Category Archives: Wine Maker’s Corner

Wine Snobs And Their Cronies

I analyzed this subject very carefully and arrived at the conclusion that there are three kinds of wine snobs: The Regular Wine Snob, the Fake Wine Snob and the Wannabe Wine Snob.  In this article I will describe each one of them at length.

The Regular Wine Snob is a special breed of wine lover that has the need to proclaim his superior knowledge of wine which we are not supposed to question.  He only drinks wines from specific regions and non from others, from specific vintage years and only from a handful of special wineries.   All the others are “haram” (which means forbidden in Arabic).

A Wine Snob believes he knows everything there is to know about wine.  If you offer him a Cabernet, he will ask you for the region.  If you tell him the Sierra Foothills, he will say forget it brother!  If you say Napa, he will ask for the name of the winery.  Even if he approves the winery, he will ask for the vintage year.  If the vintage is younger than 10 years, he will walk away with disgust. 

A Wine Snob buys wines only from wineries that are on allocation and have a long waiting list of at least five years before they will accept you as a customer.  The Wine Snob brags that he has such good connections with all these wineries that he will get accepted as a customer instantly.

Wine Snobs like to talk about their conquests.  One of my Wine Snob friends told me the following story:
“When I visited Bordeaux in 1989, I was invited by the winemaker of Chateau Lafite Rothschild to come and visit him at the Grand Chateau for a tasting from his private collection.  When I got there, the winemaker had a bottle of 1956 Grand Crus Lafite Rothschild, all prepared on the table with two 18th century Riedel glasses, the size of an average melon, and a decanter.  He proceeded to pull the cork, not in one piece but in crumbles and a funky, musty aroma of barnyard and horse blanket filled the air. This is not abnormal for a wine of this age, which incidentally was still totally at its peak to show such wonderful aroma characteristics. 

We waited patiently for almost an hour, without saying even one word, since he didn’t speak any English and in spite of my vast knowledge of wines and winemaking, I can’t say that I mastered the French language either. My winemaker finally poured the wine very carefully and with precision into both glasses.  I proceeded to scrutinize the wine, the best way I knew how, from bottom to top.  First, I watched with admiration the metallic, electric brown color and the thick legs that formed on the walls of the glass.  Then I proceeded to take a whiff, one nostril at a time from both sides of the glass so that I don’t miss even a small molecule of this vastly complex wine.  Then I took a sip to cleanse my tongue, first regurgitating it up and down and from side to side until my tongue felt clean.  The second sip sent me to heaven.  But this is not the end of my story.

“2 + 2 = 1” . . . . Our Newest Wine . . . . A Fascinating Story . . .

I am very excited to introduce a new wine called “2+2=1.”  This is serious, I am not joking.  It’s the kind of math that only Einstein can understand.  I created this wine in collaboration with JOLO, a very fine winery from North Carolina, recently nominated as one the seven best wineries outside of California.

The name “2+2=1”

denotes that this wine was created:

By 2 winemakers,

JW Ray from JOLO Vineyards & Winery, Pilot Mountain, NC

and Chaim Gur-Arieh from C.G. Di Arie Vineyard & Winery, Mt. Aukum, CA;

Using grapes from 2 wine regions, 

North Carolina and California;

(East meets West)

Creating 1 wine,

unusual one, deserving such an exotic name.

“2+2=1” has four components, one coming from the JOLO Vineyards and the other three from CG Di Arie.  The major wine variety in this wine, Cynthiana (40%) was contributed by JOLO. Cynthiana, which is now also known as Norton, at first was thought to be a different variety.   However, with the advent of DNA testing, it was shown to be identical to Norton, the first Native American variety.  This variety was created in the 19th century by Dr. Norton whose origin goes back to one of America’s founding fathers, Thomas Jefferson.  Jefferson, a wine lover who tried to cultivate a wine culture in his new land, did not know that Dr. Norton was experimenting with grape varieties that could produce the quality wines of the old world.  Dr. Norton, after having a very tragic occurrence in his early life, losing both his wife and newborn child, immersed himself into this project. After his discovery of the Native American grape that would take his name, Dr. Norton commercialized the grape and made it available for purchase.  In 1830, the vines found a home in Missouri, which would become the wine capital of the new country, and Norton the signature grape.  Norton is a hardy variety that is impervious to disease and can survive extreme weather conditions.  This is what made it an ideal wine variety for the kind of environment present in Missouri. 

