Winemakers from Austria to Chile are going to work on an egg to add complexity to their wines, reports Sally Easton MW.
The first egg vat was commissioned in 2001 by Michel Chapoutier, following discussions and design between Chapoutier and French vat manufacturer Marc Nomblot, whose company has been making concrete wine vats since 1922. The shapely historic connection to Roman amphorae was not coincidental.
The vats are made without using chemical additives, according to Nomblot, from washed Loire sand, gravel, non-chlorinated spring water and cement. The concrete is unlined and must be treated with tartaric acid solutions before use. Since 2001, Nomblot has sold some 800 of the vats, which are usually 6hl or 16hl in size.
Concrete has been used successfully since the 19th century for winemaking, but the egg shape itself is new. Regardless of shape, temperature fluctuation is quite small, although the concrete is liable to crack if temperatures get too high.
A critical factor is a continuous flow of liquid. Biodynamic farmer Werner Michlits, of Meinklang in Austria, observed a temperature difference of around 1°C between the top and bottom of his eggs, which Michlits said enhances the slow, continuous flow of the liquid.
Gilles Lapalus of Sutton Grange Winery, who was the first to import egg vats into Australia in 2005, points out: “With this sort of shape there are no dead corners, so there is a better uniformity of the composition of the liquid, in terms of temperature especially.” And he adds: “The fermentation kinetics seem more regular, and it’s less reductive than stainless steel.” However, he was quick to point out that he’s done no strict comparisons.
Eben Sadie in South Africa was an early adopter, and has been using eggs for his white wines for eight years. He uses the 6hl size, in which he says the fermentation temperature is stable. Sadie explains that, in an ambient cellar temperature of 16°C, “My white fermentations are about 20°C without any cooling. I don’t inoculate and natural ferments are cooler than yeast additions”.
Explaining the effect of the circulation, he says it “adds more depth and structure to the wine, but doesn’t let wines go flabby; they stay linear, dense and tight. It’s finer stitching”.
Lapalus agrees, saying: “In my experience with Viognier, we can have long time on lees with a good control on reductive character, giving a lot of texture to the wine. And I don’t see any effect on the acid profile.”
A similar result has been seen at California’s Spottswoode, which has been using egg vats since 2006 to create a blending component for its Sauvignon Blanc. Winemaker Jennifer Williams said she wanted “to increase minerality and weight in our white wines. Concrete preserves the natural character of Sauvignon while also adding richness and body. The [eggs] act like oak barrels in creating texture, [but] without imparting vanillin, spice, etc. They preserve fruit flavours and aromas like stainless does.”
Another often-cited benefit is a micro-oxygenation akin to that seen with oak, without imparting oak flavour, and avoiding the reductive conditions of stainless steel. Sadie says: “I tried to find an alternative vessel to wood that could breathe, but that doesn’t give taste of wood, which is not part of terroir. Concrete allows a higher level of purity, site and place.”
Back in Australia, Julian Castagna has also started maturing his Viognier, which is used in the flagship Genesis Syrah. He says: “Concrete had a freshness that surprised me and I thought was really interesting.” And for him this was enough to do his own experiments: “At the level of wine we make, to try and increase quality by even 1% is worthwhile. My gut tells me it will add another level of complexity.“