Concrete-style, perhaps? Concrete has been used for thousands of years to ferment wine. Many of our Old World producers still ferment whole batches in concrete, as do more and more New World winemakers. Depending on the what they are looking to achieve they may transfer to oak for ageing, or bottle as soon as possible once the juice has settled and been filtered of any free radicals.
Crucially, concrete, like wood, is a breathable material and a little air during fermentation is a good thing. As well as reducing the chance of any off odours, which can come about when wine has no air, it helps bring a roundness and richer mouthfeel to the final product. And, as you would imagine, it doesn’t impart the oaky flavours that wood does, particularly new wood.
In addition, cement keeps a steady temperature during fermentation without the need for electric coils to heat and cool. Some winemakers in California are using curiously shaped egg cement fermenters (like that pictured above) believing that it brings uniformity to the juice, unlike the traditional cube shape where you’ll find ‘dead corners’.
Stainless steel tanks offer another option for fermentation. Despite steel not being porous, many have valves at the bottom to pump air in as required. The temperature can also be controlled to the exact degree thanks to inbuilt heating and cooling systems. Some even have mixers to stir up the lees (grape skin residue and dead yeast cells) and mechanisms to help filtrate the wine.
Château Petrus, a Bordeaux winery producing some of the best quality and the world’s most expensive wine, use concrete vessels to ferment their wine before transferring to oak barrels. If it’s been good enough for these guys for all these years, then it’s probably good enough for anyone, but like the many technical winemaking decisions to be made, a lot of it boils down to the style of wine that is trying to be achieved.
Picture sourced from Sonoma Cast Stone, the choice manufacturer for many Napa winemakers.