The other three varieties used in “2+2=1” contributed by C. G. Di Arie are Cabernet Franc (20%) originating in Bordeaux; Zinfandel (20%) from Croatia; and Petite Sirah (20%) from Rhone. It is quite remarkable that these four different varieties coming from different parts of the world can live together so harmoniously and create such a well-balanced wine having one of the most unusual and eclectic flavor profiles.

“2+2=1” will be bottled simultaneously but separately by C.G Di Arie and JOLO in July.  A total of 175 cases will be bottled by both wineries.  At the onset, this wine will be available for sale as futures, only to the wine club members of each winery, with a maximum of two bottles per member, on a first-come, first-served basis.  There will be a release party for the wine in both locations, in Mt. Aukum, CA and Pilot Mountain, NC.  Both winemakers and their families will attend both parties.  Stay tuned ….!


Chaim Gur-Arieh

May 2019

Terroir (Revisited) and how it relates to the culture of aging wine

While I already covered the subject of Terroir in my January 2018 Winemaker’s Corner, I decided to revisit this topic since I feel that I left this article somewhat unfinished.  If you are interested in reading my first article, please visit my blog, which you can find on our website

The concept of Terroir, pronounced “terwah,” was derived from the French word “terre,” which means soil or land.  It is presumed that the land at which the grapes are grown imparts unique characteristics to the wine that distinguishes it from wines grown elsewhere.   While I do agree with the above statement, I have a few qualifications.  While the Terroir has the potential of defining the character of the wine, there are factors that tend to mask this character: 

Farming – In order to preserve the character of the Terroir, the farming techniques should promote uniformity in the level of ripeness of the fruit.  At harvest time if some of the fruit is under-ripe, while some is over-ripe, the effect of the Terroir will be diminished, making the wine more generic.

Harvest Decision – There are no objectively measurable parameters to determine the level of ripeness of grapes.  Many winemakers use the sugar level as a guide for harvest.  Often times this leads to premature harvest, which will mask the effect of the Terroir.  I make my harvest decision subjectively, by tasting the fruit.

Winemaking Style – The use of excessive levels of oak or making the wine highly alcoholic will tend to diminish the Terroir character of the wine.  

The title of this Newsletter promises to relate Terroir to the “Culture of Aging Wine.”  It is not so obvious that there is a connection between Terroir and aging of wines.

An interesting question that I am always asked is how Terroir affects the character of the wine.   In climates that are consistently warm, with large temperatures drops from day to night, usually the wines become fruitier.  These are the typical climates in “New World” wine regions.  Climates having inconsistently high or low temperatures, with lower temperature drops between day and night, the grapes will have a more difficult time ripening, resulting in wines that are less fruity, higher in tannins and more austere. This is the case in old world wine regions.

The culture of aging wines was created in the old world countries for the simple reason that old world wines are not so pleasant to drink when they are young.   As old world wines age, they become smoother, better balanced and develop more exciting flavors.  While new world wines may also benefit from aging, many people find them quite adequate to drink when they are young.  Ninety percent of the wines produced in the world are consumed within the first year of production.

If you are a winemaker in the new world and you are passionate about making wine, my advice to you would be to try to maximize the character of the terroir but also age the wine for a few years before offering for consumption.

