There’s a saying in the wine industry: “It takes a lot of beer to make wine.”

That’s certainly the case for Gemtree winemakers Mike Brown and Josh Waechter.

Over a few brews the pair decided to shake things up with their next drop – specifically, ageing their wine in the very earth from which it was sourced.

“We just began talking about what ifs and how we can achieve the best possible outcomes with the resources we have,” says Brown. “We thought, ‘The winemaking process starts in the vineyard, so why not return the wine to its roots to age and continue its connection to the earth?’”.

The pair’s single-vineyard McLaren Vale shiraz was buried in a wax-coated French oak barrel underneath the vines where the grapes were hand-picked. The soil provides a natural temperature-controlled cellar for the wine to mature, says Brown.

The concept of ageing a wine in the ground isn’t entirely foreign. Georgian winemakers have done it for centuries. More recently, cellars have been dug into the ground in parts of France to provide an ideal, temperature-stable environment to age the wine in. But the act of returning a barrel to the vineyard is something quite new.

Still, when gas and electricity can create a perfect environment for storage and maturation, why bother? “Our finance control [officer] Christine certainly had her concerns,” says Brown. “She started calculating the price per litre, doing the sums of just how costly it would be if this were to be a failure.” But for him and Waechter it was a question of “why not?” and “what if?”

So how does it stand up to its above-ground counterparts? Tasted against wine made from fruit from the same vineyard (aged above ground) it had more “… freshness, vitality, purity and finesse,” says Brown.

Gemtree was established in the 1980s and converted to bio-dynamics (a holistic and philosophical approach to farming and agriculture) in 2007. “The last few years now, we’ve really seen a step up in the quality of fruit coming off our vineyards and it led us to ask ourselves: ‘How else can we improve?” says Waechter.

The shiraz grapes spent five days on-skins before finishing its primary and secondary fermentation in-barrel. From here the barrel was given a coat of wax to protect it while in the ground. Then during the winter equinox on a “fruit day” – all part of the biodynamic cycle – the barrel was placed into the ground before being removed on the next equinox some eight months later. The whole process is 100 per cent natural; no added yeast, no sulphur at any stage, nothing.

Only 240 bottles of the inaugural 2016 release is on the market. But the team has just unearthed barrel number two, from this year’s vintage. For them, it’s not a flash in the pan attention grabber but a reflection of their curiosity, drive and passion to achieve the best results.