The concept of terroir promotes philosophical argument for many reasons. Not the least of which is determined winemakers can easily defeat the results. Succinctly stated, the idea is: two identical grapes grown in separate vineyards will have different taste and smell characteristics. Most people are on-sides up to this point. Many Europeans, however, further feel that great wine has an obligation to reflect the taste and smell characteristics of the location where the grapes were grown. That is the point where a lot of Americans clamber off the bandwagon.
Americans expect a winemaker to produce a superior product by blending different vineyards together, or by using certain winemaking ‘tricks’ to emphasize ‘pleasing’ characteristics. Hence the name wine maker. To a European purist those interventions are a “hoax.” Europeans in charge of wine production on an estate call themselves ‘cellar managers.’ They think of themselves as baby-sitters: keeping the wine safe; not trying to influence its development. This matter leads to vigorous debate, with no right or wrong answers.
In the first video of our series, Terroir Tastings, we covered the reasons why wines made from Cabernet grapes grown on the hillside taste differently than wines made from grapes grown on the Bench or on the valley floor. For our fourth video in the series we wanted to use Merlot as our demonstration for why grapes in the southern part of Napa Valley taste differently than those in the northern portion. Our emphasis was on Napa climate. Cool air off San Pablo Bay is drawn north up the Valley as hot air rises over the sun-baked earth around Calistoga (note raptors circling in the updrafts to gain elevation at Calistoga). Different districts are defined by how the topography affects that mass of cool moving air. So the hills just north of Yountville separate the cooler districts of Carneros and Oak Knoll from the warmer ones of Oakville and Rutherford. Then the sides of the Valley constrict. The narrowest point is north of St. Helena, making the broad area south of Calistoga its own unique district.
Medoc upper left; Pomerol & St Emilion lower right.
In our video lesson we attempt to contrast how Bordeaux instead differentiates districts by soil. Their climate is much the same all over, but the soils in major districts are different. The Medoc~ on the outside of the curve of the river where the water would have run fastest over ten thousand years ~ has much more vineyard area with pebble-sized rock and sand. Sand is technically defined by geologists as up to 2 mm in diameter, about the size of the pupil in your eye. These soils drain well, ripening grapes earlier in a rainy climate. The French say the Medoc has “warm” soils. That’s why the Cabernet Sauvignon goes there, because it takes the longest to ripen. The Right Bank~ inside of the curve where the river would historically eddy and be much slower ~ contains a lot more silt (particles up to 0.05 mm in diameter, which you can barely see) and clay (< 0.002 mm, can’t see it without a microscope). These small particles have thousands of times more surface area to which water can adhere. The French call the soils of the Right Bank“cool.” They prolong vegetive growth of the vine each year, which slows down ripening. That is why Merlot and Cabernet Franc are preferred in Pomerol and St. Emilion. They ripen faster than Cabernet Sauvignon does.
Soil particle sizes
Ch. Latour in the Medoc.
Clay soil in Pomerol.
Demonstrating our thesis about climate in Napa Valley required assembling four wines (all 2010): Truchard from Carneros; Trefethen from Oak Knoll, Frog’s Leap from Rutherford; and Barlow from Calistoga. They are all properties with good track records. The wines are all highly rated by various reviewers. The wines all cost from $30 to $40. Then we sat down to taste them.
Welcome to the wonderful world of fine wine. We had two guest tasters: Katie Hunter from ace PR firm Charles Communications, and John Rodeno who works for Hahn Estates. John has grown up in the Napa industry. His mother Michaela ran St. Supéry for many years and helped found Women for Winesense. His father is a prominent Napa land use attorney. Both Katie and John are relatively young, but they are experienced with wine, and they are confident in their taste opinions. They liked the wines just fine. They just didn’t think the wines reflected any of the taste characteristics one might expect from the districts in which they were grown.
Truchard was the darkest, most full-bodied, and most robustly flavored of the bunch. Really good wine, but clearly the winemaker had left the grapes on the vine for an extended period, then done a long maceration on the skins, and probably attached some donkeys to the press. There were no herbal smells, and no indication (less ripeness) of the cooler Carneros climate at all. Barlow, by contrast, was lighter bodied. It had blueberry smells, but cropping at 8 tons/acre on an irrigated alluvial fan had produced a wine more noted for refinement than for concentration. There was absolutely none of the manhood-challenging intensity that the Calistoga district often flops out on the table. Frog’s Leap got a lot of attention for potential food matches, but it was the wine with the herbal notes. No one says “herbal” is typical of Rutherford, even for Cabernet Sauvignon, much less for Merlot (which ripens two weeks earlier than Cab). “Herbal” is a phrase people use to describe Merlot from cooler vintages in the Medoc, which is contiguous with an ocean estuary. Clearly, these Frog’s Leap grapes had been consciously picked early to achieve a Bordeaux style of wine.
The Merlot tasting with John and Katie was very instructive. They are both articulate and perceptive. Although the tasting mostly demonstrated the reverse side of our terroir coin ~ motivated winemakers can overcome terroir. It’s a lesson. Not the one we wanted to teach, but a lesson all the same.
