations during fermentation, reducing the need for artificial refrigeration and providing a more stable fermentation environment than stainless steel
- Concrete vessels can last for decades with minimal maintenance, unlike oak barrels which typically require replacement after 4 to 7 years of useful life; the interior surface gradually develops a tartaric acid lining that further stabilizes the wine contact surface over successive vintages
What It Is
Concrete tanks and vats are vessels made from food-grade concrete, typically a blend of cement, sand, gravel, and water with no chemical additives, used to ferment or age wine. The category spans several forms: traditional rectangular or cylindrical vats long common in European cellars, modern egg-shaped vessels introduced commercially in 2001, and amphora-inspired forms such as the Nomblot Dolia. Properly cured concrete presents a chemically stable surface that is flavor-neutral, distinguishing it clearly from oak's extractive character and from the complete inertness of stainless steel.
- Historically, concrete tanks were lined with epoxy to prevent wine contact with raw cement; unlined natural concrete is now increasingly used by producers who value the slight mineral interaction
- Nomblot constructs its tanks in a single mold from only natural concrete, using Loire sand, gravel, unchlorinated spring water, and cement with no chemical additives or iron reinforcement
- Traditional vats can hold many thousands of liters; modern eggs from Nomblot range from 600 to 1,600 liters, while Sonoma Cast Stone in California offers comparable sizes for the North American market
How It Works
Concrete's semi-porous structure allows slow oxygen ingress through microscopic capillaries in the material, enabling gentle oxidative aging that falls between stainless steel's complete inertness and the more pronounced oxygen transmission of an oak barrel. As one Napa winemaker put it, concrete offers 'a wonderful middle ground between a stainless steel tank and an oak barrel, which allows much more oxygen to get into the wine.' A key additional mechanism in egg-shaped vessels is thermodynamic convection: the disparity of volume and temperature between the top and bottom of the egg creates a natural vortex that keeps lees in suspension, replicating the effect of battonage without manual intervention. Concrete's high thermal mass also slows any changes in temperature, providing a stable fermentation and aging environment.
- Micro-oxygenation through the concrete walls can promote tannin polymerization, soften astringency, and improve color stability in red wines
- The natural lees-suspension vortex in egg-shaped tanks builds body and structure, reducing the frequency of manual lees-stirring required compared to barrels or steel tanks
- The limestone-rich composition of concrete (calcium carbonate) can slightly raise wine pH on extended contact, which winemakers should monitor, particularly for high-acid white wines
Effect on Wine Style
Wines aged in concrete tend to develop enhanced textural complexity, showing a silky, integrated mouthfeel compared to those aged exclusively in steel or oak. The gentle micro-oxygenation supports phenolic development in reds, contributing to softer tannin edges and greater mid-palate weight, while whites maintain varietal purity and gain a subtle mineral character and textural richness. As Argentina's Sebastian Zuccardi notes, concrete is a neutral environment so 'the end product shows you simply grape and place.' The absence of wood-derived flavor compounds keeps the focus on fruit and terroir, while the slight oxidative influence prevents the reductive character that can appear in wines held in airtight stainless steel.
- Red wines show softer, more integrated tannins and increased mid-palate volume compared to equivalent steel-aged wines
- White wines gain textural weight and subtle minerality while preserving delicate primary aromatics, without the vanilla or spice of new oak
- Concrete suits a wide range of varieties including Malbec, Syrah, Grenache, Chenin Blanc, Sauvignon Blanc, and Chardonnay, among many others
When Winemakers Use It
Concrete is especially appealing to producers who want an alternative to oak's dominant flavor profile but find stainless steel too neutral, particularly for premium or artisanal wines where terroir and varietal purity are paramount. Biodynamic and natural wine producers favor concrete for its alignment with minimal-intervention philosophy. Nomblot tanks are used at estates as prestigious as Domaine de la Romanée-Conti, and concrete is now found across Bordeaux, Burgundy, the Loire Valley, Piedmont, and California. However, concrete is not universally embraced: some winemakers find eggs space-inefficient and costly, and the scientific evidence for specific sensory benefits beyond what stainless steel with added micro-oxygenation can achieve remains limited.
- Zuccardi Valle de Uco in Argentina has committed extensively to concrete eggs and amphora-shaped vats for its Malbec program, citing flavor neutrality and gentle micro-oxygenation
- Cakebread Cellars in Napa uses a concrete egg for fermenting and aging Sauvignon Blanc, finding it adds character and minerality beyond what stainless steel provides
- Concrete is particularly effective for aging periods of roughly 6 to 18 months, bridging the gap between barrel-aged and steel-aged approaches
Notable Producers Using Concrete
Michel Chapoutier (Northern Rhône, France) was the pioneer, commissioning the first modern concrete egg from Nomblot in 2001. In Italy, Joško Gravner (Friuli-Venezia Giulia) is renowned for aging wines in buried Georgian clay qvevri vessels, not concrete; his neighbor Radikon ferments in large Slavonian oak barrels. Both are important figures in the amphora and natural wine movements broadly, though neither uses concrete specifically. Niepoort in Portugal's Douro has used large-format old oak and concrete vats for aging its table wines. In California, Cakebread Cellars, Continuum, St. Supéry, and Frog's Leap have adopted concrete tanks and eggs for a range of varieties, while in Argentina, Zuccardi Valle de Uco has built its winemaking philosophy around concrete vessels.
- Nomblot developed specialized tank shapes in collaboration with Domaine de la Romanée-Conti and Michel Chapoutier, among other renowned estates
- Zuccardi Valle de Uco uses dozens of 1,000- and 2,000-liter concrete eggs alongside custom round vats and amphora shapes for Malbec fermentation and aging
- Gravner's 2001 vintage was the first fully fermented in imported Georgian qvevri, with around 47 underground beeswax-lined clay vessels used today at the estate
Maintenance and Practical Considerations
Concrete vessels require careful preparation before first use: new tanks benefit from an acid rinse to neutralize residual alkalinity from the cement, followed by sulfite treatments to sanitize. Unlike barrels, concrete does not require seasoning with water when empty, and its longevity can exceed several decades with basic upkeep. Over successive vintages, a natural tartaric acid lining builds on the interior walls, gradually reducing direct wine-concrete contact and further stabilizing the vessel. The main practical challenges are weight and inflexibility of placement: a standard 1,600-liter Nomblot egg weighs around 2,000 kg, requiring a crane for repositioning, and drastic temperature changes can cause stress cracking.
- Cleaning involves hot water rinses and a brush; aggressive caustic chemicals should be avoided to preserve the concrete surface integrity
- Concrete is fragile under pressure during cleaning; careful, gentle washing practices are essential to avoid wall damage
- Long-term cost per use can be favorable compared to oak, given concrete's multi-decade lifespan versus the 4 to 7 useful years typical of an oak barrel
Wines aged in concrete develop a refined textural elegance: a silky, integrated mouthfeel with a faint mineral or chalky quality, absent of oak spice or vanilla. Red wines show softer, more rounded tannins and increased mid-palate volume, with fruit character that feels concentrated and true to variety. Whites maintain bright primary aromatics, whether stone fruit, citrus, or white flower, while gaining a subtle creamy texture and greater overall weight. The overarching sensory impression is one of purity and place: concrete-aged wines express grape and terroir clearly, without the interference of wood-derived compounds, and with a gentle, living quality that evolves in bottle over time.