Concrete eggs in the winery

Concrete eggs in the winery – ask Decanter

Ask Decanter

Why are concrete eggs beginning to be used in place of more conventional fermentation tanks? Christelle Guibert provides an eggs-planation...

Concrete eggs in the winery – ask Decanter

Mason Wood-Pearce, Surrey, asks:  I’ve noticed concrete eggs are becoming an emerging trend in wineries, what’s the point?

Christelle Guibert, Decanter tastings director, replies: Concrete tanks are commonly used in wineries, but egg-shaped vessels are fairly new. Michel Chapoutier designed the concrete egg with the help of Nomblot, a French company that has been making concrete vats since the 1920s. Only Loire sand, gravel, unchlorinated spring water and cement are used, with no chemical additives or iron added.

The vessels come in two sizes: 6hl and 16hl. The egg shape gives a continuous flow to the wine as it ferments and ages, which allows a more homogenous liquid. The thick walls provide good insulation and temperature is very stable during fermentation, which avoids the need for artificial refrigeration.

Learn more: Champagne – why size matters

In my spare time, I tend 1ha of Melon de Bourgogne in Muscadet, where I make Terre de Gneiss, fermented and aged in a concrete egg for 10 months. The effect of circulation inside the egg adds depth, volume and texture to the wine. I’ve compared it with the same grape from the same terroir fermented and aged in a stainless steel vat, and the difference is obvious: the egg wine has a better mouthfeel.

The downside is that the eggs aren’t cheap, and the 16hl version weighs more than two tonnes, so transport costs are also significant – but it does add some glamour to the winery!