The system
The system is based on both the hypothesis and observations that grapevines do not grow if the temperature is below 50 °F (10 °C). [2] Each day during the growing season are assigned growing degree-days according to the amount that the day's average temperature exceeds this threshold. This is assumed under the system to be April 1 through October 31 in the Northern Hemisphere, October 1 through April 30 in the Southern Hemisphere. One degree day per degree Fahrenheit over 50 °F, or with SI units, degrees Celsius over 10 °C is used.
All days during the growing season are then added up, all negative values are set to zero, with the sum of the growing degree-days used to determine the region's classification in the original Winkler index as follows:
The system was originally developed for and is used officially in California and was based on the general ripening capabilities and wine styles [1] [2] that can be achieved in the climate due to heat accumulation (growing degree-days). The general ripening capabilities include hybrid grape varieties through early season, mid-season, and late season ripening V. Vinifera and even table grapes in the warmest areas of Region V. The general wine styles include lighter, more subtle wines with lower alcohol and brighter fruit aromas and flavors, including Champagne and other sparkling wines, found in cooler climates (Regions Ia, Ib, II and lower III) to bolder, bigger wines often with higher alcohol and lush, darker fruit aromas and flavors that are found in warmer climates (Region III, IV and V). Region V was stated as also having a tendency to be more suitable to higher production wines, Sherry and other fortified wines. [1] [2]
One issue with the original work done by Amerine and Winkler [1] was that it did not specify a lower class limit for Region I (originally 2500 or less) or an upper class limit for Region V (originally 4000 or greater). Subsequent research [3] [4] using high resolution spatial climate data identified these limits for California, Oregon, Washington and Idaho, along with Australia. The results provided a lower bound to Region I of 1500 °F units (850 °C units) and an upper bound to Region V of 4900 °F units (2700 °C units). Additional research in other wine regions found that Region I was best divided into a Region Ia (very early ripening varieties, mostly hybrid grapes) and Region Ib (early ripening varieties, mostly V. Vinifera). [5] [6]
The Winkler Index is also widely used in many other growing regions in the United States, such as Oregon and Washington, along with Canada, South America, Australia, New Zealand, South Africa, and Europe. However, it is less widely used in Europe where the Huglin index [7] is favored. The Huglin index uses a similar formula but gives more weight to maximum temperatures and uses an adjustment for longer day lengths found at higher latitudes. [7] It is also functionally similar to growing season average temperatures (simple average of temperatures across the seven month growing season). [3] [4] [5]
Application
The table below provides examples of the ripening and wine style concept used in the application of the Winkler Index for numerous wine regions globally. Region Ia are the coolest areas with known regions including Champagne, Central Otago, and Valais. Region Ia also includes numerous newer regions growing grapes and making wine including southern England, areas in northern Europe, Nova Scotia, and southern areas of Chile and Argentina. Region Ia areas ripen a range of hybrid grapes and some very early ripening V. Vinifera.
Region Ib is slightly warmer, can ripen early varieties such as Chardonnay, Pinot noir, Sauvignon blanc or Riesling with characteristic locations within the Rhine and Mosel valleys, Burgundy and the Loire Valley, or the Willamette Valley in Oregon as good examples. Region II includes cooler locations within areas such as Bordeaux, Coonawarra, and Valle de Curicó in Chile. Warmer areas in these wine regions fall in a Winkler Region III as do much of the Northern Rhône, Rioja, Umbria, and the Margaret River.
Region IV includes portions of the Napa Valley, Stellenbosch, Corsica, Tuscany, and Alentejo where the warmer climates allow for the ripening of later varieties such as Cabernet sauvignon, Sangiovese, and Syrah. The warmest areas are found in Region V and include areas in the central valley of California, inland Australia and wine producing regions in Morocco, Madeira, Apulia, and Jerez.
