What is greywacke, and why would a winery in New Zealand give itself that name?
First, greywacke is a sandstone that contains a significant amount of silt and/or clay. According to the University of Auckland in New Zealand, greywacke “…comprises a large percentage of the basement rock of New Zealand, and so is an important rock type throughout the country. Because it has been subjected to significant amounts of tectonic movement over a long period of time (some New Zealand greywacke is over 300 million years old), greywacke is commonly extremely deformed, fractured, and veined.”
The winery owners, Kevin and Kimberley Judd, adopted the name Greywacke for their first Marlborough vineyard located in Rapaura, named in recognition of the high prevalence of rounded greywacke river stones in the soils of the vineyard. Kevin Judd was born in England but raised in Australia before he moved to New Zealand in 1983 where he worked for Selaks, and later was the founding winemaker at Cloudy Bay, which we should all recognize. He and Kimberley started Greywacke in 2009. The Greywacke portfolio is primarily based on two varieties, Sauvignon Blanc and Pinot Noir.
I received a bottle of the Greywacke Marlborough Sauvignon Blanc to taste recently. I read up on how this wine was produced. From Greywacke, “The grapes were harvested largely by machine during cool (often cold) night-time conditions picked into half-tonne bins, which were tipped directly into a tank press and lightly pressed. The resulting juice was cold-settled prior to fermentation in stainless steel, primarily using cultured yeast for cool, slow fermentation. A portion was also allowed to undergo spontaneous indigenous yeast fermentation. All individual vineyard batches were left on lees and kept separate until late July, when the blend was assembled.”
How does that translate into the wine I tasted? Let’s find out.
My Tasting Notes
Greywacke Marlborough Sauvignon Blanc 2018 (BC$30.99) – A medium medium straw colour in the glass. It has a medium intensity nose that changed over the 10 minutes that I was tasting it. At the first sip, you get a mix of honey, peach, yellow grapefruit and rind and a hint of flint. With air the aroma changes with the peach fading and you get jalapeno pepper. On the palate, this wine is higher with higher acidity, but still has roundness to it, and is very mouth-filling. You do get some acidic prickle from this wine but it is light and gives texture to the wine. Fresh flavours of citrus, in particular grapefruit and it’s rind, a touch of blackcurrant leaf and peach. Again with a few minutes of air you get jalapeno pepper and honey flavours. Toward the finish, you get a mix of steeliness and salty minerality. It does finish with blackcurrant leaf, sweet stone fruit, citrus, and honey or marmalade.
A longer decant did not make the wine any more approachable. On the nose there was now guava and the jalapeno pepper aroma decreased. On the palate, the wine became softer and smoother, crisp apple flavour was added and no jalapeno pepper was perceived. So in my opinion, pouring this wine and giving it a few minutes to decant in your glass is the perfect amount of time before enjoying it.
This wine overall is more restrained than you would get from other New Zealand Sauvignon Blanc wines. It is more elegant and nuanced.
Rating: 
Give this wine a few minutes to decant before drinking and you will enjoy a wine with a nice mix of honey, grapefruit and jalapeno pepper aromas and flavours. Quite mouth-filling and round, with a light acidic prickle.
