Any hipster winemaker worth their salt seems to be making wine in concrete eggs these days.

But besides their aesthetic appeal, what effect does spending time in an egg actually have on the finished wine? We take a look at some of the key arguments in favour of this modern approach to making wine.

What is a concrete egg?

First commissioned in 2001 by Michel Chapoutier, concrete eggs are a modern innovation in winemaking based on much older principles. The shape of the egg is reminiscent of Roman amphorae, while concrete has been used in winemaking since the 19th Century.

The first egg was made by French vat manufacturer Marc Nomblot, who makes them from washed Loire sand, gravel, non-chlorinated spring water and cement. No chemicals or extra materials are added during manufacture. The unlined concrete is then treated with tartaric acid to prevent corrosion or any reactions with the wine during fermentation and ageing.

Three reasons to embrace the egg:

1. Go with the flow

Fermentation creates heat, which in turn creates convection currents that encourage the fermenting wine to move around. This occurs in fermentation vessels of all shapes and sizes, but is most effective in an egg. The egg’s shape provides a smooth, continuous surface (without corners), which allows the wine to move more freely than it would in a traditional barrel or tank during fermentation. This constant movement allows complex flavours to develop through continuous contact with lees – much like batonnage.

2. Keep cool

The thick concrete walls provide good insulation, keeping the temperature stable without the need for artificial cooling.

3. Breathe easy

Unlined concrete allows tiny amounts of oxygen to permeate and come into contact with the wine. This has the effect of softening tannins, creating a richer body and developing more complex flavours. A similar effect is achieved through barrel ageing, but concrete doesn’t impart the same oaky flavours of vanilla, spice and toast. In essence, a concrete egg allows the winemaker to retain a wine’s fruity characteristics, but without the reductive qualities of stainless steel; and add texture, but without the addition of oak flavours. Best of both!

Who makes wine in concrete eggs?

If you’d like to try some wine made in a concrete egg, you don’t have to look far! English sparkling wine producer Coates & Seely is the only winery in the UK to ferment in concrete eggs. Try their Coates & Seely Britagne Brut Reserve.

Or for something from France, try Domaine Jean Defaix’s fresh but intense Chablis 1er Cru ‘Les Beugnons’. Other producers that have been experimenting with this technique are Vivanco,  Jaboulet and Catena.