Table of wine regions in various countries worldwide. The city represents the location of the weather station that was used to calculate the growing season average temperatures (GST) and growing degree-days for classifying into Winkler Regions. The data represent either the 1981-2010 climatological normals or period of record for that station. Data come from the World Atlas of Wine [8] and a publication [9] on cool climate regions from the International Cool Climate Symposium (http://www.iccws2016.com/).| Country | Wine Region | City | GST (°F) | GDD (°F units) | Winkler Region |
|---|
| Argentina | Rio Negro | Bariloche | 55.6 | 1194 | Region Ia |
| Chile | Lake District | Puerto Montt | 55.8 | 1233 | Region Ia |
| Denmark | | Aalborg | 55.8 | 1233 | Region Ia |
| Washington | Puget Sound | Port Angeles | 56.1 | 1310 | Region Ia |
| Germany | Ruwer | Kasel | 56.9 | 1472 | Region Ia |
| Sweden | | Gothenborg | 57.0 | 1502 | Region Ia |
| England | Kent | East Malling | 57.3 | 1562 | Region Ia |
| Canada | Nova Scotia | Kentville | 57.4 | 1579 | Region Ia |
| Michigan | Leelanau Peninsula | Traverse City | 57.9 | 1695 | Region Ia |
| Australia | Tasmania | Launceston | 58.0 | 1709 | Region Ia |
| New Zealand | Central Otago | Queenstown | 58.1 | 1733 | Region Ia |
| Netherlands | | Maastricht | 58.3 | 1772 | Region Ia |
| France | Champagne | Reims | 58.4 | 1805 | Region Ia |
| Austria | Kremstal | Krems | 58.5 | 1821 | Region Ia |
| Poland | Lubuskie | Zielona Góra | 58.6 | 1849 | Region Ia |
| Switzerland | Valais | Sion | 58.7 | 1871 | Region Ia |
| England | Sussex | Eastbourne | 58.8 | 1887 | Region Ia |
| Canada | Okanagan Valley | Vernon | 59.0 | 1926 | Region Ia |
| Germany | Rhine Valley | Geisenheim | 59.4 | 2003 | Region Ib |
| New Zealand | Marlborough | Blenheim | 59.7 | 2075 | Region Ib |
| Canada | Niagara Peninsula | St. Catharines | 60.1 | 2152 | Region Ib |
| France | Burgundy | Dijon | 60.3 | 2196 | Region Ib |
| Spain | Ribera del Duero | Valladolid | 60.3 | 2211 | Region Ib |
| France | Alsace | Colmar | 60.4 | 2218 | Region Ib |
| Hungary | Tokaj | Tokaj | 60.4 | 2229 | Region Ib |
| Australia | Tasmania | Hobart | 60.4 | 2234 | Region Ib |
| Oregon | Willamette Valley | McMinnville | 60.6 | 2273 | Region Ib |
| Romania | Zeletin | Bacău | 60.7 | 2295 | Region Ib |
| California | Central Coast | Santa Maria | 60.7 | 2296 | Region Ib |
| France | Loire Valley | Nantes | 61.0 | 2355 | Region Ib |
| Germany | Baden | Freiburg | 61.2 | 2403 | Region Ib |
| France | Savoie | Chambéry | 61.5 | 2454 | Region Ib |
| Ukraine | Crimea | Simferopol | 61.7 | 2504 | Region II |
| Australia | Coonawarra | Coonawarra | 61.9 | 2553 | Region II |
| Spain | Rias Baixas | Vigo | 62.2 | 2619 | Region II |
| New Zealand | Hawke's Bay | Napier | 62.9 | 2768 | Region II |
| Australia | Adelaide Hills | Lenswood | 63.2 | 2817 | Region II |
| Portugal | Douro Valley | Vila Real | 63.4 | 2861 | Region II |
| Chile | Valle de Curicó | Curicó | 63.4 | 2864 | Region II |
| Italy | Piedmont | Torino | 63.8 | 2958 | Region II |
| France | Bordeaux | Merignac | 63.8 | 2961 | Region II |
| Washington | Columbia Valley | Prosser | 64.0 | 2993 | Region II |
| Italy | Alto Adige | Bolzano | 64.1 | 3016 | Region III |
| France | Northern Rhône | Valence | 64.1 | 3027 | Region III |
| Italy | Friuli | Udine | 64.4 | 3082 | Region III |
| Italy | Umbria | Perugia | 64.6 | 3132 | Region III |
| Spain | Rioja | Logrono | 64.8 | 3167 | Region III |
| California | Sonoma Valley | Sonoma | 64.9 | 3189 | Region III |
| Bulgaria | Thracian Valley | Plovdiv | 64.9 | 3192 | Region III |
| Russia | Krasnodar | Krasnodar Krai | 65.0 | 3219 | Region III |
| Australia | Yarra Valley | Healesville | 65.5 | 3325 | Region III |
| California | Mendocino | Ukiah | 65.8 | 3384 | Region III |
| Virginia | Monticello | Charlottesville | 66.1 | 3442 | Region III |
| Australia | Margaret River | Margaret River | 66.2 | 3472 | Region III |
| Italy | Verona | Verona | 66.4 | 3509 | Region IV |
| France | Languedoc | Béziers | 66.7 | 3577 | Region IV |
| California | Napa Valley | St Helena | 66.8 | 3601 | Region IV |
| California | Northern Sonoma | Healdsburg | 67.1 | 3650 | Region IV |
| France | Southern Rhône | Avignon | 67.4 | 3725 | Region IV |
