Chardonnay: Grape Derived Compounds

My husband and I are interested in how best to vinify our Chardonnay. This year, we have 2 small batches of Chardonnay that we fermented in stainless steel kegs and in one keg, we added malolatic bacteria to carry out the conversion of malic to lactic acid.
Since Chardonnay is a neutral grape variety, it can be vinified in a variety of ways in order to affect its flavor profile. A few techniques that are employed include:

• skin maceration
• barrel and/or stainless steel fermentation
• selected or indigenous yeasts
• malolactic fermentation
• aging in barrels with or without lees

I came across a really good article published in 2014, called Factors Influencing the Aroma Composition of Chardonnay Wines. In this article, the authors breakdown the aroma and flavor compounds and precursors derived from (1) grapes, (2) fermentation, and (3) aging that contributed to the various styles achievable when making Chardonnay.

So how do you like your Chardonnay? Oaked, buttery, fruity, searingly acidic, with so many styles to choose from, what defines quality in a Chardonnay? Although Chardonnay is a neutral white variety, some of the chemical compounds that contribute to a particular Chardonnay style can be found in the grape and can determine "quality" as well as "typicity". So, what are these compounds?

The above illustration shows compounds that are in grape berries or, more often, have precursors which are present in berries that are modified during fermentation or aging.
The compounds 1,1,6-trimethyl-1,2-dihydro-naphthalene (TDN), β-damascenone, and 3-oxo-α-ionol also known as C13-norisoprenoids, are formed during berry ripening from carotenoids in the grapes. β-damascenone and linalool are compounds that can be used to identify a young wine as a Chardonnay. The "lemon balm" aroma can be attributed to the presence of β-damascenone at perceptible concentrations. At higher concentrations, β-damascenone smells of “apple”, “rose”, and “honey”.
Since wine is a living entity, evolving and changing as time passes, these fresh fruity notes can change with age. Aging of Chardonnay brought about a loss of the fruity and floral characters associated with a young wine. The concentrations of β-damascenone and linalool declined with wine age. The loss of the acetate esters, acid catalyzed hyrolysis of ethyl esters of short-chain fatty acids, and the acid-catalyzed rearrangement linalool into less aromatically intense compounds such as α-terpineol contributed to the loss of fruity and floral notes.
My next few blogs will deal with fermentation and aging derived compounds and their impact on the aroma and flavor profile of Chardonnay.
Thanks for tuning in!
References:
1. Gambetta JM, Bastian SEP, Cozzolino D and Jeffery DW., Factors influencing the aroma composition of Chardonnay wines, 2014, J Agric Food Chem 62:6512–6534.
Illustration created from Table 2. Characteristics of Grape-Derived Odorants Important to Chardonnay Wine Typicity, pg. 6513 of the reference above.
2. Joanna M. Gambetta, Leigh M. Schmidtke, Jiaming Wang, Daniel Cozzolino, Susan E.P. Bastian, David W. Jeffery, Relating Expert Quality Ratings of Australian Chardonnay Wines to Volatile Composition and Production Method American Journal of Enology and Viticulture Jan 2017, 68 (1) 39-48; DOI: 10.5344/ajev.2016.16058

Gabriel-Glas Stemware

I inadvertantly broke our Bordeaux glass, (okay I will admit to a certain amount of klutziness) and thought that we only had one left. My husband seized upon this unfortunate glass shortage to look into procuring the universal wine glass. Currently, our wine glass cupboard is full of wine glasses for different wines: champagne, Burgundy, and Bordeaux glasses. We also have stemless glasses. The claim of this universal glass is that it is a wine glass for all wines.
If you were to get a glass for every type of drink it can be endless: Burgundy, Pinot Noir, large Bordeaux, Cabernet Sauvignon, standard red, dessert wine, white wine, Chardonnay, Port, Madeira, standard sweet, Sherry, Sauternes, Alsace, Hock, tumbler, etc. and the reason would be that a specific style of stemware is most suited to showcase that particular wine's attributes.

