Bright, sparkling diamonds.

These are some of the biggest tartrate crystals I have ever seen on the underside of a cork.  Not surprising, I suppose, considering the age of this Sauvignon Blanc (SB) and the fact that it has been stored upside down in a cool cellar for the past 5 years.
Tartrate crystals, also known as wine diamonds, are a harmless, flavourless by-product of winemaking.  When tartaric acid, an acid naturally found in grapes, binds with potassium (under low temperatures) potassium bitartrate (cream of tartar) is formed.  If not removed from the wine, by a process called cold stabilisation, excess tartaric acid will solidify and form crystals when wine is chilled in a refrigerator. Voila, wine diamonds!
The bejeweled-wine, in this instance, was a Kobalt Wines 2011 Sauvignon Blanc (Knights Valley AVA).  At the grand old age of 6, this is the oldest SB I have had in a quite a while. It's not that I don't like older white wines, I just tend to drink whites when they are young and fresh. One of my favourite things to do with Thud, on visits home, is share a bottle of an older vintage Sancerre (Ladoucette Comte LaFond, an absolute favourite, springs immediately to mind).  I just don't think New World white wines age as well as those from the more traditional wine regions of the world - yet. Having said that, the Kobalt SB was a delightful wine, very food friendly and very moreish.

Oil on water.

I have recently noticed that there are a lot of Tesla electric cars in the Napa Valley.  A lot. There was a time when spotting a Tesla was a rare event, but now they are ten a penny. Yesterday, a dusty, brown Model S sneaked up on me outside the Oakville post office (those things are dangerously silent).  Then today, on my way to work, I was behind a Model S that had decided that I was going to drive up to TWWIAGE at no more than 35 mph.  God love 'em!
The shiny, navy blue Tesla of this morning was brand spanking new and, as yet, had no license plate.  In lieu of a license plate there was a card that read 'ZERO Emissions'.  Well, obviously there are zero emissions, it's an electric car. However, the power station responsible for generating the electricity to power my friend, the tortoise-like Tesla, is most definitely not pumping out zero emissions into the atmosphere: the generation of electricity is not without consequences.  That fact, unfortunately, just happens to be an inconvenient detail that most electric car owners seem to ignore. Generally, I have discovered that just ignoring, and denying, reality doesn't make it simply disappear. My musings reminded me of a story that I read in the Napa Valley Register last month.
A short road that dead-ends at the Napa River, and is soon to be developed with a 489 unit apartment village, is to be renamed.  The current name, Oil Company Road, has been deemed unsuitable for the new residential complex and so the road is to be renamed Sousa Lane West (the continuation of a small road on the other side of Soscol Avenue that heads east to the Silverado Trail).  And why is someone bothering to rename Oil Company Road?  A spokesman, when asked this question, said, "We chose to change it because of the confusion of 'oil company' with 'oil cans'; it carried a derogatory feeling to it." What? How fragile are the psyches of the folks who will eventually inhabit these new apartments? Apparently, history has to be forgotten, or worse rewritten, to save these apartment dwellers from the perceived horrors that are fossil fuels.
In the 1890s, this part of Napa - along the river, but on the opposite bank to downtown - was a dockyard area mainly occupied by gasoline wholesalers who when the demand for petroleum grew supplied that demand.  The flourishing industries that relied on the gasoline wholesalers were tanneries, mills, cream of tartar factories (there were a lot of grapes here, even then) and, of course, the power plants that supplied the electricity to these industries.  The same electricity that powers the myriad of Tesla motor cars that are tooting around the Napa Valley today.
I am glad that I got a photograph of the Oil Company Road sign before it is removed, and before the powers that be rewrite Napa history to the absolute detriment of future generations of Napa Valley residents.

Chill out!

Chilled down to 27F, this 3000+ gallon stainless steel tank full of delicious Sauvignon blanc is undergoing cold stabilisation. I love passing through the tank room at the winery whilst this process is underway. This particular winery operation never ceases to amaze me as I always find it interesting to see the gunk (technical term), collect in the bottom of the 375ml sample bottle as the fining agents work their magic, leaving the beautifully clear wine above. Strange, but I suddenly feel thirsty.

Cold stabilisation.

Cold stabilisation is an important step in the process of winemaking. It is the means by which the excess tartaric acid in wine is precipitated out as potassium-bitartrate salt. Tartaric acid is very soluble in wine, it's less soluble mono-salt, potassium-bitartrate preciptates out in an effect known as 'salting-out'. This lowers the total acidity, and alters the final pH, of the wine.
Now some people may like wine diamonds in their glass, but most consumers prefer a little less crunch in their wine beverage of choice. The purpose of potassium-bitartrate stabilisation is to prevent the crystallisation of the tartrate in the bottle.
This is a 3 week long operation at the winery with the tanks being frozen down to 27F, resulting in a good half inch of ice on the outside of the stainless steel. Additions, in ppm, of isinglass and bentonite aid in the fining process which produce a beautifully clear wine that is however still rich in ML bacteria...on to the filter.
On a 90F day, like it was yesterday, I try to find any excuse to be in the tank room so that I can give a frozen tank a hug...even if it does contain Chardonnay!