| South Africa | Stellenbosch | Nietvoorbij | 67.5 | 3751 | Region IV |
| Australia | Barossa Valley | Nuriootpa | 67.6 | 3756 | Region IV |
| France | Roussillon | Perpignan | 67.6 | 3769 | Region IV |
| France | Corsica | Bastia | 67.6 | 3775 | Region IV |
| Spain | Catalunya | Reus | 68.0 | 3845 | Region IV |
| Portugal | Alentejo | Evora | 68.1 | 3874 | Region IV |
| Italy | Tuscany | Firenze | 68.3 | 3907 | Region IV |
| Portugal | Estremadura | Lisbon | 68.7 | 3995 | Region IV |
| California | Lodi | Lodi | 68.7 | 4005 | Region V |
| Japan | Yamanashi | Kofu | 69.3 | 4140 | Region V |
| Morocco | Meknes-Tafilalet | Meknes | 69.4 | 4149 | Region V |
| Portugal | Madeira | Funchal | 69.8 | 4243 | Region V |
| Italy | Apulia | Brindisi | 69.9 | 4250 | Region V |
| Greece | Patras | Patras | 70.1 | 4292 | Region V |
| Australia | Hunter Valley | Cessnock | 71.0 | 4497 | Region V |
| Spain | Jerez | Jerez de la Frontera | 71.4 | 4575 | Region V |
Issues and limitations
There are numerous issues and limitations associated with the use of growing degree-days. First, the Winkler index and its classification of climate regions by growing degree-days only describe one aspect of an area's climate—mean daily temperature. Many other important factors which contribute to a region's suitability for viticulture (and its terroir) are excluded; among them sun exposure, latitude, precipitation, soil conditions, and the risk of extreme weather which might damage grapevines (e.g., winter freezes, spring and fall frosts, hail, etc.). [6]
As originally developed the climates of California were defined for relatively large areas using only one or two climate stations. This macroscale approach will invariably not capture the microscale influences that are an important aspect of growing any crop. To address these issues research has been increasingly using spatial climate data to better depict within region and even within vineyard differences in climate [6] and therefore ripening and wine style potential.
To create spatially appropriate climate data, numerous stations and/or sensors are used to collect data which can then be interpolated over the landscape due to known interactions with elevation, aspect, slope, and distance to the coast or other water bodies using Geographic Information Systems (GIS). [10] Instead of depicting a region as all one Winkler region (Napa Valley AVA being a Region III for example), spatial data summaries [3] show the Napa Valley having a full range of Winkler regions, 12% a Region II, 56% a Region III, and 30% a Region IV (whereas the table above shows one station in Napa, St. Helena as being a Region IV).
Other significant differences exist depending on the time period of the data and formula used for calculating growing degree-days. First, to be comparable growing degree-day numbers from various sources need to come from the same time period. [3] Due to both a variable climate and climate change, a comparison of a ten-year period from the 1970s and the 2000s would be inappropriate as the variation and trends over time would make them incomparable. A sufficient time period is suggested to allow the averaging to smooth out some of the variability. The standard time period in use is the climatological normal period of 30 years, [11] however if 30 years of data is not available then at the minimum five years should be used.
However a five-year period is not directly comparable to a 30-year period. How data are averaged (i.e., hourly, daily, or monthly) is also very important. While weather stations today can average data to an hour, a minutes or even seconds, historical data used to calculate growing degree-days has been done mostly on daily or monthly averages (the table above was done using monthly climatological normals). Shorter term averaging to minutes, or more commonly hourly, arguably better reflects the true thermal effects on the crops, but will result in growing degree-day values that are lower than both daily and monthly. [3] [12] Monthly averaged data can be very problematic as it can underestimate heat accumulation during the first and last months of the growing season. Therefore, it is paramount that one know the time period that the growing degree-day values are calculated from so as to be comparable.