Not only are there a number of different wine glasses you can choose from, there are countless articles written on how to choose the appropriate stemware. In looking for a universal wine glass, I came upon an article at Kitchn called The One and Only Wine Glass You Need According to Sommeliers, in it, the sommeliers recommended the Zalto. We purchased the standard Gabriel-Glas.
What I like about this stemware is that it is noticeably lighter than our other glasses. I like the shape of it as well. At this point, I haven't reached any conclusions as there is more research and comparisons to do, requiring more drinking of wine!
Reference:
1. Photo attribution from: Wine Folly, Types of Wine Glasses.
2. Kitchn, The One and Only Wine Glass You Need According to Sommeliers.
3. Gabriel-Glas.

Checking for Titratable Acids

Recently, my husband ordered a paper chromatography kit for checking the titratable acids in our wine. We did this because we want to conduct a malolactic fermentation (MLF) on our Chardonnay. So, we needed to have some way of "seeing" what acids are in our wine. This kit comes with standards for malic acid, lactic acid and tartaric acid. Using a special solvent that is provided with the kit, paper chromatography allows the separation of these acids. It is a qualitative, but somewhat semi-quantitative means of ascertaining what acids are present in the solution being tested (wine).
This is rather hilarious for me because my husband has a Ph.D. in Chemistry. So, he had to dust off some of the cob webs in his mind to harken back to a time (General Chemistry 101 and the associated lab), where he actually did a paper chromatography experiment.

The paper that is provided is called the "stationary phase" and the solvent is the "mobile phase". As the mobile phase is being drawn up the stationary phase by capillary action, the compounds (wine samples) in the stationary phase get separated.
These are the results that we got for our wines:

The samples are labeled on the x-axis and the y-axis shows how the tartaric, malic, and lactic acids separated from the various samples. Based on this method, it appears that Chenin-7 contains very little, if any lactic acid.
Since we are conducting our malolactic fermentation on Chard-2 (Chardonnay-2), we will keep this chromatogram to refer to as our MLF progresses.

2010 Chateau du Trignon Vacqueyras

My husband bought this Vacqueyras at our local package store and we had it with a delicious red sauce that our friend gave us.
Vacqueyras is located in the Southern Rhone and in the case of this Chateau du Trignon, is made with Syrah grapes.
The wine was dark magenta in color and the tannins had smoothed out since this wine is already 7 years in the making. I don't recall any tobacco notes, nor do I recall any fruit notes in the wine. To me, this tasted very dry but not astringent and was a perfect complement to a hearty red sauce. The best part of this 7 year old Syrah is that you can purchase it for less than $20.00 and that makes it a very good value in my book!
For this wine and other wines under $20.00, look under this tab:
Wines Under $20

Helpful Conversions for Small Lots

When we first started making our Chenin Blanc, we counted our clusters and determined the number of pounds and then the number of gallons of juice we had. This doesn't take into account the losses that were incurred with each racking. Our first vintage consisted of approximately 355 clusters that weighed 65 pounds and produced about 5 gallons of juice. From the 5 gallons of juice, we produced twelve 750 mL bottles and nineteen 350 mL bottles that equaled 15.65L or 4.14 gallons.
It's a little difficult dealing with such small numbers. Last year, we had 1000 clusters of Chenin Blanc that weighed 100 pounds and turned into 12 gallons of juice from which we bottled one case of 750 mL and two cases of 375 mL plus 3 bottles. We totally had to pour down the drain approximately 4 gallons of juice that we messed up, so we ended up bottling about 4.76 gallons of wine.
We have been going to get our yeast supplies from Hartford and found two charts of helpful conversions for small lots that I took a photo of:

Those conversion charts are very helpful, so I reproduced it so that I could refer to it:

I was wondering why the pounds to gallons chart included what appeared to be an odd 36 pounds conversion.
When we went to get our yeast, the loading dock was full of grapes in crates. There were also crates of Barbera and since we are growing Barbera, I had to take a picture of the crates.
When I got home, I noticed that each crate was 36 pounds. So, if someone bought one crate of Barbera they could make 2.5 gallons of wine. To buy a ton of grapes, one would have to purchase approximately 56 crates!