Cheers, Chaim Gur-Arieh

Old Vines Make Better Wines – Myth or Reality

It’s quite common among wine drinkers to believe that “Old Vines Make Better Wines,” since this statement has been traditionally supported by many influential wine magazines and reviewers.  In my opinion, this is not a question that can be answered with a “yes” or a “no.”

I recently purchased 15 different brands of Zinfandel at price points ranging from $10.99 to $19.99.  I was surprised to find out that 10 of them had the “Old Vines” statement on their front label. The wines made with the “old vines” were not consistently dark and complex in character like you would expect.  Some of them were as jammie and fruity as the wines made from the so-called “young vines.”

Unfortunately, there is no legal or commonly accepted definition of “Old Vines.”  Since the name “Old Vines” gives the wine a marketing advantage, it behooves the regulators to establish a definition of “Old Vines.”  In my opinion, vines should be at least 50 years old before they can be considered “Old Vines.”

I think that the generalization of “Old Vines Make Better Wines” can be fallacious.  I have seen some very young vines producing excellent wines.  The Syrah and Petite Sirah that I planted in 2001 have consistently been making excellent wines from the first harvest in 2004.  On the other hand, the Zinfandel that I planted in the same year has been a late bloomer.  It wasn’t until 2012 that these vines started producing some decent wines.

In general, the reasons why old vines have the potential for making good wines are as follows:

  • Old vines have deeper roots, which may have some positive or negative connotations.  The deeper roots go through different types of soil, with each type having some influence on the flavor of the wine.  This could have a positive effect on the complexity of the wine. 
  • As a vine ages, it loses its vigor restricting the amount of fruit bearing capabilities of the vine.  This might have the potential of producing more flavorful fruit that makes better wines.  We can accomplish this in young vines by dropping fruit or restricting the amount of water given to the vine during the growing season.

On the other hand, I will share with you some issues that I have regarding the “Old Vine” statements made on wine labels:

  • For an old vine to produce a great wine at an old age, it had to be producing good wines when it was young.  I don’t believe that getting older will make a mediocre vine produce great wines.
  • When I see a claim on the back label that a wine is made from a vineyard that is 100 years old, I ask myself if the entire vineyard is 100 years old.  I know from my experience that over the years a part of the vines will die.  Like in my vineyards that were planted 17 years ago, about 2% of the vines died, which were promptly replaced.   When my vineyards reach 100 years of age, maybe 50% will have died and replaced.  To be truthful, the claim should be as in the following example:  “About 50% of the vines used in this wine came from 100-year-old vines, with the other 50%, the age is unknown.” 

Obviously, nothing lives forever.  At some point the vineyard that was planted a long, long time ago, will lose all the vines from the original planting.  Should we still call this wine “Old Vines?”  I wonder!


Cloning – An Old Art in a New World

My winemaking career began in the year 2000 after my wife Elisheva and I decided to purchase 209 acres of raw land in the Shenandoah Valley AVA in El Dorado County. Within a couple of years, we built a winery and planted 20 acres of vineyards, which were expanded to 45 acres over the years. I consider myself a farmer and a grape grower as much as a winemaker.

One of my most significant achievements as a grape grower has been my success to grow Cabernet Sauvignon grapes in this region. I can attribute this success to two factors: changing the architecture of my trellis system to provide shading of the side of the vineyard facing the afternoon sun, along with the proper clonal selection of the Cabernet vines. I find the concept of clones and clonal selection most fascinating and decided to discuss this subject in this month’s Winemaker’s Corner.

A clone is defined as a genetically uniform group of plants, derived originally from a single plant by asexual propagation, mainly by grafting. All plants derived from one clone are expected to be identical.
On the other hand, when selections of vines of the same variety from different sources and locations are compared, one may find subtle to significant differences. These differences are magnified when a plant is relocated from one environment to another. In the beginning the new environment will seem hostile. In an effort to survive, the plant will try to acclimate, adjust and change. The changes that occur in the plant are known as mutations. Over time, mutations may accumulate creating a potential of affecting the fundamental characteristics of the plant, such as the size of the berries, the shape of the cluster, the color, the flavor profile, disease resistance, harvest time, yield and more. A selection of plants that undergoes this level of changes are known as “clones” of a variety.

