3 R e d W i n e P r o d u c t i o n in the C o a s t a l Counties o f California 1960-1980
Downloaded via TUFTS UNIV on July 7, 2018 at 09:44:00 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.
LOUIS P. MARTINI Louis M. Martini Winery, St. Helena, CA 94574 ost of the best California red table wines come from the coastal counMties of California. The counties north of San Francisco Bay generally
are considered to be the premier areas for the production of quality red wines. To help understand the reasons for this, a short review of the growing characteristics and history of these areas would be helpful. The padres first introduced the grape into California and planted it at their Mission sites as they progressed northward from San Diego. As indicated earlier (p. 8), a number of importations of vines from the wine growing areas of Europe were made into California. Those of Agoston Haraszthy were planted near the town of Sonoma, about fifty miles north of San Francisco. His and other importations helped lay the foundation for the wine industry of the coastal counties. Most of these varieties flourished in the soil and climate of Sonoma and soon spread throughout northern California. However, it was in the counties of Napa and Sonoma that the red table wine grapes were particularly well suited to the climate and soil of the area. The Climate The state of California has been divided into five climatic regions by Amerine and Winkler (I) according to the temperature accumulation above 10° C during the growing season of the grapevine. The coastal counties of California contain the three coolest regions. Grapes for red table wines generally do best in one of these three regions, depending upon the characteristics of the individual variety. Rainfall in the North Coast counties is sufficient (about 60-90 cm per year) to farm grapes on deep soils without irrigation. However, if water is available, it is desirable to have some irrigation to supplement natural rainfall, particularly in dry seasons. When properly applied, irrigation does not affect grape quality. Water sources are existing aquifers, mountain reservoirs, and reclaimed winery wastewater. Studies are being conducted now into the feasibility of using reclaimed municipal wastewater. Application in vineyards is generally either by permanent set or portable sprinklers or by 0
0097-6156/81/0145-0059$06.50/0 1981 American Chemical Society
Amerine; Wine Production Technology in the United States ACS Symposium Series; American Chemical Society: Washington, DC, 1981.
60
W I N E P R O D U C T I O N T E C H N O L O G Y IN T H E U N I T E D
STATES
drip. Fertilizers and pesticides also have been distributed successfully through irrigation systems. Water quality is generally good, except for a few localized problems with high boron and salt contents. In contrast to the North Coast counties, the Central Coast counties, south of San Francisco, generally do not receive enough rainfall to grow grapes economically without irrigation. In this latter area, high salt contents of well water and high winds during the daytime have presented problems that have been mitigated by specialized irrigation practices. The Soils Soil types in the coastal counties vary from deep rich loams to shallow clay-loams with underlying impervious clay or rocks. Well-drained, gravelly soils with good depth and moderate fertility are considered ideal for high quality red table wine grapes. They generally produce a moderate crop of very high quality grapes when the proper variety is planted to match the climate and exposure of the area. While climate is the dominant factor in producing quality grapes, soil type should not be ignored. Fertilization generally is used very sparingly in coastal vineyards. No real correlation between fertilization and crop response has been determined. Cook (2) indicated that vine requirements were determined best by leaf petiole analyses. Excessive fertilization resulting in vigorous vine growth must be avoided, however, as this may affect berry set and thus reduce crop. Mountain vineyards often are fertilized to assure a good covercrop for erosion control. The Grapes Kasimatis et al. (3) described the principal grape varieties grown in the North Coast counties of California. They are the Pinot noir, Petite Sirah, Zinfandel, Merlot, Carignane, Cabernet Sauvignon, and Gamay. These are listed in the approximate order of ripening from early September through late October. Each generally is planted in the climatic region most suitable to it; however, since lines between regions are not identified clearly, considerable overlapping of maturity dates can be found among the varieties. Fairly large differences in the quality of wines made from the same variety grown on different soils and microclimates have been observed by the author. Areas such as the north or south side of a mountain or near the mouth of a canyon have been observed to make considerable differences in the time of maturity and the balance of sugar and acid in the grapes. Work such as that reported by Kliewer (4), and still under way, may explain the reasons for some of these differences in the future. The importance of crop level should not be overlooked. Differences in microclimates, soil types, and general climatic conditions are difficult to measure and relate to grape quality. Most of the advancements in adapting the right grape to the right location have come about by Amerine; Wine Production Technology in the United States ACS Symposium Series; American Chemical Society: Washington, DC, 1981.
3.