The Winkler index uses the standard method of calculating growing degree-days in viticulture and is based on using a base temperature of 50 °F (10 °C) with no upper temperature cut-off. The first issue is that 50 °F (10 °C) is not likely the best base temperature even though it is the most commonly used value. Even the early research on this topic stressed that the base temperature threshold for accumulation for early versus late budding varieties is likely strongly cultivar specific. [1] [2] Various research worldwide has pointed to base temperatures ranging from 39 to 45 °F (4 to 7 °C), but there has been little confirmation of these thresholds across numerous wine regions and for a wider range of varieties. [13]
At the other end of the formula, the calculation for growing degree-days used in viticulture and wine production does not normally use an upper cut-off. Conceptually an upper cut-off would be applied if the plant system stopped being photosynthetically active at some point due to heat stress from high temperatures. While this may be proven for some crops, there is not a universal number for an upper threshold for grapes so the majority of the published data for comparison purposes in viticulture and wine production does not limit maximum temperatures. [14] This issue is problematic because many weather stations today have integrated the corn growing degree-day method in their software. The corn growing degree-day method uses both a base temperature adjustment and an upper threshold, [15] neither of which are common in viticulture and wine production use, and can confound any comparison with published data using the simple average method. [3]
Furthermore, more complex climate indices have been introduced to address perceived shortcomings in the Winkler index including the Huglin Index, [7] the Biologically Effective Degree-Day Index, [16] and the Multicriteria Climatic Classification system (Geoviticulture MCC). [17] These indices attempt to account for day length and solar, frost, and drought variability that can be found in different locations. Each have been used in various research settings, [3] but have some limitations to the general user in that some variables needed to calculate the indices are not readily available from all weather/climate stations and/or to the general public.
Overall each of these issues needs to be carefully considered when comparing growing degree-day values from published data in magazines, books, scientific articles, and even from growers in the same region.
Vitis vinifera, the common grape vine, is a species of flowering plant, native to the Mediterranean region, Central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran. There are currently between 5,000 and 10,000 varieties of Vitis vinifera grapes though only a few are of commercial significance for wine and table grape production.
Viticulture or winegrowing is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of Vitis vinifera, the common grape vine, ranges from Western Europe to the Persian shores of the Caspian Sea, the vine has demonstrated high levels of adaptability to new environments, hence viticulture can be found on every continent except Antarctica.
Tempranillo is a black grape variety widely grown to make full-bodied red wines in its native Spain. Its name is the diminutive of the Spanish temprano ("early"), a reference to the fact that it ripens several weeks earlier than most Spanish red grapes. Tempranillo has been grown on the Iberian Peninsula since the time of Phoenician settlements. It is the main grape used in Rioja, and is often referred to as Spain's noble grape. The grape has been planted throughout the globe's wine regions.
Millerandage is a potential viticultural hazard problem in which grape bunches contain berries that differ greatly in size and, most importantly, maturity. Its most common cause is cold, rainy or otherwise bad weather during the flowering stage of the vines though other factors, such as boron deficiency or fanleaf degeneration, may also play a role.
Michigan wine refers to any wine that is made in the state of Michigan in the United States. As of 2020, there were 3,375 acres (1,366 ha) under wine-grape cultivation and over 200 commercial wineries in Michigan, producing 3 million US gallons (11,000,000 L) of wine. According to another count there were 112 operating wineries in Michigan in 2007.
Washington wine is a wine produced from grape varieties grown in the U.S. state of Washington. Washington ranks second in the United States in the production of wine. By 2017, the state had over 55,000 acres (220 km2) of vineyards, a harvest of 229,000 short tons (208,000 t) of grapes, and exports going to over 40 countries around the world from the 940+ wineries located in the state. While there are some viticultural activities in the cooler, wetter western half of the state, the majority (99.9%) of wine grape production takes place in the shrub-steppe eastern half. The rain shadow of the Cascade Range leaves the Columbia River Basin with around 8 inches (200 mm) of annual rain fall, making irrigation and water rights of paramount interest to the Washington wine industry. Viticulture in the state is also influenced by long sunlight hours and consistent temperatures.
