Albemarle Terroir

Pollak Vineyards is opening up their barrels to the public next weekend.  I am planning on going and trying out last years crop.   This will be my first ever barrel tasting.  I look forward to trying it out and writing about the experience.

On December 19, 2009 it snowed in Charlottesville and Albemarle County.   The relation to wine?  None.  But I had to write about this (I’m a meteorologist, after all).      The snow started on Friday the 18th at about 4:30 PM.   By  8 AM the next morning we had about 23 inches of snow at my house.

Snow in Charlottesville

During the day a few more inches of snow fell.   The official snow measuring methodology (which no one does anymore) is to measure how much snow falls in a hour on a clean, flat plate.   Wipe the plate clean and wait another hour.   This minimizes the amount of snow compaction.   I’d estimate that method would have generated 28-30 inch measurements.

The roads into my neighborhood still have not been plowed as of Sunday evening.

Snow Sliding off the Roof

The Virginia Department of Agriculture and Consumer Services recently released statistics showing the Grapes reached the top 20 by value in agricultural production.     The Cville Weekly reports that in 2008 Albemarle County grape production increased 20%.    Unfortunately, I can’t find the original report referenced in the story.

Somehow a whole growing season passed without any Bordeaux climate updates.   Here it is.

Bordeaux 2009 Growing Season Temperatures

The climate is fairly unremarkable in terms of both temperature and precipitation.   The first graph shows the daily average temperature at the Bordeaux-Merignac airport.  With only one significantly warm period,  it’s safe to say the temperatures were rather average.   In fact,  the average temperature of 2009 from April to Sept 1 is only a few tenths of degrees different than the long term average (red line).

Amazingly, precipitation is no different.

Bordeaux 2009 Growing Season Accumulated Precipitation

The early part of 2009 (blue line) was wetter than average but the latter half of the season has been drier than average.  Since the two lines practically touch,  the precipitation this growing season is right on average as well.

The implications of this is that the quality of wine in Bordeaux will be neither outstandingly good or bad.   2009 should NOT end up being an outstanding vintage.  Not a bad one, either.

Coming next,  I’ll apply the Ashenfelter model to develop  a quantitative estimate of Bordeaux wine quality for 2009.

Below I have prepared two graphs that detail the development of the 2009 Albemarle County Wine climate through the end of August 2009.

Based on earlier posts on this blog regarding Bordeaux and California wine quality and climate, the Albemarle season is not shaping up to be great one.      The precipitation graph below indicates the early part of the season (I assumed the wine growing season started on May 1st) was wetter than average.  Likewise the Heating Degree Day chart (HDD) shows the summer has been cooler than normal.

Ashenfelter et al.  indicates the best vintages in Bordeaux come from summers that are warmer than normal and drier than normal (but with ample preseason precipitation to ensure good ground moisture).

2009 Albemarle Country Accumulated Precipitation

The early portion of the summer was wetter, based on this accumulated preciptation graph.  Note how the slope of the red line (2009 rainfall) is steeper than the blue line (average accumulated rainfall).   So,  it rained more than average in the early portion of the summer, which may not necessarily be bad except that it kept raining during the summer with only a brief period of reduced rain accumulation rate.

The Degree Day story is not much better.  The summer has been cooler than average (since May 1, anyway) as indicated by the red line (2009 summer) being below the blue line.   Again,  ideal wine gowing conditions tend to be warmer (but not too warm!) rather than cooler.

2009 Albemarle County Degree Days

One weekend in July,  my extended family and I visited the Pollak Vineyards here in Albemarle County.   Just about everyone was taken back by how good the Pinot Gris was.    It was so good, that I decided to give it to a friend for his birthday.    The only issue is that my fried lives in Shanghai, China.    Fortunately, I had plans to visit him in early August.

When I stopped by the vineyard to pick up a bottle I mentioned that I’d be carrying a bottle to Shanghai.   “Take a picture near something famous!” I was asked.   So, below you will find a few pictures of the well travelled Pinto Gris and the Shanghai Skyline.

The author and the wine.

Pollak goes to Shanghai

Up close and beautiful.

Pollak and the Perl Building

I’ve recently discussed several interesting weather/climate and wine related issues. In particular, a recent compared the daily maximum and minimum temperature climate of Napa Valley, Bordeaux, and Albemarle county. As discussed in a recent Charlottesville Daily Progress article, one of the major differences of growing wine in Albemarle County and surrounding regions is the effect of heat and humidity on grapes. To explore the heat element a bit further, this post will look in a bit more detail at the maximum temperature climatology.

In the chart below I show several types of data for Napa, Bordeaux, and Albemarle.

1) The thick lines have the same color coding as my previous post comparing climates in Napa, Bordeaux, and Albemarle and is identical to the average maximum daily temperature shown in that post.

2) The thin lines (labeled “Max”) are the highest maximum temperature ever recorded for a given day in each of the three regions.

3) The thin lines near the bottom of the graph depict the standard deviation of maximum temperature for each day of the year.

The standard deviation calculations indicate that, generally speaking, the standard deviation of daily maximum temperature during the summer growing season are all approximately the same. The Albemarle County standard deviations are generally larger during winter months. Interestingly, this is also true for daily minimum temperatures suggesting the risk of tissue damage due to severe cold temperatures in Albemarle county is greater than in Bordeaux and Napa Valley.

The risk of extreme temperatures, as measured by the highest recorded daily maximum temperatures is highest in Napa Valley. So, despite the average daily maximum temperatures climatology between Albemarle and Napa Valley being approximately the same, the risk of severe temperature extremes is much greater in Napa Valley.