A classic example of clone diversity is Zinfandel and Primitivo. They both originated from a Croatian variety known as Crljenak Kastelanski, which migrated to Italy to assume the name Primitivo and separately to America where it was called Zinfandel. These two clones having identical DNA’s, were separated for 200 years growing in very different environments. I grow both clones in my vineyard and can tell you that they are fundamentally different: Zinfandel has big and very tight clusters with large berries, while Primitivo has smaller and looser clusters with small berries. The flavor profile of the two wines is also quite different. Furthermore, Primitivo has a higher level of tannins and denser color than Zinfandel. They definitely don’t look alike.

Going back to our Cabernet project, I attribute our success to the selection of clones that are able to withstand the rigors of our hot weather. Most of the common clones of Cabernet find our weather too harsh, which prevents them from going through the process of normal ripening.

One final note: In addition to cloning, which is asexual, plants can also be created by sexual propagation by either man or Mother Nature. An example of a manmade variety through sexual propagation is Petite Sirah, created by crossing Syrah with an obscure variety called Peloursin. A more famous variety created spontaneously in nature by sexual propagation is Cabernet Sauvignon, a crossing of seeds of Cabernet Franc and Sauvignon Blanc. My question to you is this: Can we duplicate Cabernet Sauvignon by crossing seeds of Cabernet Franc and Sauvignon Blanc? I think you know the answer. You can duplicate Cabernet Sauvignon sexually, as much as you can duplicate your son Joe. The only way to have Cabernet Sauvignon is by cloning. Get it?


Terroir… and AVA’s (American Viticultural Areas) Are they one and the same?

If you have been to any of my “Tasting with the Winemaker” sessions in our tasting room, chances are you heard me saying, “A wine has a sense of place.” What this really means is that a wine acquires some unique characteristics from the geographical place that the grapes are grown which can identify the region. The classical name for a “sense of place” is terroir, derived from the French word terre, which means land.
The concept of terroir (pronounced “terwah”), was created by the French and is the basis for the French wine appellation d’origine contrôlée (AOC) system. The AOC system presumes that the land from which the grapes are grown imparts unique characteristics to the wine that distinguishes it from wine grown in other regions. In old world wine regions, this concept is taken to such an extreme that wines are not identified by their variety but by the region in which the grapes are grown. As an example, in Burgundy, winemakers believe that they are producing a Burgundian wine that happens to be Pinot Noir and not a Pinot Noir from the Burgundy region.
The new world wine producing countries borrowed the concept of terroir from the French but interpreted it in their own way. In the United States we established the American Viticultural Areas (AVA’s) which are the designated wine growing regions. According to our rules, a wine has to be identified by the variety of the grape, provided it uses a minimum amount of this grape and the AVA in which the grapes were grown. At this time, we have 107 appellations and sub-appellations in California with the first being Napa Valley which was designated in 1981.
Conceptually, what creates the terroir are natural elements beyond the control of human beings. The major ones are climate and composition and type of the soil. Viticultural practices and winemaking techniques can either increase or decrease the expression of terroir in a wine. In winemaking, excessive use of oak, high alcohol levels in wine or blending for the purpose of modifying some attributes that are a part of the varietal identity are among those that will tend to mask the influences of terroir. On the viticulture side, in order to emphasize the effect of terroir, we need to create conditions in the vineyard that will promote uniformity.
The concept of terroir also carries a perception of exclusivity and quality. It is not a given that every wine made in a specific region will fully utilize the potential of the terroir. Terroir is like a god given talent that requires learning and discipline to achieve its prospects. Sometimes people misunderstand the concept of terroir. Terroir creates diversity as opposed to exclusivity. Just because a wine comes from an AVA that has a reputation of producing some top wines does not mean that any wine made in that region will excel.
Napa Valley, which is considered one of the premier wine regions of the world, got a break in 1976 because of the Paris Wine Tasting, better known as “The Judgement of Paris,”, which resulted in a Napa Cabernet Sauvignon and Chardonnay beating several French well-known labels in a blind tasting. This is what put the Napa Valley region on the map. With its 16 sub-appellations, Napa Valley is a very diverse grape growing area. While St. Helena, Rutherford, Oakville, Yountville and Staggs Leap are considered moderately warm, Los Carneros, Mount Veeder and Atlas Peak have cooler climates. The question is why combine these sub-appellations which show distinctive differences in their Terroirs into Napa Valley? I thought that the idea of creating AVA’s was to establish wine regions with specific identities.
I think that I will stop right here. Since this writing is generating more and more questions that I know not their answers. As they say in French “cela suffit , merci” “That’s Enough, Thank you!”