The Columbia Valley AVA is an American Viticultural Area which lies in the Columbia River Plateau, through much of central and southern Washington State, with a small section crossing into the neighboring state of Oregon. The AVA includes the drainage basin of the Columbia River and its tributaries through much of Washington. Allen Shoup, president of Washington State's largest winery Chateau Ste. Michelle, understood the importance of obtaining appellation status for Washington State to grow the reputation of the vineyards. He hired Drs. Wade Wolfe and Walter Clore to petition the federal government for appellation status, a request that was granted in 1984. The Columbia Valley AVA is the largest wine region in the state of Washington, including over 11,000,000 acres (4,500,000 ha), of which over 50,000 acres (20,000 ha) are planted in vineyards. The Columbia Valley AVA includes 99% of the total vineyard area planted in the state of Washington. Grapes grown here include Cabernet Sauvignon, Merlot, Chardonnay, Riesling, Syrah, Pinot Gris, and Sauvignon blanc. Concord grapes and other Vitis labrusca grapes are grown in the region as well. The unique climates of the area allow the Columbia Valley to produce wines that are very fruit-forward, like California wine, but which also retain some of the balance and structure of European wine.
Texas has a long history of wine production. The sunny and dry climate of the major winemaking regions in the state have drawn comparison to Portuguese wines, in addition to other regions in Europe like Spain, France, and Italy. Some of the earliest recorded Texas wines were produced by Spanish missionaries in the 1650s near El Paso. Texas ranked as the fifth largest wine producing state by 2019.
The Mendocino County wine is an appellation that designates wine made from grapes grown mostly in Mendocino County, California. The region is part of the larger North Coast AVA and one of California's largest and most climatically diverse wine growing regions. Mendocino County is one of the northernmost commercial wine grape regions in the state with two distinct climate zones separated by the Mendocino Range. Ten American Viticultural Areas have been designated within Mendocino County. Mendocino is one of the leading wine growing regions for organically produced wine grapes. Nearly 25% of the acreage in Mendocino County is grown organically. In 2004, the residents of the county voted to become the first GMO-free county in the United States in an initiative that was supported by many of the county's largest wineries. The county's widespread focus on organic viticulture has inspired journalists to describe it as "California's organic wine Mecca".
Mississippi wine refers to wine made from grapes grown in the U.S. state of Mississippi. The hot and humid climate of Mississippi makes it very difficult to cultivate vitis vinifera or French hybrid grapes. The three commercial wineries in Mississippi focus almost entirely on the Muscadine grape, a variety also used for non-alcoholic grape juices, jams, and jellies. Most of the Mississippi Delta AVA, a designated American Viticultural Area, lies within the state boundaries of Mississippi.
The modern Indian Wine market is small but growing; annual per capita consumption of wine in the country is a mere 9 milliliters, approximately 1/8000th that of France. The main reason for this can be attributed to the fact that Indians preference for hard liquor and beer boasts nearly 98% of market share whereas wine with low ABV only has 2% market share. The viticulture in India has a long history dating back to the time of the Indus Valley civilization when grapevines were believed to have been introduced from Persia. Winemaking has existed throughout most of India's history but was particularly encouraged during the time of the Portuguese and British colonization of the subcontinent. The end of the 19th century saw the phylloxera louse take its toll on the Indian wine industry followed by religious and public opinion moving towards the prohibition. Following the country's independence from the British Empire, the government encouraged vineyards to convert to table grape and raisin production. In the 1980s and 1990s, a revival in the Indian wine industry took place as international influences and the growing middle class started increasing demand for the beverage. By the turn of the 21st century, demand was increasing at a rate of 20-30% a year. The city of Nashik in the state of Maharashtra is called the "Wine Capital of India."
The Finger Lakes AVA is an American Viticultural Area located in Upstate New York, south of Lake Ontario. It was established in 1982 and encompasses the eleven Finger Lakes, but the area around Canandaigua, Keuka, Seneca, and Cayuga Lakes contain the vast majority of vineyard plantings in the AVA. Cayuga and Seneca Lakes each have their own American Viticultural Areas completely contained within the Finger Lakes AVA. The Finger Lakes AVA includes 11,000 acres (4,452 ha) of vineyards and is the largest wine-producing region in New York State.
The annual growth cycle of grapevines is the process that takes place in the vineyard each year, beginning with bud break in the spring and culminating in leaf fall in autumn followed by winter dormancy. From a winemaking perspective, each step in the process plays a vital role in the development of grapes with ideal characteristics for making wine. Viticulturalists and vineyard managers monitor the effect of climate, vine disease and pests in facilitating or impeding the vine's progression from bud break, flowering, fruit set, veraison, harvesting, leaf fall and dormancy-reacting if need be with the use of viticultural practices like canopy management, irrigation, vine training and the use of agrochemicals. The stages of the annual growth cycle usually become observable within the first year of a vine's life. The amount of time spent at each stage of the growth cycle depends on a number of factors-most notably the type of climate and the characteristics of the grape variety.