MARTINI
Red Wine Production
61
trial and error. As knowledge has accumulated, each generation has done a better job of fine tuning its planting practices. With the normal cycle of a grapevine being about thirty years, progress is very slow, but it is positive and very encouraging. Spring frosts are a problem in most of the wine growing areas of the North and Central Coast counties. This is especially true of the lower lying areas. Lider (5) found no satisfactory way to treat frosted vines so that they could recover and produce an economic crop. Hence, it is essential that all vineyards in the areas subject to frost have some protection. Water from overhead sprinklers delivered at approximately fifty gallons per acre per minute has proved to be the best method. However, if enough water is not available, wind machines or a combination of wind machines and orchard heaters have proved effective for most areas. Recent advances in oil prices may well make the heater-wind machine combination too expensive to operate in the future. Practically all vineyards in the North Coast are planted on rootstocks resistant to the plant louse phylloxera, which is endemic to the area. This is not yet a problem to the new growing areas of the Central Coast and most of their vineyards are planted on their own roots. Eventually, these areas also will have to revert to rootstocks unless science finds an acceptable way of destroying or preventing the spread of phylloxera in the interim. Powdery mildew (oïdium) is the most serious fungus disease of grapes and must be controlled in all areas of California with properly timed application of sulfur dust or sprays. There are a number of other diseases and pests that attack grapevines and fruit but these usually are localized to given areas or occur intermittently only. Various sprays, dusts, or biological control methods are used to control them. Viruses that diminish vine vigor and fruit maturity are prevalent in older vineyards but have been practically eliminated from newer vineyards by a grape certification program started about twenty years ago. Most vineyards developed in the past decade are practically disease-free. This has been a major factor in raising the productivity of all varieties as well as opening up areas for planting that would have been marginal with diseased vines. It is accepted generally that crop level has an effect on grape quality. It has been the author's experience that the best quality years for red table wines have been associated with lower crops, although high quality wines have been made in years when a full crop could be brought to proper maturity. A bumper crop usually results in wines of lesser quality. Within limits, crop levels can be controlled by pruning practices. These usually are based upon the growth the vine made in the previous year. The more growth the vine made, the more buds are left to produce fruit and, hence, the larger the crop. If the vine is allowed to produce more fruit than it can bring successfully to maturity, it is overcropped. This produces inferior fruit and tends to weaken the vine. Undercropping is also undesirable as it may produce excessive vegetative growth and an uneconomical crop. ThereAmerine; Wine Production Technology in the United States ACS Symposium Series; American Chemical Society: Washington, DC, 1981.
62
W I N E P R O D U C T I O N T E C H N O L O G Y IN T H E U N I T E D
STATES
fore, the balancing of the crop and vegetative growth by judicious pruning is essential to producing quality wines. In recent years, some growers have been experimenting with improved trellising techniques to expand the vine surface and leaf exposure to allow the vine to bring a larger crop into full maturity. A fair degree of success has been observed in some varieties for certain areas. Production Trends In the late sixties and early seventies, the apparent demand for premium red table wine grape varieties was so great that many varieties were planted indiscriminately, with little regard to location or actual consumer demand. Experience has shown that actual demand is always lower than apparent demand because of the tendency of wholesalers, retailers, and consumers to hoard a product they think will be in short supply. The problems of overproduction came about in the late seventies simply because too many red grapes were planted in the early seventies. Table I shows the bearing and nonbearing acreage of the principal red table wine varieties for the major grape growing counties of the North Coast and Central Coast for 1971 and 1978. Figure 1 illustrates the comparative trends of red and white wine sales for the state of California and the total acreage of red table and white table wine grapes in California. It is clear that in the Table I. Bearing and Nonbearing Acreage of Red Wine Crapes in the North Coast and Central Coast* Regions 0
7
Bearing 1971 North Coast Central Coast North Coast Central Coast North Coast Central Coast North Coast Central Coast North Coast Central Coast North Coast Central Coast North Coast Central Coast
Cabernet Sauvignon Cabernet Sauvignon Carignane Carignane Gamay (Napa) Gamay Beaujolais Gamay (Napa) Gamay (Beaujolais) Pinot noir Pinot noir Petite Sirah Petite Sirah Zinfandel Zinfandel Merlot Merlot Total
1978
2932 12,083 9263 808 4733 3866 279 332
Total
Nonbearing
1971
1977
1971
1978
1971 1390 70 0
725 0 10 0
4894 12,808 2198 9263 4803 3876 332 279
1344
3904
794
117
2138
4021
410 1149 1053 2940 170 5234 868 119 120
3444 6064 4002 2528 2628 7749 5017 1555 1559
847 699 263 52 324 255 475 112 286
0 98 2 155 31 700 71 97 58
1257 1848 1316 2992 494 5489 1343 231 406
3444 6162 4004 2683 2659 8449 5088 1652 1617
22,203 63,941
7538
2064
29,801 66,005
^Counties of: Alameda, Lake, Marin, Napa, Sonoma, Mendocino, Contra Costa ''Counties of: Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Clara, Santa Cruz
Amerine; Wine Production Technology in the United States ACS Symposium Series; American Chemical Society: Washington, DC, 1981.
3.
MARTINI
1969
Red Wine Production
63
boooooooooooooooooooooooo^
[(>Ο