The Cork and Wine – A Friend or a Foe

Cork has been the traditional closure for wine bottles. While cloth, leather and clay closures preceded cork, it became the closure of choice in the 1700 after glass blowers were able to manufacture wine bottles of uniform size, shape and design.

Some winemakers and other wine aficionados think that the choice of using cork as a closure for wine bottles brought fine wine into modern age, since it provided the ability of wine to age and evolve in the bottle …….. at least winemakers from the past and some that have strong traditional convictions think this way. Four centuries later, the majority of winemakers that claim to be creating quality wines are still using the cork, even after there is a clear and scientific understanding of the pitfalls of cork.

The proponents of cork list a number of important advantages for using cork. The most important advantage cited is that it allows the wine to be selectively oxidized on a micro level to aid the wine age and develop qualities that are not present when it is young. Other advantages cited are, that it is natural, originating from the bark of a tree, biodegradable, recyclable and created in nature from plants promoting biodiversity.

Some traditionalists say that “cork is a remarkable closure … having elastic and compressible qualities ideally suited for wine.” My response is that cork is the most “ununiform” among closures. There is a significant variation in the hardness of corks. Some are soft and allow more air to penetrate through and after prolonged aging these corks will be soaking in wine. Others will become fragile and break in the bottle while you try to pull them out. This results in an inconsistency in the quality of the wine from one bottle to the next.

The major flaw of cork is that during production it gets contaminated with a chemical known as TCA (Tri-chloro-anisole). TCA is created when the wood is treated with chlorinated phenolic compounds to inhibit the growth of fungi. TCA is responsible for the so called “wine taint,” which gives a very potent, repulsive flavor and aroma to the wine. The smell of wine taint can be detected in parts per billion. Statistically, it has been proven that 7 – 10% of wine is contaminated with TCA, equivalent to a bottle per case. Is there any other industry in the world that will accept a 7% failure rate?

There are many viable options to the cork. I have been using one since my 2007 vintage wines. Called Diam, this is a composite cork, made from cork matter that has been ground and pressed using a natural binding compound. It has uniform density so that it doesn’t allow the wine to penetrate through and soak the cork. The wine does not become tainted since all the TCA has been removed during the process.

While I was doing my reading for this newsletter, I ran across an article describing regulations that were enacted in 2006 in some of Spain’s top wine growing regions outlawing the use of alternative wine closures for wines produced in those regions. Quoting them: “Spanish lawmakers and wine producers are responding for what wine drinkers the world over have been telling us for a long time – cork is a sign of quality for wine.”

I say they got it all wrong! Whoever accepts a bottle per case of tainted wine is not thinking about quality!