This glossary of viticultural terms list some of terms and definitions involved in growing grapes for use in winemaking.
Irrigation in viticulture is the process of applying extra water in the cultivation of grapevines. It is considered both controversial and essential to wine production. In the physiology of the grapevine, the amount of available water affects photosynthesis and hence growth, as well as the development of grape berries. While climate and humidity play important roles, a typical grape vine needs 25-35 inches of water a year, occurring during the spring and summer months of the growing season, to avoid stress. A vine that does not receive the necessary amount of water will have its growth altered in a number of ways; some effects of water stress are considered desirable by wine grape growers.
In viticulture, the climates of wine regions are categorised based on the overall characteristics of the area's climate during the growing season. While variations in macroclimate are acknowledged, the climates of most wine regions are categorised as being part of a Mediterranean, maritime or continental climate. The majority of the world's premium wine production takes place in one of these three climate categories in locations between the 30th parallel and 50th parallel in both the northern and southern hemisphere. While viticulture does exist in some tropical climates, most notably Brazil, the amount of quality wine production in those areas is so small that the climate effect has not been as extensively studied as other categories.
Gregory V. Jones is an American research climatologist specializing in the climatology of viticulture, with a focus on how climate variation influences vine growth, wine production, and the quality of wine produced. Jones serves as the CEO of Abacela Vineyards and Winery in Roseburg, Oregon. Previously he served as the Director of the Center for Wine Education and is Professor of Environmental Studies at Linfield College in McMinnville, Oregon and as the Director of the Division of Business, Communication and the Environment at Southern Oregon University in Ashland, Oregon and was Professor in the university's Environmental Science and Policy Program.
Pierre Huglin developed a bioclimatic heat index for vineyards, the Huglin heat sum index in which the temperature sum over the temperature threshold of 10 °C is calculated and then summed for all days from beginning of April to end of September. The calculation uses both the daily average temperatures and the maximum temperatures and slightly modifies the calculated total according to latitude. Each grape variety needs a certain amount of heat in order to be cultivated successfully in the long term in a given area. The calculated heat sums, which are based on data from weather stations or from climate models, differ in that they are too low compared to the actual values in the vineyards. The index does not take into account e.g. thermally favoured hillsides where temperature values may be higher by about 1.5 °C to 2 °C.
San Luis Obispo Coast and SLO Coast identify the sixteenth American Viticultural Area (AVA) within San Luis Obispo County, California. It was established by the Alcohol and Tobacco Tax and Trade Bureau (TTB) on April 8, 2022, becoming the state's 143rd official AVA. The area encompasses over 480,585 acres (750.914 sq mi) nestled between the Santa Lucia mountains and the Pacific coastline stretching about 70 miles (110 km) from Ragged Point southbound on the Pacific Coast Highway (PCH) and Highway 101 to the outskirts of Santa Maria at the intersection of State Highway 166 and Highway 101. It includes the coastal communities of San Simeon, Cambria, Cayucos, Morro Bay, Avila Beach, Pismo Beach, Arroyo Grande and Nipomo while encompassing the county seat of San Luis Obispo. The TTB approved the petition's two names, "San Luis Obispo Coast" and "SLO Coast", to identify the viticultural area's description and wine labeling. The term "SLO" is a historical and commonly used reference for the county and city initials as well as a description of the region's relaxed culture. The new AVA overlaps the previously established Edna Valley and Arroyo Grande Valley viticultural areas. There are over 50 wineries and an estimated 78 commercial vineyards cultivating approximately 3,942 acres (1,595 ha) with a majority of the vineyards located within 6 miles (9.7 km) of the Pacific Ocean defining an area whose grapes and wines represent it. Cool weather varietals like Pinot Noir and Chardonnay are commonly grown while lesser varietals Sauvignon Blanc, Gewürztraminer and Gruner Veltliner also thrive.
Monterey County wine is a appellation that designates wine made from grapes grown in Monterey County, California which lies entirely within the expansive multi-county Central Coast viticultural area. County names in the United States automatically qualify as legal appellations of origin for wine produced from grapes grown in that county and do not require registration with the Alcohol and Tobacco Tax and Trade Bureau (TTB). TTB was created in January 2003, when the Bureau of Alcohol, Tobacco and Firearms, or ATF, was extensively reorganized under the provisions of the Homeland Security Act of 2002.
