Friday, 6 December 2002
VINETECH and Château Cheval Blanc (St. Émilion)
Journalists: Tony Wolf, Susanne Becker, and Steven Haskill

VINETECH Conference in Bordeaux (Review 1 of 1)

Amazing array of small and large equipment. Most intrigued by some of the small equipment designed for operation in narrow (1.0 to 1.5 m wide) vineyard rows. Two potential or actual problems with much of this equipment: (1) the unique nature of some of the equipment means that a North American distribution is not an option, or parts/service would be very difficult to obtain. (2) I also thought that some of the equipment looked prone to breakage. That is, electrical fittings and plastic plumbing was often in exposed positions that looked susceptible to damage from snagging shoots or brush. A fellow traveler made the comment – the equipment looked like something the vineyard owner (purchaser) should use, not the vineyard workers.

Château Cheval Blanc (Review 1 of 3)

We missed Château Margaux due to a canceled AF flight at Dulles, but the Cheval Blanc visit perhaps made up for it, largely due to our host, Dr. Kees van Leeuwen. Kees liberally provided an excellent overview of vineyard management, a description of soils at Cheval Blanc, and a description of wine making. Cheval Blanc has 35 ha of vines under cultivation, 60% of which are Cabernet Franc, the balance Merlot. Row and vine spacing are typical of Bordeaux – 1.3 to 1.4 m between rows, with vines 1.1 to 1.2 m apart (6000 to 7500 vines/ha). Rootstocks are principally Riparia and 101-14. They want low vigor, but vines are still hedged three to four times per year. Training is simple Guyot. Canopies were vertically shoot-positioned with aid of catch wires. Additional canopy management during growing season consisted of:

Kees indicated that most of the vines are over 40 years old; that age dating back to the severe freeze of 1956, which killed many vines throughout France (-25 to -30°C). Kees indicated that from that experience they knew that Merlot was not as cold hardy as Cabernet Franc. Vines, such as replants, that are < 10 years old are harvested separately. No herbicide is used in the vineyard, only mechanical cultivation. When needed, organic N is applied, typically as cow manure. Pine bark is also used to amend soil organic matter. Disease management aimed principally at downy mildew. They spray 8 to 9 times/year for downy mildew using cimoxanil, ethyl phosphonate-Al (Aliette®), folpet, some copper, and strobilurins. Their second greatest problem is powdery mildew (sulfur, Sis, and strobilurins). Some Botrytis sprays are used, but we were told that no insecticides or miticides are needed. We saw evidence of pheromone dispensers used for mating disruption (“sexual confusion”) of the European grape berry moth.

A very interesting part of Kees’ description was that of the soils of Cheval Blanc. The property has three types of soil, and most of the wine is made from a blend of fruit that comes from two different soil types, profiles of which were displayed in the winery atrium.

  1. One soil is a sand/gravel mixture down to about 1.5 m, at which point there is a very compact zone which roots cannot penetrate. Water stress can be very severe (no irrigation is used in Bordeaux), but wine can be very good if yields are kept < 30 hL/ha. The wine made from vines grown on this gravelly soil have hard tannins and very nice aromas.
  2. The second soil is about 60% clay with a high shrink/swell capacity. This soil can become dry in summer and the resulting cracks allow deep root penetration. Wines made from vines grown on the clay soil are softer, have deeper color, but less interesting aromas. The clay soil is favored for the Merlot. Drainage tile is used on the clay soil, but this comment came late in the discussion and we did not pursue details of how common tiling is in this area.
  3. The third soil type is a minor (in area) soil for the property. This soil is sandy and roots can reach free water, even in the driest years, thus vines are never water-stressed. Wines were not as concentrated nor as complex as wines from vines grown on the other soils.

This site receives about 300 mm of rain between April and September (Winchester receives about twice that amount in the same period). Kees indicated that all the best vintages are from dry years (sounds similar to Virginia). The gravel soil is somewhat warmer than the clay soil, and budbreak is slightly delayed on the clay soil. Grapes ripened about the same time on the clay and gravel soils (#1 and #2); however, ripening was delayed about one week on the sandy soil (#3).

Clones: Here and elsewhere it was somewhat a moot point to discuss clone numbers, as either the proprietors had their own clones or the clones being used did not necessarily match clone numbers that we have in the US. Kees indicated that they had very good clones of Merlot and Cabernet Sauvignon. They did not, however, have very good clones of Cabernet Franc. Starting about 25 years ago, Cheval Blanc started a program of clone selection. He now feels that they have better clones. When asked the question about berry size, Kees indicated that “berry size is the primary determinant of wine quality”. [Editor’s note: Unfortunately, few Virginia producers determine berry size/weight.]