Chenin Pét-Nat

What do scientists do? The answer is "experiment". This year, since our harvest exceeded our expectations, we have a few small kegs to experiment with. My husband is interested in making a Pét-Nat wine from one of our 10-liter kegs of Chenin Blanc.
The article, What Is Pét-Nat Wine? An Ancient Winemaking Style on the Rise on Bloomberg Pursuits online, provides a very good explanation for what this style of wine is. The article explained that the term "Pét-Nat" can be traced back to sometime in the ’90s in France’s Loire Valley when two natural winemakers, Thierry Puzelat and Christian Chaussard, began rediscovering the method of producing sparkling wines in this style.
The pét-nat style is also referred to as méthode ancestrale, meaning the wine is bottled before primary fermentation is finished, without the addition of secondary yeasts or sugars. This method produces a simpler, more rustic sparkler than Champagne, one that is traditionally cloudy, unfiltered, and often bottled with a crown cap (like a beer) rather than a cork.
I'll try to chronicle our experiment in pét-nat. Please watch this site.

VIN 13

We have been busy cold settling our Chenin Blanc juice in a 50 degree temperature controlled settling chamber, in order to rid the juice of most of the large particulate matter, the gross lees and then racking it to a clean keg to warm up to fermentation temperature, 62 degrees F. This is a tricky procedure because the juice must be racked out of one chamber, the used keg is then removed from the chamber and then the juice is pushed by nitrogen into a fresh keg in a warmer fermentation chamber. Since we only have 3 temperature controlled chambers (freezers), we are now down to putting the racked juice into the same fermentation chamber to warm up.
For all of our previous fermentations, we have used the yeast called QA23, based on a South African study called Effect Of Yeast Strain And Lees Contact On Chenin Blanc Wine Quality, in the on line journal WineLand. This article focussed on the comparison between the following four yeast strains VIN 13, N 96, QA 23 and NT 116 based on:

• successful completion of fermentation
• ester production
• formation of lees character
• overall wine quality

The study found that:

• Yeast strains QA 23, N 96, VIN 13 and NT 116 produced the highest levels of acetate esters and corresponding fruitiness
• Yeast strain QA 23 produced the most fruitiness, lees character and highest overall wine quality
• Yeast strain N 96 produced wines with slightly more body than the other yeast strains
• All yeast strains exhibited low levels of sulphury flavours due to aeration of the lees directly after fermentation
• For those yeast strains that were on lees for five months, nuances of bread, sparkling wine, citrus and buttery flavours were observed

In 2015, the first year that we used QA23, we let the fermentation go completely to dryness, which we later learned was one of the characteristics of this yeast. For the majority of our fermentation, we are using QA23, but we thought it might be instructive to try another yeast, so we chose VIN 13. We are fermenting the juice with VIN 13 in one of our 15 gallon kegs. In rehydrating and tempering the yeast, we thought that the initial foam it produced was darker in color and much finer.

Right now, we are waiting for fermentation initiation.
Reference:
1. Johann Marais and Neil Jolly, Oenology research, Winetech TechnicalEffect Of Yeast Strain And Lees Contact On Chenin Blanc Wine Quality, Oenology research, Winetech Technical, 1 September 2005.
2. Sctt Lab, VIN 13 Technical Sheet.

Harvest Step 3: Grape Stomping

After Grape Cleaning comes the most fun part of the day. You can channel your inner Lucy Ricardo (oh--you are too young to know Lucy Ricardo of "I Love Lucy"?). Regardless, the experience is rather mirthful and I can promise you that your feet never felt anything like this before.
The movie below is a compilation of photos taken from the Chardonnay Harvest that occurred on September 23, the Chenin Blanc harvest on October 6 and 7, and the final stomping on October 8, stitched together to make one movie that features all of our friends who came to help.