Cheers, Chaim

Age-Worthy Wines – 2007 D’Arideaux Rouge – The Best

I am into my 18th year of winemaking. I went through 17 harvests and made about 200 different wines. Since I had been a wine collector for many years before I became a winemaker, it was very normal for me to want to set aside every year a few cases of the wine from my yearly production. Recently, I became curious about the state of my older wines and decided to run an inventory. To my surprise, I discovered that I have 50 different wines that are older than 10 years with at least one case left over. I have 20 wines that are 10 years or older with 20 cases left over.
I became very curious to find out whether these wines had any level of age-worthiness. I must point out that what I am looking in age-worthy wines is not whether the wine is enduring the aging process, but rather is it transforming itself and revealing qualities that were not so apparent when it was young. I decided to make these wines a part of my daily diet and during the last six months, most of the wines that I had with my dinner have been from my collection of Di Arie older wines, made at least 10 years ago. I also included from my collection some old world and California wines that go as far back as the early nineties.
It is common knowledge that the factors that affect the age-worthiness of a wine are the variety, the viticulture practices and the winemaking techniques. I always brought all these factors into consideration in my winemaking protocols hoping that my wines would be age-worthy.
It has been very exciting to open a bottle of wine from the distant past that originally had left a memorable impression on me and to find out that during this aging process it acquired some unusual qualities making the wine more complex and subtle. While most of the wines that I tasted benefited from aging, some reached their peak and started to decline earlier, while others continued their positive transformation all the way to my first vintage of 2001. In general, my Zinfandels showed a shorter life span than all my other wines, starting their decline before their 10th birthday.
I was so excited by this revelation that I decided to create a new category of wines on our website called “Age-Worthy Wines.” I have included three wines in this category: 2005 Sierra Legend, 2005 Southern Exposure Syrah and 2006 Proprietor’s Blend. These wines, which were outstanding to begin with, have transformed to become exceptional wines. I will keep these wines on the website until sold, and then replace them with others of equal quality that are at least 10 years old.
This leads me to tell you about this month’s Gallery Collection Club release. After tasting all these wines from the past, I got a brilliant idea to share with you one of my old gems. This month’s Gallery Collection release will be my 2007 D’Arideaux Rouge. This spectacular wine, which has gone through a positive transformation, is proving to be very age-worthy while not showing its age. In my opinion, this wine is not even close to reaching its peak of quality. While it still possesses a dark and dense red color and strong aromas of dark fruit, it became more complex, acquiring earthy, leathery and savory flavors.
I am very happy that I had the foresight to make enough of this wine so that I can release it to my Gallery Collection club more than 10 years after it was conceived.
Cheers & L’Chaim

2014 SandFire Red

With the release of a wine that I named SandFire Red we are celebrating the third anniversary of the Sand fire, which came very close to devastating our winery and our home in 2014.

On July 25, 2017, a day before my birthday, the pungent smell of smoke woke me up at 5:00 AM.  I rushed outside expecting the property to be engulfed with a fire like the one we had exactly three years ago, on my birthday.  But all I could see was a thick cloud of smoke.  Unlike the fire that started on July 25, 2014 raging a few feet away from our house, this time it was a few miles away on the south hills adjacent to Omo Ranch Road.

On July 26, 2014, I wrote in my diary:

“I refused to believe that the fire that started on Sand Ridge road and HW 49, 5 miles west of the winery, on Friday July 25, a day before my birthday, was going to affect us.  Friday morning we left the winery for a weekend of celebrations for my birthday.   We were hardly a day in the Bay Area when I started receiving text messages from my neighbor Mike that has a house straight west from our house.  At some point he texted me that with the help of “two giant bulldozers, 20 fire trucks and hundreds of firemen the fire was contained around his house and now moving towards ours.”   His next text message came as we were on our way to have dinner at the One Market Restaurant in San Francisco.  It said, “I can’t see your house, it is engulfed with flames that are 200 feet high.”   Needless to say that my birthday dinner was less than joyous.  By the time the dessert arrived his text message read, “We can still see the roof of your house behind the thick smoke.”