Visit at Cheval Blanc (Review 2 of 3)

Entrance to wine cellar - electronic sliding doors; on each side of the entrance there is a display of the soils of the estate: gravely soil to right- clay soils to the left. In contrast to what is believed to be good for the varieties Merlot and Cabernet Franc, the Cabernet Franc at Cheval Blanc is grown in clay soils, and Merlot in gravelly soils, 60% of the plantings are Cabernet Franc and 40% Merlot.

Grapes are harvested based on maturity parameters, the development and maturation is followed in the grapes for a couple of weeks before harvest date. Also, of interest is that the picking time is always 40-46 days after 1/2 veraison. Depending on year/climate, the grapes are harvested with sugars producing wine of 11.5 – 13% alcohol, pH 3.6-3.7 at harvest, with final pH in the wine 3.8-3.9. The maturity of the tannins is determined by tasting skins and optical density of skin extracts. The grapes are picked into plastic containers and sorted twice before fermentation. Sorting of premier clusters is done by approximately 8 people picking out approximately 70% of affected grapes and stem pieces. Some years, like apparently 2002, the pickers are asked to remove all affected berries already in the field.

Fermentation tanks are concrete and stainless steel - winemaker likes concrete better, as heat is retained and temperature more uniform through post-fermentation. The winemakers at Cheval Blanc strive to ferment the various lots and vineyard sites separately; no more than two lots are put in the same tank. The winemaking is “minimalist”, no enzymes; the must is inoculated with selected yeasts with pumpover -especially conscientiously the first three days. Temperature of must is approximately 20-22°C at start and increases to 30-32°C during fermentation. ML fermentation happens naturally in tanks with temp around 20°C. As soon as MLF finishes, wine is pumped into barrels, no blending done at this stage. Barrels are from several builders. The barrels have two outlets for removal of lees; on lees maturation of the wine is not part of the Cheval Blanc winemaking process. Blending of Cabernet Franc and Merlot happens in January - March, selection of premier Cru by expert panel. Wine is then transferred every 3 months with good aeration. 100% new French oak is used for the premier wine, 50% for second wine - petit Cheval. The blended wine is aged for 18-20 months. About three months before bottling, wine is fined with egg whites. The wine is not filtered.

Winemaking in the Vineyard: Water Stress. (Review 3 of 3 of C. B.)

Introduction

Much has been made of the French concept of “terroir” and this was the first experience many of us had had with the concept at first hand.

Kees van Leeuwen winemaker at Cheval Blanc, provided an in-depth discussion of the importance of understanding water availability and wine quality. Kees has a unique background, having a Ph.D. in hydrology, is an experienced winemaker, and thus is in a favorable position to study this aspect of “terroir” in fine wine making. The three soil types at Cheval Blanc formed the basis of discussion. The first is a terrace of tender rock indented by exposure to sandy soil on a clay sub-soil, the second, gravel on a clay sub-soil and the third, deep gravel. Only the deep gravel soils areas are not subjected to tile drainage procedures. The focus of the winegrower program is to balance the rate of maturity with the different soil types. In particular, as Merlot tends to ripen too early, and has been traditionally planted on gravel (against most of the local practice in the area!), it is generally planted on the poorer soils; i.e. gravel. Such soils undergo more water stress in dry years; in consequence the wines have low yields with more fruit aromas and harsher tannins. In dry years without drought stress, photosynthesis is extended near harvest and the resulting wines have velvety tannins and more powerful structure. Kees explained that over many years they were confident that quality and low water levels were directly related. Heat stress is not a favorable predictor of quality. Yields are also kept low through the use of 101-14 rootstock on Merlot plantings.

New Selections
Recent plantings directed at the replacement of 30-plus year-old vines is following a different approach. Merlot is now being planted on the sand/clay areas and Cabernet Franc on the gravel as it tends to be more water stress resistant than Merlot. Replacement Cabernet Franc vines have all been from their own stock as clonal selection in Bordeaux has been centered on Cabernet Sauvignon and Merlot and better Cabernet Franc clones are only now becoming available.

Trellis and Management Practices
 Traditional single Guyot training has been employed for over a century. Alternate buds are removed and nature seems to frequently remove additional buds, so that the crop load on the Cabernet Franc is no more than two tons/acre. New plantings are aimed at more fully filling out the trellis space: bilateral Guyot is now used routinely. Hedging is carried out 3-4 times per year, perhaps more for appearance than need. Canes were no more than 1.2 meters vertical. Row and vine spacing are traditionally tight at around 1.3 meters. Small rolling chairs aid in the hand working of these vines to avoid the traditional back bending seen in earlier years in Bordeaux.

The Vineyard and Winegrowing: please also see the two web-sites for additional information from the winery.

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