Katherine Cole on Black Chardonnay

My husband forwarded me this link Meet Black Chardonnay written by Katherine Cole (author of the book Voodoo Vintners). Both of us read it with a lot of interest. Since we vinified our first small batch of Chardonnay this year, we know that turning Chardonnay grapes into wine can be tricky if we want our wine to age well.
The question is: reductive or oxidative strategy?
Professor Denis Dubourdieu and Dr. Valérie Lavigne researched the recent propensity of Chardonnay in Burgundy to succumb to premature oxidation and I wrote about their research in a blogpost that I called How to Prevent Premox in White Wines.
Answer: Keep it reductive. So consequently, winemakers struggled mightily to keep oxygen out of their winemaking regime. Press gently, keep oxygen away from the must!

Now, however, Katherine Cole writes about the black Chardonnay movement. This is NOT the "benign oxidation" browning, that our class reached a consensus on, as a good thing, in our online U.C. Davis course while reading and discussing the seminal article written by V. Schneider called Must Hyperoxidation: A Review.
In a technique used in Burgundy some 60, 70 or 80 years ago on Chardonnay, you must crush, grind, shred and hard press the resultant pulp in order to get this black must. This heavy handed treatment removes those phenols that cause astringency and bitterness as a precipitate, leaving the juice clear. It also removes phenols that become prone to browning through oxidation.
This technique is being practiced by winemakers in Oregon with amazing results. My husband looked up OO Wines that is using this methodology on their Chardonnay, but it cost $65.00, a little too rich for our tastes. I did try to convince him that we needed to purchase a bottle for "research purposes".

References:
1. Katherine, Cole, Meet Black Chardonnay, SevenFiftyDaily, August 3, 2017.
2. V. Schneider, Must Hyperoxidation: A Review, Am. J. Enol. Vitic., Vol. 49, No. 1, 1998.

2014 Paumanok Chenin Blanc Minimalist and 2015 Millton Chenin Blanc

Recently, we had our friends over for oysters from Harmony Sea Farm. These oysters are grown right in our backyard by Garrett and Sally Timmons. We got to taste their first harvest!

There is nothing better to pair with oysters than Chenin Blanc and we had 2 exquisite examples. We began with the 2014 Paumanok Chenin Blanc Minimalist. The back of the label is where you will find the vintage information as well as vinification information. Only unblemished, select clusters of Chenin Blanc from the vineyard planted in 1982 (35 year old vines!) were hand harvested and whole cluster pressed. Spontaneous fermentation began in stainless steel barrels and the wine was aged for 6 months. There were only 84 cases of 2014 Minimalist Chenin Blanc made. We heard an interesting story from Charles Massoud when we visited the winery recently. Charles mentioned that the Chenin Blanc was initially planted to blend with Chardonnay. But, Chenin Blanc, (as we found out) is one of those white varietals that doesn't really play well with other varietals in a blend and why would anyone want to dilute Chenin Blanc with Chardonnay!

The next wine that we opened was a 2015 Millton Chenin Blanc that our friends brought home from their sojourn to New Zealand. The Paumanok and the Millton could not have been more different on the palate! We immediately picked out the oak notes on the palate, slightly muted fruit and acidity and overall creamier mouthfeel. This Chenin Blanc was vinified in a totally different way from the Paumanok Chenin Blanc in demi-muids (large 600 litre oak barrels) as well as in stainless steel tanks. The notes from the winemaker mentions that up to four selections are made in the vineyard. The grapes are hand harvested, destemmed and crushed and the juice is allowed to settle. The fine sediment is kept as nutrients for fermentation. This wine had a total acidity (TA) of 7.5 g/L, pH of 3.33, alcohol content, 12.5% and residual sugar measuring 6.2 g/L.
Both wines were deliciously different and both were very much appreciated with the oysters. As we moved on to our second course of salad with bread and cheeses, the wines paired well with the cheeses too, providing for a wonderful degustation with friends!

Happy Thanksgiving: Something to Gnaw On

Here is a pre-Thanksgiving blogpost. I am currently reading a review called Origins of Grape and Wine Aroma. Part 1. Chemical Components and Viticultural Impacts that appeared in 2014 in the American Journal of Enology and Viticulture. It is 24 pages long so, I've been plodding along and trying to digest the review in small bites.
This morning, I came upon a paragraph that is almost incomprehensible by a lay person. I reproduce it below:
          Methional concentrations increase in white wines exposed to           elevated temperatures and oxygen. Under these conditions, the           compound is produced via a Strecker degradation of methionine to           methional in the presence of a dicarbonyl compound or via direct           peroxidation of methionol.
Whaaaaat?
Fortunately, my husband who is a chemist was sitting across from me, drinking his morning coffee, and I asked him do you know what a "Strecker degredation" is? He said, "sure, is that an oxidation?" (Close but no cigar!) Back in the days of taking organic chemistry, there were certain "name reactions" that one could memorize. So, here is my take on what the above paragraph translates into in organic chemistry terms.

So, the diagram above can be captioned: In the presence of a compound with 2 carbonyl groups, the amino acid methionine can react with one of the carbonyl groups forming an unstable intermediate. With the incorporation of 2 molecules of water, the unstable intermediate results in the formation of ammonia, carbon dioxide and methional.
What is wrong with having methional in white wine? The smell for one thing is of "cooked vegetables". Methional is also thermally unstable and undergoes a retro-Michael reaction that leads to the wet dog or wet wool smell in wine that comes from methyl mercaptan and acrolein.
Here is hoping that your Thanksgiving is a wonderful one with wines innocent of Strecker degradation and retro-Michael products. Cheers!
References:
1. Wil Konings, ‎Otto Kuipers, ‎O.P. Kuipers, Lactic Acid Bacteria: Genetics, Metabolism and Applications, 1999, pg. 250.

New Tab: White Winemaking

Today, I spent a few hours collating all of the blogposts on "white winemaking" and created a new tab:

Under that tab, you can find all of the postings related to "white winemaking":
How Many Grapes Does It Take to Make a Bottle of Wine
Making White Wine
White Wine Production Theory and Practice
To Inoculate or Not, that is the Question
Skin Contact for White Wines
Reductive Regime vs Oxidative Regime for White Wine Making
Rehydrating and Tempering Yeast
Benefits of Low Temperature Fermentation
Sur Lie Aging of Wine
Diacetyl Formation

White Winemaking Chemistry
Hyperoxidation Revisited
How to Prevent Premox in White Wines
Chemical Marker Sotolon Found in Premox Wines
Strategies to Manage Dissolved Oxygen
Post-Bottling Aroma Defects

I will keep adding to this tab as necessary. I hope it is useful to you!