We could not wait until the next day.  We cancelled all the events that we had planned and went back to the winery to see the damage with our own eyes.  While both accesses to the winery from D’Agostini and Upton Road were blocked by police we were able to persuade them to allow us in.  When we arrived the fire had been contained about 30%.  We still observed about 100 helicopter sorties dumping water and chemicals on the surrounding areas of the house and the winery.  By this time there were about 190 fire trucks and in excess of 1000 fire fighters fighting this fire.

Bottom line: Except for about 20 acres of forest that burned down on the west side of the house, the house and winery were spared.  We had smoke damage inside the house with minor smoke damage in the winery.  Most of the vineyard blocks  were not touched by the fire.”

Our 2014 SandFire Red is a blend of Zinfandel, Syrah and Touriga Nacional.  The Zinfandel vineyard, that provided the grapes for this wine, is located far away from the fire, while the Touriga and Syrah are in the close proximity.  I purposely emphasized the smoky flavor and aroma in this wine to make it fit for the occasion.  After all, it represents a fire that burned 4240 acres of land  in our immediate neighborhood.




Weather, Degree Days & the Quality of Wine

People have been asking me how this year’s wet weather will affect the quality of the 2017 vintage wine. We must have had at least 70 in. of rain, more than double the average yearly rainfall.  The rains kept coming down all the way into the month of June.  While at times, some parts of the vineyards were flooded, I do not see that this will have a lasting effect on the quality of the wine this year.  Erosion has been minimal even on some of the steeper slopes mainly because of the well-maintained cover crop.  Bottom line, the excessive rains had no significant effect on the quality of the crop, so far.  Nevertheless, it is not time to rejoice. We must keep in mind that this is only the beginning of the growing season and a lot can happen between now and harvest time.

In the following paragraphs I will try to give you an insight how the weather, during the growing season, may affect the quality of the wine.  A.J. Winkler, a professor at Davis determined empirically that it takes so many degree-days during the growing season to get the grapes of a specific variety to an adequate level of ripeness to make good quality wine. This is called Growing Degree Days (GDD).  He assumed that the grapes would not ripen at a temperature below 50 degrees.  Therefore, he calculated the GDD by subtracting 50 from the average temperature for the day.  The average temperature for the day is the highest temperature plus the lowest temperature divided by 2.  Thus, the GDD for the day that has a high of 95 degrees and a low of 60 degrees (typical weather in the Sierra Foothills in August)  will be (95+60)/2 – 50 = 37.5. If this weather persisted for 31 days during the month of August, the cumulative GDD for August would be 1,162.5.  Winkler determined the “growing season” to be between April 1 to September 30.  He developed the Winkler Index, which is based on the Growing Degree Days summed up over the “growing season” in different regions.  Based on the average GDD he classified five different growing regions and identified different grape varieties that can be fit to each of these regions. I will only show the data for three of these regions since they are the ones that would apply to the regions in California and the varieties that we grow.

  • Region I: Below 2,500 degree days;

Varietals:  Chardonnay, Pinot Noir; Region: Burgundy

  • Region II: 2,500-3,000 degree days;

Varietals:  Cabernet Sauvignon, Merlot, Sauvignon Blanc; Regions: Bordeaux, Napa

  • Region III: 3,000-3,500 degree days;

Varietals:  Zinfandel, Barbera, Tempranillo, Grenache, Syrah; Regions:  Sierra Foothills,    Piedmonte, Barossa Valley

Unfortunately, the Winkler Index is not very accurate or reliable since it does not bring into consideration all the weather factors that play a role in the ripening of grapes.  It does not take into account the effect of the temperature variations between day and night on the ripening.   Hypothetically, a region that would have an identical day and night temperature, say of 77.5 degrees would have the same GDD as one that has a day maximum of 95 and a night minimum of 60 or one that would have a day temperature of 85 and a night of 70. All three would have the same Index and would be classified as the same region. In reality, they would be worlds apart in the way grapes would grow and ripen.

Conclusion – Take it from me!  Don’t use GDD’s for decision-making!  Use them for information only!



July 2017