A last stomping was held on Sunday, October 8. There was a last bit (okay--a large bit) of grape cleaning to do and then the final stomping of the 2017 harvest. The stomping had to be timed as rain showers came early in the morning and then disappeared in the early afternoon. Our last stomper was Hannah, everyone else was rather stomped out. I dare you to not clap your hands, stomp your feet and otherwise have a happy body when stomping grapes to the Theme from Zorba the Greek:

I'll end this post with one final photo:

It's kind of an enigmatic photo. What is it, you ask? It is the imprint of our friend's hands on our home's vinyl siding! Opa!

Harvest Step 2: Grape Cleaning Bee

First, the grapes had to be brought into our basement away from other real bees that might cause discomfort for our cleaning crew.
Imagine that you are in Burgundy and bringing the harvest into the cave. It could be a dark, musty area perhaps festooned with cob webs and mold. Or, it could be a bright florescent light environment with plastic chairs to do the task of grape cleaning in relative comfort.

Dictionary.com defines the term "bee" as derived from the Old English bēn meaning “a prayer, a favor.” By the late eighteenth century, bee had become commonly associated with the British dialect form, been or bean, referring to the joining of neighbors to work on a single activity to help a neighbor in need: sewing bee, quilting bee, etc. grape cleaning bee.
Little did our village cru know that the next step in our harvest process was something called the tweezer grape cleaning bee. Think of women (and equal opportunity for men) sitting around a circle with a grape cluster in hand, cleaning out the bad and yellow jacket afflicted grapes. It seemed as if everyone had their smart phones on mute and was focussed on the task of cleaning the grapes.

When all of the grapes were cleaned, they were either stomped or put into cold storage in our neighbor's scallop hauling truck.

Next blogpost will cover grape stomping. Come back and check it out!

Village Cru(Crew)

On October 6 and October 7, we harvested our Chenin Blanc. One of my friends said that "it takes a village" to make a wine and I concur. First, it takes a Village Cru to harvest the grapes. Although we had an order of magnitude more grapes this year than last, it still only took about 1 hour on Friday and 1 hour of Saturday to harvest our entire crop. For our Chenin Blanc, we like to start as early as humanely possible so that we are starting with cool grapes that will have a chance to retain as much of their aromatics as possible. We have four friends who have designated themselves as "Team Long Pond" who came with head lamps on to unclip the netting so that the harvest could go smoothly.
Bob (Team Long Pond) was our designated tractor driver.

Here is our village cru in action:

Here is the harvest bounty on the truck ready for the crush pad:

Here is a photo of the Village Cru:

Here is a photo of our Premier Cru, Team Long Pond:

Next blogpost will cover the crush pad and beyond.

Summary of Our Chenin Blanc Harvest

The harvest of our Chenin Blanc occurred over a few days. It began on September 29th with a small harvest of what we thought were the most yellow jacket afflicted clusters. On October 5, we harvested the grapes that were in wedding bags and scattered in the Chenin Blanc rows. Our major harvest dates occurred on October 6 and 7. For that, we sent out a message to our friends to come to the aid of the harvest. This was to harvest the Chenin Blanc in the netted rows. The number of lugs reflect the number of cleaned lugs. We have an approximation that equates 3 cleaned lugs to 50 pounds so we can extrapolate that we had approximately 1100 pounds of grapes that yielded 97 gallons of wine.
Here is a tabular summary:

DATE	#LUGS	#GALLONS
September 29, 2017	9	10
October 5, 2017	7-1/2	14
October 6, 2017	9-1/2	14
October 7, 2017	19	30
October 8, 2017	22	29

Our harvest exceeded all of our wildest expectations and for that, we are grateful to our dedicated friends who came to help us pick the grapes. Providing more details in the blogposts to follow.

