What are wine diamonds?
Have you ever looked at a bottle or glass of Gibbston Valley wine and asked yourself, what are those little specs that have accumulated at the bottom of my bottle? The answer is satisfyingly simple.
Diamonds in the Rough
The crystalline deposit you discovered is not at all unusual. In fact, it’s evidence that you’re drinking wine that hasn’t been subject to undue manipulation, something we strive for at Gibbston Valley Winery. Importantly, those deposits are absolutely harmless.
The collection of crystals are precipitations of potassium and tartaric acid, both of which are naturally-occurring elements in the grapes. They’re known as tartrates, or euphemistically, “wine diamonds.”
Tartrates accumulate in wine with time, precipitating out slowly, combining with colour molecules and tannins to form the spider-like chains that you see in your glass.
Sometimes, before the wine is bottled, a winery will chill a finished wine down in tank, to -4 degrees Celcius for a couple of weeks, in order to initiate tartrate precipitation, a process known as cold stabilisation. Then, the wine will be filtered to remove the tartrates.
This process is one we choose not to subject our wines to at Gibbston Valley. We would rather our wines come to you in an unfiltered state, as close as possible to the natural expression of grape variety, place and vintage as we can provide. Many quality focused producers are of the same mind – especially in the Pinot Noir world.
A Sense of Place
Method is everything in winemaking. Our approach to the hallowed trade is a testament to our relationship with tradition and the land. At Gibbston Valley, we are blessed to have exceptional land and fruit.
Processing fruit from our Homeblock as well as from other plots in Gibbston and Bendigo (Sub-Regions of Central Otago) in an outdoor, open-air winery reaffirms that connection with the elements.
Our proximity to the extreme environment is a constant reminder of what our vines must endure to produce the small clusters of deeply flavoured fruit that we love to work with. Coupled with the unique terrain, soil composition and climate (or terroir, pronounced tɛrˈwɑ), it is respect for the fruit that inspires our winemakers.
In comparison to the 12.2 tonnes per hectare yield of Sauvignon Blanc harvested in 2013 in the nearby Marlborough winemaking region, our Pinot Noir vineyards average 6 tonnes per hectare—a radical difference in fruit relative to the labour that goes into harvesting and making wine.
With such a beautiful selection of grapes, why muck it up? That is why our winemakers avoid methods like cold stabalisation as they strive for purity in process. With all this personality, it’s important that we remember that wine, of course, is not skin-deep.
As each winemaker and winemaking team shape their approach, there is a sense of identity that comes to form. Changes are inevitable, but that relationship is evident as each vintage finds its place on the wine-racks of history, undeniably different and special in its own right.
There's no right or wrong in this craft, but with the current levels of global wine production, it’s important to stand out—for the right reasons.
Next time you find tartrates in your glass, consider them a reminder that our practices are more artisanal than commercial. They’re our reassurance to you that we strive for minimal intervention in our winemaking practices to handcraft Central Otago-style varietals in their purest form.
Enjoy the wine, and let the diamonds shine!