We now have eight five-tonne, burgundy-shaped, open-topped fermenters at our Margaret River winery.
Concrete is a natural insulator and will stabilise the temperature of its contents. This stability makes for a smooth and gradual fermentation, because there are no temperature fluctuations. For the same reason, concrete is also ideal for storing and aging wines.
The concrete tanks are also porous and that's where it beats stainless steel. With a gradual introduction of oxygen, the wine can breathe and evolve. Wine fermented in concrete has the round mouthfeel of wine fermented in oak, but it has much greater purity of fruit flavour and intensity of colour.
Concrete does a very good job of showcasing a wine's true terroir. Oak can mask those distinctions, but concrete doesn't add, remove, or mask anything. It lets the fruit shine through to be a true statement of the place it was grown.
Here's a great article by Cathy Howard from the WINE & VITICULTURE JOURNAL SEPTEMBER/OCTOBER 2015, where our winemaker Trent Carroll speaks of the pros and cons of winemaking in concrete tanks, offering a technical perspective on how he creates such high quality, natural wines.
It's the aromatic lift and freshness of the primary fruit characters, combined with the resulting texture that are the biggest wine quality benefits in using the elliptical concrete tank compared with the vat and barrels - Trent Carroll, Head Winemaker.