Great Wines Come From Eggs?!
By: Jeff Cox
Back before Prohibition, many California wineries fermented their grapes in big, rectangular concrete tanks. Concrete worked well because the acid in the grape juice reacted with the cement used to make concrete, coating the inside of the tanks with a layer of calcium tartrate that was impervious to further penetration by the grape acids.
Prohibition destroyed the California wine industry, and it didn’t really recover until the 1960s and 70s, when a few wineries went beyond producing jug wines and started making better wines based on Bordeaux varieties and practices. Those old blocky concrete tanks didn’t seem proper for the new fine wines, and so vintners started using stainless steel fermenting tanks and then French oak for post-fermentation elevage.
Then a few years ago, Don Van Staaveren, winemaker at Three Sticks Wines in Sonoma, remembered that Europeans had for centuries used concrete fermenting tanks to make excellent wines. He contacted his friend Steve Rosenblatt, president of Sonoma Cast Stone, and the two developed a 500-gallon, concrete, egg-shaped tank. After a couple of years of trial and error, they offered the eggs for sale and got orders for a dozen eggs in 2011, 26 eggs in 2012, and 54 orders and counting in 2013.
The concrete is slightly porous, allowing minute amounts of oxygen to reach the fermenting must inside. Because of the egg shape that narrows at the top, the rising bubbles of carbon dioxide from the fermentation are pressured to move more quickly, and this rush of gas within the must sets up moving streams within the liquid.
“When you look in when it’s fermenting, you can see it moving, like an ocean,” Rosenblatt says.
The constant movement of the must aids in the disintegration of the skins that releases flavor, aroma, and color compounds into the new wine.
Wineries are experimenting with these vessels at this stage, but if they like the results, we wine lovers may one day read a label that says, “Fermented in an Egg.”