Subsea Estate is the southern hemisphere's first operation dedicated to ageing wine underwater

Winemakers in Margaret River love to talk about the maritime influence and the effect of having ocean on three sides. It’s part of the winemaking lore in a region adept at telling a good story. Now, Subsea Estate, based at the southwestern tip of Western Australia, is writing its own chapter. Billed as the first subsea winemaker in the southern hemisphere, it is using a method that leans on secondary fermentation and maturation in patented underwater vats. 

It’s almost 10 years since I last interviewed co-founder Brad Adams. As we meet on the harbour at Augusta, he beckons me to a demountable office and points at the wall. Framed and hung is the decade-old cover story I’d written about greenlip-abalone ranching which Brad, a second-generation abalone diver, had pioneered in Flinders Bay, just shy of the Cape Leeuwin Lighthouse where the Southern and Indian Oceans meet. In season, you’ll see whales breaching offshore and the tourist boats that track them, and you’ll see the abalone boats slip in and out of harbour, the divers who maintain the prized seafood aboard. And now, a new venture, using French-developed technology, that offers more than just ocean cellaring. 

The journey, Brad says, began with what they’re now calling their “ocean signature process.” A collaboration with nearby winemaker Glenarty Road saw the release of a 2019 Fathoms Cuvee, so named because it was matured 10 fathoms (60 feet) deep in the Southern Ocean. A rudimentary experiment, a few hundred bottles were lowered onto the abalone lease in cages. It created not just a wine of interest but a sea life encrusted bottle that was a talking point for visitors to Glenarty Road’s feted cellar door and restaurant. It’s a process that you’ll also see at Ocean Aged Wines in Victoria who first created their Vintage Cuvée back in 2012.

With an existing abalone lease and a team of divers, boats and equipment, most of the necessary infrastructure was already in place.

“We did a bit of research during the process and came across a company in France called Wine Reef,” he says. “A fellow there, Emmanuel Poirmeur, has been researching this underwater winemaking technique for over a decade. It’s actually subsea winemaking in its purest form.” Brad describes a to-and-fro with the French patent holders who envisage a global network of wine reefs. They made multiple visits to the region before a joint venture was finally inked.

What impressed them most, Brad says, were the practical conditions. In France, they are limited by a small lease, and that they must pay top dollar for divers. In Margaret River, with an abalone lease of 400 hectares, and a large team of commercial divers, boats and lifting equipment already in place, there are no such restrictions. It was a meeting of capital and existing infrastructure on one side, and patented technology on the other. 

Additionally, the “hundreds of thousands of litres of wine that we can access [in Margaret River], as well as excess capacity at a lot of wineries that we can tap into to make our wines, means we don’t have to invest in that infrastructure at this early stage," says Brad.

Simon Hanley, winemaker and General Manager at Subsea Estate, explains that the Wine Reef technology is the key differentiator between what they’re doing and other forms of ocean cellaring. Traditional methods in amphora were static and not on yeast, and cellaring underwater was more a factor of refrigeration. Brad pulls up a video on his phone. It shows a vat anchored to the seabed, swaying like a fairground punching bag. He bangs his hand on the table to emphasise how the pressurised vats are battered from side to side, particularly during winter swells.

The vats are anchored to the seabed and battered by the ocean currents.

Underwater, there are a lot of variables in terms of pressure, movement, and temperature, depending on the season. “The ocean really will determine everything,” says Simon. There’s a measured difference between Subsea Estate’s first-release reds and whites. He says the semillon, chosen for its “nice tropical grassy characteristics” and suitability to Margaret River, has come out in an “autolytic, yeasty, richer, full-bodied style.”  

Reds are their own story. “In 30 years of winemaking I’ve never barrel-stirred a red on yeast. The surface area of the yeast cell is quite tacky and so what it’s doing is staying up in suspension. It’s adhering a lot of the tannins, so they’re falling out. The flavour profile of the wine changes quite significantly in the red. You’re getting softer tannins which increases the apparent fruitiness and drops the acidity, because the yeast consumes some of the acid. You get a nice, fuller, richer mouthfeel.” 

Subsea Estate has crafted a Pure Ocean range which, as the name suggests, is made solely with the Wine Reef technology, and a Land and Sea range which is a blend of both their ocean- and land-cellared wines. As you’d expect, the Land and Sea is more entry level in terms of price, with Pure Ocean (both the semillon and the shiraz) being three times the cost. But Brad and Simon are confident in the value, such is the unique nature of this process within the Australian market.

Now that their first vintage has been released, there’s talk of the future. Long term, there are plans for a winemaking facility on the harbourside, complete with a seafood-focused restaurant, which plays into a wider tourism vision and synergies with the abalone ranch. On the winemaking side, it’s open season. “It’s really interesting where we can go with this,” says Brad.

The use of Wine Reef technology is unique within the Australian market.

“We could produce small batches in collaboration with other wineries, and while we’re 100 per cent Margaret River at the moment, there’s the opportunity for us to take parcels from other Western Australian regions. Pinot noir from Great Southern would perform really well in this process.”

There’s an obvious passion for the wine as well as the ocean surrounds, as Brad and Simon talk about what they’re building here. Simon recalls that when he told friends and colleagues that he was moving back to his native WA from Sydney to “do wine under water” the response that often came back was, “that’s nuts.” But, over time, he’s seen that change, and not least among his peers.

“You have to talk to the industry to get it off the ground and we’ve got to the point now where wineries are ringing me and saying, ‘I’ve got some shiraz, would you like to partner with us to put it in the ocean?’” 

Brad, after years of spruiking the abalone story, is measured as, one by one, he gets the key points of the Subsea vision across. But there’s a moment that’s less polished but wholly human. How did they feel when they first raised a vat and finally got to taste? “We were all sweating bricks, whether it was going to come out good,” says Brad. “But when we first tasted it on the wharf, it was like, fucking yeah! This is good.”

This article first appeared in issue #78 of Halliday magazine. Become a member to receive four issues per year, digital access to over 180,000 tasting notes from more than 4000 wineries, plus other benefits.