We're wearing gumboots and standing in the barrel room at Nautilus Estate in Marlborough.
Brett Bermingham - assistant winemaker for the Nautilus label and winemaker for the Opawa label - is using a steel "wine thief" to extract wine straight from the barrel for us to taste.
And as we sip the still cloudy wine he gives us some background on this region which has become synonymous with sauvignon blanc. As Bermingham says, no other variety has had such an impact on the market.
We're surprised to hear that this popular variety has been made for 26 years in this region. And in fact wine has been made here for 100 years.
As he puts it: "Our style is very dry. It's not heavy or over the top."
He says the aims of these free wine tours that cut out some of the "hocus pocus" around winemaking is that people can have "more of an association with the wine. You can visualise it".
Marlborough was responsible for 76 per cent of New Zealand's total wine vintage last year and 91.9 per cent of the country's sauvignon blanc, as well as chardonnay, pinot noir, riesling and pinot gris.
It has 142 wineries, 544 grape growers and 40 cellar doors but no traffic lights, which gives you an idea of how relaxing it is to drive around here.
If you're travelling from north to south, this region is the last stop on the Classic New Zealand Wine Trail, a 380km route easily recognisable by the grape vine logo you see as you drive down the heart of the country - and then take the ferry across to the South Island. It encompasses Hawke's Bay, Wairarapa, Wellington and Marlborough.
You can combine visiting wineries and fabulous restaurants such as the one where we had a bistro style lunch - Wairau River - after the tasting at Nautilus, with farmers' markets and artisan food producers.
You can also do a classic art deco tour of Napier in a 1955 Packard, boat on the Marlborough Sounds and visit the bars and museums of Wellington.
And it's not all eating and drinking - but mostly. One morning we got up early and even in the freezing cold rode bicycles through the farms and vineyards of Hawke's Bay - which has around 190km of cycle tracks - on a bike tour run by Takaro Trails.
We'd stayed at Black Barn Retreats the night before in a huge and luxurious house overlooking the river, one of 12 properties available for nightly rental. Black Barn Vineyards, which is very popular for weddings, also has a wonderful restaurant which is open for lunch and an outside amphitheatre for concerts for an audience of up to 1800 people.
It's almost sunset and Hamish Prins from Prinsy's Wine Tours drives us through the Gimblett Gravels area as the sky is turning pink over the vines. We visit Sileni and Trinity Hills for tastings and wind our way up Te Mata Peak to see magnificent views of Hawke's Bay and the Pacific Ocean. Later we tour Craggy Range Winery and eat dinner in front of the fire at its Terroir restaurant.
Prins explains that Mission Estate Winery was established in 1851 by a group of French missionaries, making Hawke's Bay the oldest wine region in NZ.
The next day we drive to the Pukaha Mount Bruce National Wildlife Centre in the Wairarapa, which is conserving rare and endangered wildlife, particularly birds. You can watch wild kaka being fed each afternoon and see Manukura, New Zealand's only white kiwi to be hatched in captivity, snuggling up in the kiwi nursery.
A little bit further down the track is the astounding Wharekauhau Lodge and Country Estate, perched on top of the rugged coast overlooking the Pacific Ocean where in the 1840s the pioneers walked a herd of sheep from Wellington. The lodge is a grand country house with gorgeous cottages that look out on this view.
Guests can tour the sheep station, including seeing shearing and sheep dogs at work, walk through ancient forests or along the coast and beaches, go fishing or just enjoy the indoor pool and the incredible meals. The property now also runs the relatively new cattle breed of Speckle Park. Many guests arrive by helicopter, which takes only 15 minutes from Wellington.
With its own vineyard, the lodge recently established the Wharekauhau Wine and Food Society and members can enjoy exclusive offers.
With a night in Wellington, we just had time to pop in to see the amazing collection of Maori cloaks at Te Papa (the Museum of New Zealand) and other exciting exhibits, before enjoying more food and wine at one of the city's many fabulous restaurants, The Ambeli.
The next morning the Interislander ferry takes us to Picton, at the top of the South Island close to the Marlborough wine region.
Bashing over the waves in a water taxi that afternoon, we head to the Bay of Many Coves Resort, on Queen Charlotte Sound, a network of sea-drowned valleys. Sometimes people doing the Queen Charlotte Track drop into the resort for a meal, such as the eight-course degustation dinner we enjoy that night.
On the last morning we spot dolphins playing in the cold waters and our trip is complete.
IF YOU GO
Getting there: With its central location to both the North and South Islands, Wellington is the perfect gateway to the Classic NZ Wine Trail.
The writer was a guest of the Classic New Zealand Wine Trail.