Concrete Egg Fermentation

I would like to direct your attention to an article that I will summarize here by Kathleen Willcox of Wine-Searcher.com regarding concrete eggs for fermenting wine here: https://www.wine-searcher.com/m/2019/08/the-incredible-concrete-wine-egg . Concrete has been used to ferment, store and transport wine since Greco-Roman times. But then French winemakers popularized oak barrels and, for centuries, oak was the vessel of choice deployed by mainstream premium winemakers for fermenting and aging wine.  In the 20th Century, of course, California winemakers were the first to adopt stainless steel tanks for fermentation. The steel tank was all about control. The tanks are easy to clean, which prevents bacteria baddies from funking up wine; the tank temperature can be monitored, which also allows for maximum micro-management of the fermentation process. They were also shiny and cool-looking.  Still, in the 1980s and '90s, reds that had spent time on oak snagged top scores from critics, as did creamy, oak-aged Chardonnays. But around the turn of the millennium, tastes changed. Buttery overoaked Chardonnays became passé, and cool climate, restrained reds became the hotness. 

Modern times 

Around 2001, Michel Chapoutier, a trailblazing biodynamic producer in the Northern Rhône, and the first winemaker to print his wine labels in braille, commissioned an egg-shaped concrete fermentation vat from Marc Nomblot, a French concrete vat manufacturer. Legend has it, his custom 2.1-meter-high egg was designed to hold 600 liters of wine. Chapoutier, who appears to embrace the more esoteric spiritual-esque aspects of biodynamic winemakers, reportedly believed the egg's spheric shape would imbue it with "celestial energy".  Nomblot must have seen the sky-high commercial potential in the design after completing Chapoutier's initial egg because the company soon scaled-up manufacturing for others; Chapoutier threatened a lawsuit several years later after Nomblot sold the company to the Bonna Sabla Group, claiming he never received proper credit – or cash-money – for the design he claims intellectual responsibility for.  Nothing ever seemed to come of the lawsuit, but Chapoutier appears to still be steaming, as he has links to articles on the contretemps still up on his website.  Trademarking something as ephemeral as a shape, Rosenblatt explains, is next to impossible.  "Concrete and wine have been used together by Etruscans and Romans," he says. "When we first got started, we received a letter from the company that owns Nomblot threatening legal action, but after a few letters back and forth, nothing ever came of it. And five years after Nomblot himself sold his company and his own non-compete expired, he himself came out with a concrete egg of his very own." 

If you visit the vineyards in France you will see these "eggs" all over, usually, side by side with traditional oak barrels. In the Rhone valley, you will see large square concrete vats and on a recent trip to Bordeaux in the Cote de Bourge I visited a small family vineyard with large square concrete vats. When I ask why they are used I am always told they help with "extraction". Gianna Kelly, winemaker at Napa Valley's Galerie, who says she uses concrete eggs to ferment and age Sauvignon Blanc and Riesling, for their superior influence on texture, complexity, and flavor.  "The big advantage of the egg is, of course, that oval shape," Kelly says. "The shape allows for natural convection of the lees all throughout fermentation, and this constant contact adds weight and complexity to the texture of our wines." 

Whether any of this truly makes any difference is clearly up for debate.  Again in France a lot of experimenting is going on.  You will also see fermentation tanks built as upright cones and at the next vineyard, the cone is upside down.  The explanation "Extraction".  So who knows in the end if the wine is good and you like it does it really matter.