Up next, discussion of the effect of heat damage.

Daily Average Temperatures for Bordeaux, Napa, and Albemarle County

Albemarle Terroir is supposed to focus on the terroir of Albemarle County and Charlottesville, VA in an effort to discuss what makes Albemarle Wine unique. The Blog is a platform for me to learn more about the effects of climate on wine and is a great excuse to dive into some climate data.

I’ve discussed papers that explore climate and Bordeaux wine quality, applied it’s concepts to Chateau Montelena vintage notes, and tasted some wine.

I recently read a few papers regarding the potential effects of wine on climate change
and decided it was time to compare the climate in Charlottesville and Albmarle County to Napa Valley and Bordeaux.

The chart above presents the average daily maximum and daily minimum temperatures for Albemarle County (Charlottesville Airport), Bordeaux (the Bordeaux Airport), and for Northern Napa Valley (the St. Helena CIMIS station).

The legend includes:

1. Bd = Bordeaux (Blue)
2. Napa = Napa Valley (Red)
3. Alb = Charlottesville/Albemarle County (Green)

There are a number of weather related risks a vineyard can experience that tend to decrease either the yield of their vines or the quality of the grape juice used to make the wine. They include:

1. Extremely cold winter temperatures which damage the tissue of the vine
2. Spring frost damaging the newly grown buds
3. Excessive heat
4. Rain during the harvest period
5. To little rain during winter (the soil does not rebuild is water stores after the dry summer and fall)
6. Hail

Despite all those risks, temperature is the most important determinant of a regions ability to grown quality grapes for wine production. A wine growing region needs to have a temperature high enough that allows a specific grape variety to grown to maturity during the summer months but not so warm that table grapes or even raisin grapes are produces.

Most people who consume wine on a regular basis have some awareness that the worlds best wines come from Bordeaux and Napa Valley. They may not realize that their climate play a huge role is making them great grape growing regions. The notes below discuss the differences in average temperatures between the three regions and their implications for grape growing.

1. I was quite surprised at how similar the average daily maximum temperatures between Napa Valley, CA and Albemarle County, Virgina are. The warmest days of the year have a surprisingly similar daily maximum temperature climatology.
2. Whereas the daily maximums between Albemarle County and Napa are similar, their daily minimum temperatures are not. Napa Valley’s summer time daily minimum temperatures are much lower than Albemarle County’s. This is almost certainly due to a generally drier, less humid Napa climate, allowing for cooler nighttime temperatures.
3. The Bordeaux daily maximum temperatures during the growing season (the summer period spanning the middle of the graph) are always less than Napa Valley and Albemarle County. However, the daily minimum temperatures are between Napa and Albemarle.
4. Albemarle County winter time temperatures are substantially lower than Bordeaux and Napa Valley. There is a long answer for why this is the case. The short answer is because Virginia has water to it’s right and a continent to it’s left where and Bordeaux and Napa are the reverse.

There is much more to come on this subject including a comparison of rainfall and extreme temperatures.  This post is the beginning of the exploration of   Albemarle County/Charlottesville  Wine and Climate

Last week on the way back from Lynchburg, VA to Charlottesville, VA I stopped in at Rebec Vineyards, which is just north of Amherst, VA.    The vineyard is located in a beautiful setting just off Highway 29 with several acres of vines surrounding the building where tastings are available.

I was albe to speak to Svetlozar Kanev the wine maker, who poured wine for us.    I launched right in to discussions of weather, climate, and wine.   Svet mentioned the vineyard recently experienced hail damage to  their grapes.   I’ve take a picture of the hail damaged vines (picture to be added later).
Rebec  currently offers 14 wines, of which I tasted 9.     They were Chardonnay, Viognier, Landmark White, Gewurztraminer, Riesling, Merlot, Cabernet Franc, and Cabernet Sauvignon.    The white wines were definitely on the dry side of the sweetness spectrum and may be well like if you enjoy dry white wines.   Unfortunately,  I tend not to enjoy dry white wines much and found these to be a bit too dry from my preferences. Overall,  none of the wines stood out above the rest, which sometimes happens during a winery visit.

I recently created a simple wine quality index to compare the vintage notes of the Chateau Montelena to daily weather records from St. Helena, CA.       In the post,  I used the variables of primary importance from Ashenfelter et al. 1995.  Since I did not have market pricing data to estimate the value of regression coefficients, I created simple weights from normalized weather data.   The normalized values were:

1. Accumulated Winter Season Rainfall
2. Average Growing Season Temperature
3. Assumulated Harvest Season Rainfall

The index result in a time series displayed below:

A Wince Quality Index for Northern Napa Valley

In this post,  I add a new component to the index and compare the results.

As an example,  the 1972 notes state “Record heat in July caused considerable damage”.

I’ve seen other reports of heat damamge or heat injury.  I recently created a quick post on heat damage as well.   So,  it seems only logical to add to the index a term that measures the likelyhood of heat damage.

The eqaution for the Quality index is:

I modified the equation to include a term that counts the number of days during the growing season that a daily maximum temperature of 95 oF is exceeded.   As before,  this time series is normalized, and only exceedances greather than average are applied.   The equation then takes the form:

The “Temperature Excedance” variable is a normalized time series of a count of the number of times daily maximum temperature execeeds 95 oF during the growing season.

The Wine Quaility Index based on the temperature exceedance (a measure of the potential for  heat injury) and the original Quality Index is displayed below.

A Heat Index based Wine Quality Index for Northern Napa Valley

In general there are no drastic changes to the quality index when heat index is added.  This is not unexpected since it’s wieght is only -0.25.   But, it may “fine tune” a few of the values.