I had to take a little more time to present this post because I received two questions in comments from my Uncle Brian and Aunt Terry that I wanted to discuss in a 2 part post. I couldn’t limit my answers to just a few sentences, and I wanted to make sure everyone involved had a chance to read and comment.
(part 1) From Terry: Is the soil you have analyzed compatible only with Cabernet Sauvignon?
(part 2) From Brian: What characteristics make an ultra-premium quality crop?
These two questions are what I am ultimately trying to answer with my project. What can we grow? And how can we make it the best? We have a lot of posts to get through until I think we can all begin to understand the concept of ultra-premium wine grape production, but my plan is to discuss this topic, literally, from the ground, up. With that said, I’d like to introduce a concept in vine production that should help, in part, to answer both questions.
We begin with the environment. Our environment not only includes climate, but geography, and the multitude of life surrounding us. I can assume we all agree this aspect alone is incredibly complex, but, for starters, let’s address climate.
To understand a ultra-premium crop, I think we should look around the world and study where there has been success, and where there has been failure. Lucky for us, others before have suffered a lifetime of trial and error to do just that. There is a system in place called “degree-days”, which helps growers and winemakers alike, categorize growing regions all around the world. This system links the relationship between average temperatures during a growing season, and what that means to vine selection.
To calculate “degree-days”, we must first determine the average temperature for the day:
(High Temp+Low Temp)/2 . i.e., the average summer temp in Napa might look something like this: (90+50)/2=70.
Now, we subtract 50 from this number to get a degree-day value of 20. Why 50 you ask? Simple! Vine growth will not occur when exposed to temperatures below 50 degrees Fahrenheit, so they simply do not count (this concept is only concerned with the number of degrees above 50, as these are the only temps in which the vine will be active). Now, do this everyday from April 1st to October 31st (the growing season), add them up for a grand total and you will have established your “growing region” as detailed below:
REGION I: up to 2500 degree-days (Rheingau, Germany; best known for the grape variety Riesling. Also, Burgundy, France: Pinot and Chardonnay).
REGION II: 2501-3000 (Bordeaux, France: you guessed it, Cabernet Sauvignon).
REGION III: 3001-3500 (Calistoga, California: Cabernet, Zinfandel, and some Italian stuff too! Tempranillo and Sangiovese).
REGION IV: 3501-4000 (Florence, Italy: a Tuscan favorite, Chianti: 70% Sangiovese, 15% Canaiolo and 15% Malvasia bianca).
REGION V: 4001+ (Riverside, California: They grow it all, whether you like it or not.)
What makes Napa County so unique is that, according to this system, it includes four growing regions: Los Carneros (I/II), Oakville (II), and Calistoga (III/IV).
Now, to answer the question: “Is the soil you have analyzed compatible only with Cabernet Sauvignon?”:
A wine grape-vine consists of two parts: the fruiting variety, a.k.a. the scion (Cab, Pinot, or Riesling), and a rootstock (cut and paste; Frankenvine, if you will).
Today, all rootstocks in the industry are of North American grape-vine species, due to the fact they are immune to an insect native to North America called phylloxera. Phylloxera attacks the roots, feeding on the tissue, which in turn stunts growth and will eventually kill the vine. Rootstock species consist of varieties I’m sure you’ve never heard of, and only people in the South actually dare to ferment their fruit for wine.
“WOOOOWWEEE that Vitis rupestris is full-bodied and smooth!”
To conclude, scion choice is decided on by your climate region and taste, however, the rootstock has every bit to do with how the vine operates as does the climate in which it grows. With that said, I think the rootstock choice, not the scion, would more so depend on the soil profile. Later in the project, we will be introduced to all three rootstock species, and after full analysis of vineyard soil profile and choice of planted variety, we’ll make a decision!
UP NEXT: Part 2 – What characteristics make an ultra-premium quality crop?