Frog’s Leap has all the time been an exception amongst Napa Valley wineries. The Williams household, who based it, had been preaching the natural gospel lengthy earlier than most of their neighbours. They’ve treasured previous vine varieties which can be much less trendy and extra obscure than essentially the most worthwhile Cabernet Sauvignon. They even appear to have managed an amicable and profitable transition from one technology to a different. And John Williams and his son Rory had been Napa’s first to undertake a winemaking observe that has been spreading everywhere in the world.

Wooden, particularly oak, has lengthy been the fabric of selection for ageing and, usually, fermenting wine in. It clearly has an affinity with the flavours of wine and, most significantly, encourages simply the correct quantity of oxygen wanted to stabilise and make clear it. Historic civilisations could have used clay pots and the like, however picket barrels succeeded amphorae as containers for each storage and transport as way back because the third century AD.

In direction of the tip of the twentieth century, it turned a badge of honour among the many world’s wine producers to boast about what number of new French oak barrels they purchased every year. Certainly, for a lot of wine producers the world over, the best annual value is their funding in new barrels, which maintain the equal of about 300 bottles. They’ll value $1,000 every and could also be used for not more than three years.

Up to now, an oak barrel — certainly, ageing wine in any respect — was considered a luxurious in poorer components of Europe. In direction of the tip of the final century, they usually hoped to interchange their previous concrete vats, usually as massive as a room, with new stainless-steel tanks which can be a lot simpler to wash. The deserted wine co-ops that now dot the Languedoc, as an example, are full of those ghostly vessels, usually nonetheless encrusted with the purple tartrate crystals deposited by pink winemaking. A few of the extra energetic wine farmers would use dynamite to rid themselves of those concrete dinosaurs.

But concrete has turn into more and more à la mode in wine manufacturing. This century many wineries have experimented with big concrete egg-shaped containers, that are alleged to encourage motion and helpful contact with the lees. And glamorous new wineries, equivalent to these designed for the glitzy likes of Château Cheval Blanc in St-Emilion and Masseto in Bolgheri, boast concrete fermentation vessels in all sizes and styles. Maybe the truth that, regardless of the prevailing trend elsewhere, Bordeaux’s most costly wine, Petrus, has all the time been fermented in concrete has performed a small half in encouraging this phenomenon.

Nevertheless it applies solely to fermentation. Most advantageous wine continues to be aged in wooden, even when producers and shoppers have broadly taken towards the pronounced “oaky” flavours related to new, small barrels so the dimensions and common age of the oak barrel or vat has been rising.

At Frog’s Leap, they’re flying within the face of present observe in northern California, the place demand for brand spanking new French oak barrels has lengthy been so nice that the most important French coopers established outposts there a few years in the past.

In addition to utilizing an array of concrete eggs, which John Williams describes as “space-eaters”, they’ve put in two 13,000-US gallon concrete “rooms” during which they age their Chardonnay and Sauvignon Blanc. They’re thrilled by the extra texture of their wines. Certainly, so happy are they by this retro materials that they’ve additionally invested in 100 small, sq. 240-US gallon concrete cubes for his or her unusually zesty Zinfandel, with “tremendously thrilling” outcomes, says John Williams. (The outcomes for Cabernet Sauvignon are much less conclusive; it appears the Bordeaux pink wine grape actually appreciates its keep in oak, maybe as a result of it permits extra oxygen ingress.)

One in every of concrete’s nice benefits over oak is its regular temperature, however its attraction to the Williamses can also be each monetary and ecological. “It takes one 75-year-old oak tree to supply two barrels for wine use and people barrels have a usable lifetime of three to 5 years,” says John Williams.

Against this, the lifespan of a concrete container is limitless, decreasing their carbon footprint.

In reality, producing the cement for concrete is comparatively heavy on sand and greenhouse gasoline emissions however a minimum of the Williams are sourcing their new vessels near residence — from Sonoma Solid Stone, whose principal enterprise is producing sinks, simply over the hill in Petaluma. The Frog’s Leap concrete containers need to be rinsed every year with a heavy answer of tartaric acid (the most typical acid in wine) however are nonetheless simpler to keep up than oak.

Such enthusiasm for ageing wine in concrete could also be uncommon in Napa Valley but it surely has turn into more and more widespread in Spain the place some see concrete (and, in some areas, clay tinajas) as a healthful revival of native custom.

Extremely revered vintner Telmo Rodriguez determined that his new Lanzaga vineyard in Rioja can be all-concrete, reproducing how wine was made there within the Thirties. He was inspired by his companion Pablo Eguzkiza, who had expertise of creating wine in concrete when working at Petrus in Bordeaux. “I actually like picket tanks,” Eguzkiza admits, “however they’re very tough to preserve in good situation (they all the time need to be full).” Lanzaga’s concrete cylinders maintain as much as 100 hectolitres (2,640 US gallons).

Different outstanding followers of concrete embrace Michel Chapoutier of France and Australia, who has lengthy favoured it for grape varieties significantly liable to oxidation equivalent to Grenache, and Sebastian Zuccardi of Argentina. When Zuccardi constructed a brand new vineyard in Valle de Uco, excessive in Argentine wine nation, he intentionally centered on concrete vessels as a result of he wished to precise native characters unaffected by the flavour of oak. He too factors out that he’s merely reviving a fabric that was widespread domestically within the Thirties.

But not everyone seems to be satisfied. On the opposite aspect of the Andes in Chile, Burgundy-trained winemaker François Massoc is very sceptical of what he describes as “concrete tanks in every kind of shapes rising like mushrooms everywhere in the world”. Whereas concrete evangelists argue that wine can “breathe” in concrete, he claims “they neglect that the internal pores [of the concrete tank] aren’t linked with the outside pores, so that is unattainable”.

Concrete-aged wines definitely don’t seem like starved of oxygen, and sometimes appear to have freshness

Williams and Chapoutier counter that so long as the concrete is unlined, it isn’t oxygen outdoors wine containers that works its magic however minute quantities of oxygen trapped within the skinny layers of the inside of the container. Concrete-aged wines definitely don’t seem like starved of oxygen, and sometimes appear to have freshness and extra texture, although maybe I’m imagining a sure graininess.

Massoc can also be involved about potential contamination from chemical compounds utilized in making them, noting that, “Cheval Blanc made a big research earlier than selecting their concrete, and we have to keep in mind that Kees [this famous château’s chief adviser] is a geologist, so he knew what he was doing. That’s the explanation why they’ve an exquisite and technically extraordinary vineyard. Others? I don’t know.”

Ageing in concrete could be very a lot in keeping with the present vogue for pure fruit flavours. It appears to be nicely suited to many a energetic white wine and to reds for comparatively early consumption. However for complicated reds designed for lengthy ageing, the coopers in all probability want lose no sleep.

Tasting notes on Purple Pages of JancisRobinson.com. Extra stockists from Wine-searcher.com

Observe Jancis on Twitter @JancisRobinson

Observe @FTMag on Twitter to search out out about our newest tales first