Chenin Blanc Harvest

The harvest moon rose the night before the first earnest picking of our Chenin Blanc harvest. Our friends, who are there with us doing the most boring jobs in the vineyard came at 6:30 a.m. and started unclipping the netting in preparation for the 7:30 crew. We picked 4 rows of Chenin Blanc that yielded 20 lugs of grapes.
The next step in our process was to bring the lugs to our home for crushing aka foot stomping! Here are photos of first time foot stompers. I say, "Happy foot stompers make great wine!"

Before getting into the stomping tub, one must put on food grade safe booties:

What I don't show is that we take all of the clusters and manually remove the bad grapes using tweezers. We were able to clean 6 lugs of grapes and combined it with 3-1/2 lugs that were cleaned and store in our neighbor's scallop freezer transport truck. The stomping of the grapes from these 9-1/2 lugs yielded 16 gallons of juice. All of this work was done by 11 a.m.
Here is a photo of our picking and stomping crew, minus two of our early net unclippers.

Harvest Moon

Last night was the harvest moon. I knew about it but having helped my husband transfer our cold settled Chenin Blanc juice into the fermentation freezer at 9 p.m. I forgot all about it. This morning, as I was getting some muffins ready for our picking crew, I saw the full moon in the western sky and took a photo of it. I know it is not a high resolution photo but, it's what I can do.
According to Earth and Sky, the harvest moon is the full moon closest to the September equinox, and full moon comes at the instant when the moon is 180^o from the sun in ecliptic – or celestial – longitude.
National Geographic also says this harvest moon on Thursday night marks the closest full moon to the fall equinox. The last time the harvest moon occurred in October was in 2009 and the next one will be in 2020.
What does that mean? For us, in Connecticut, this instant of full moon came on October 5th at 2:40 p.m. Eastern Daylight Time.
This is so appropriate for us because this year, our Chenin Blanc harvest (not counting one we did on September 29th) began yesterday. We will harvest another small bolus of grapes today but the majority of the harvest will be on Saturday.

D47 Yeast Rehydration

On September 30, in order to kick off our Chardonnay fermentation we rehydrated D47 and tempered it with our Chardonnay to 70 degrees before inoculation. This is not the yeast that we use for our Chenin Blanc fermentation, which is QA23. We thought that the D47 became a bit more frothy than the QA23.

We inoculated the Chardonnay that we now have in two 5 gallon kegs (labeled Chardonnay-1 and Chardonnay-2) around 2:40 p.m. on September 30. When we checked on October 2 at 10 a.m. fermentation had begun, Here is a video of it:

Kicking Off Chardonnay Fermentation

On Saturday, September 23, we harvested our Chardonnay. We had a very small harvest of Chardonnay and we are still trying to fine tune our process procedures. One of the parameters was how to keep our juice from turning brown, the sign of oxidation of the phenolic compounds in the grape. A step we added to our procedure was to take one teaspoon of potassium metabisulfite and dissolve it into 1 gallon of distilled water and put a portion of this solution into a spritzer. When we got ready to stomp on the mash bag, our spritzer-in-chief, Barry,

would spritz the solution onto the mash bag. With just this minor tweak, the juice remained a green color as it went into the carboy.
On September 27, we put the cold settled juice, pictured above into two 5 gallon tanks to warm up to 60 degrees F for the next phase of our process. The color of the Chardonnay juice was much clearer by comparison to the Auxerrois juice.
On September 28, we took 40 mL from each of the two 5 gallon kegs, labeled Chardonnay-1 and Chardonnay-2, to run some tests.

Here are the results:
          Chardonnay-1
          Brix = 19
          pH = 3.0
          TA = 9 g/L
          SO₂ = 50 ppm

          Chardonnay-2
          Brix = 19
          pH = 3.0
          TA = 8 g/L
          SO₂ = 50 ppm
The juice pictured in the glass is the starting color of the Chardonnay. We like it already. We could be a little biased.