Marlborough winemakers are clamping down on the country's most iconic brand, with measures to better control what happens between grape and glass.
A new certification has now been trademarked around the world, similar to what the French have done with Champagne, Burgundy and Beaujolais.
Sauvignon Blanc accounts for 86 per cent of the country's total wine exports.
Nautilus Estate Winemaker Clive Jones says they know they've "got onto a good thing".
"It's a phenomenon how it's become internationally recognised in such a short period of time," he says.
But with that huge global demand, producers recognise their "hard-earned reputation could be put at risk".
"Fundamentally, if you make wine in New Zealand and you put the word 'Marlborough' on the label, then only 85 per cent of the wine must come from Marlborough by law," explains Wine Writer Michael Cooper.
A group of wine makers established Appellation Marlborough Wine in 2018, a certification that guarantees certain standards have been met.
AMW Marketing Manager Amanda McRae says the wine has to be 100 per cent Marlborough fruit, "so all grown in a Marlborough vineyard", with 85 per cent of it needing to be Sauvignon grapes.
The wine has to be bottled here in New Zealand and come from vineyards certified by Sustainable Winegrowing New Zealand and cropped within certain parameters.
So far there are 49 licensed members and over 90 certified wines. The focus is Sauvignon Blanc but the appellation may eventually extend to other varieties.
Branding expert and University of Auckland Professor Rod Brodie says the move is a step towards securing New Zealand's wine identity into the future.
"It's sort of like a honeymoon that never ends, and when I go to Australia or other parts of the world and see the problems they're having with their industry, somehow our heritage, providence, things like that, have meant that we seem to be able to do things right," he says.
He says there now needs to be "further dialogue" about developing what are "quite complex narratives about wine in New Zealand".
The certification's now trademarked globally, including the US, Europe and Asia.
Mr Cooper says wine commentators and wine enthusiasts overseas were already "taking note" and "you'd expect it will lead to a change in buying behaviour".