It's a technique pioneered by New Zealand winemaker Dominic Maxwell at Greystone Wines in the South Island's North Canterbury area.

Dom and his team have experimented with vineyard fermentations since 2012.

"Once grapes come off the vine and into the winery, they're exposed to new yeast from within the winery. We wanted to eliminate exposure to foreign yeast and ensure only native yeasts from our vineyard are involved in the fermentation," he explains.

The inaugural 500-bottle 2016 Vineyard Ferment Pinot Noir was released in 2018 and a 2017 version has followed.

In Australia, Greystone wines can be found in independent wine stores, including The Lambton Fridge, and for visitors to NZ at the Waipara cellar door.

The Greystone story began with UK-based banker Peter Thomas developing a love of French pinot noir burgundies and looking for somewhere to produce such wines in his New Zealand homeland. In 2000 he and his brother Bruce found what they sought on an old sheep farm north of Christchurch.

In 2004 viticulturist Nick Gill planted vines on the north-facing limestone hills sloping down to clay and recruited Dom Maxwell to help.

Dom initially studied for a Lincoln University commerce degree, during which he worked in a market garden. That sparked an interest in wine, which was heightened when he and his wife Nadia took off overseas, working in London and haunting wine shops and touring European vineyard areas.

Back in NZ he got the Greystone job and launched into a Lincoln viticulture and oenology degree, which has led to his present post as winemaker of Greystone and its associated Muddy Water brand. Greystone's first wine was produced in 2008 and in 2014 a switch to organic viticulture began, culminating now in 100 per cent organic certification.

Since then it's emerged as one of NZ's top producers with its 2016 pinot gris gaining a place in Britain's Decanter magazine's Most Exciting Wines of 2017, winning the 2018 New Zealand Winery of the Year and seeing Dom Maxwell crowned Gourmet Traveller's 2018 NZ Winemaker of the Year.

Today Dom, Nick Gill, as founding viticulturist and general manager, and Australian-born Nik Mavormatis, as general sales and marketing, are Greystone's key three.

Nik has strong Hunter links. His great grandfather owned a Greek café in Cessnock in the 1930s. He is an annual visitor to his uncle and aunt in Raymond Terrace.

THIS fresh, crisp Greystone 2016 Sea Star Riesling and other Greystone wines are available at The Lambton Fridge. The wine is green-tinted straw and has honeysuckle scents and ruby grapefruit front-palate flavour. The middle palate shows pear, lime zest and gunmetal characters and the finish slatey acid.

PRICE: $29.95.

DRINK WITH: smoked salmon pasta.

AGEING: six years.

RATING: 5 stars

THE Greystone 2017 Chardonnay is a big, richly flavoured, 13 per cent-alcohol white with brassy hues and scents of mango and crushed almond. The front palate brings forth intense golden peach flavour and the middle palate features melon, lemon curd, brioche and cashew oak characters. Flinty acid refreshes at the finish.

PRICE: $47.95.

DRINK WITH: coriander and coconut crabcakes.

AGEING: five years.

RATING: 4 5 stars

WITH 13.5 per cent alcohol and a portion from vineyard-fermented must, this Greystone 2016 Pinot Noir is bright garnet and has gamey aromas. Ripe raspberry flavour shows on the front palate, mulberry, spice, spearmint, cloves and savoury oak chime in on the middle palate and the finish has earthy tannins.

PRICE: $47.95.

DRINK WITH: cherry-glazed duck with pear and rocket salad.

AGEING: eight years

RATING: 4 5 stars