WSET D3 - California Flashcards
Summerise the history of California wine industry.
over 80% all US wines. State alone is world’s 4th largest producer after Italy, France and Spain. Vineyards throughout the state; along Pacific coastline, in interior Central Valley, and up into Sierra Nevada foothills. State’s AVAs can be grouped into North Coast, Central Coast, Inland Valleys (including Central Valley), Sierra Foothills and Southern California.
Grapes initially introduced by Spanish missionaries who planted at missions they established along California coast as far north as Sonoma Valley. Most grapes used to make altar wine and sweet fortified wine. Plantings increased during 1849 Gold Rush and its concurrent population increase. By late 19th century, many regions producing wines, and a centre of wine research and education at University of California established.
1890s, overplanting led to a significant drop in grape and wine prices, making it difficult for producers to survive. Shortly followed by Prohibition, 1920 to 1933, stopped manufacture, transportation, sale and possession of alcohol beverages hence devastated industry.
1930s to the 1960s, California wine industry rebuilt itself. mid-20th century, consumer preferences mainly for M-sweet or sweet wines and many wines named after famous European regions such as ‘Chablis’, ‘Burgundy’ or ‘Rhine’, though styles often bared no resemblance. (Established brands still able to use such names if sold in domestic market, seen on some inexpensive, high-volume brands.) As US wine trade evolved, wines started to be labelled with descriptions such as ‘red table wine’ then, promoted heavily by quality-focused vintner Robert Mondavi, with name of grape variety and a specific origin.
Within mid- to late 20th century, Chardonnay and CS grew rapidly quickly became two predominant varieties. Same period, significant improvements made in grape growing and winemaking, many pioneered by leading winemaker and consultant André Tchelistcheff (temperature-controlled fermentation, better winery hygiene and techniques to prevent various diseases and frost damage).
1976, a France versus California blind tasting held in Paris, 2 California wines received top scores – 1973 Stag’s Leap Wine Cellars Cabernet Sauvignon and 1973 Chateau Montelena Chardonnay, bringing new attention and growth to California wine trade. More vineyards were planted, many using new AXR1 rootstock, give vines with higher yields than traditional rootstocks. However, it had some V. vinifera ancestry in its DNA, quickly proved unsuitable when phylloxera attack California vineyards in 1980s. Large-scale planting required, however, from this came opportunity to re-evaluate site selection, choice of planting material and canopy management, in many areas with a focus on quality rather than quantity.
1990s saw rise in deeply coloured, highly concentrated and high alcohol reds response to both consumer demand and critical acclaim. Whites similarly in a very ripe style with high new oak. Trend now largely passed, recent years California’s wine production been more diverse and of higher quality. There is greater concentration on matching grape variety to regional or site climate and soil, higher number professionally trained winemakers, a highly-regarded local wine researchcentre located in Davis and an ever-greater interest in experimenting with wide range varieties, winemaking techniques and wine styles.
What’s the climate like?
2 key influences are cold Pacific Ocean and ranges of mountains run along state.
Ocean influence: combination of California current, bringing water from north, and upwelling (process whereby deep cold water rises to surface) along west coast means coastal waters ]much colder than east coast. Vineyards without exposure to the ocean due to mountain protection are warm or even hot, whereas those with most exposure gain a significant cooling influence. The topography of the land is much more influential than the degrees latitude, with some of the coolest areas also being some of the most southerly.
In general, the Coast Ranges, that start in the far north of the state and run down to Santa Barbara County, provides some shelter from the ocean, however, gaps within these ranges, usually where river valleys break through, mean that ocean influence can reach further inland. As the land warms during the day, the air above it rises and pulls in cooler air from the coast during the afternoons and evenings, giving a high diurnal range. This air movement cools
the vineyards, reduces risk of fungal diseases and frosts, and in some places can be strong enough to cause the vines’ stomata to close and slow ripening in this way (as well as by lowering temperatures).
Fog can form in the afternoons and often can last into the morning, cooling but also reducing exposure to sunshine in those areas that are most affected. California’s latitudesare relatively low for a wine region (approximately 32–42° N) meaning when the fog burns off, sunlight is intense.
Altitude can be a cooling influence in some areas. In the majority of cases, these vineyards are situated above the layer of fog, so although altitude may lead to lower temperatures, these areas do gain long hours of intense sunlight which can lead to greater levels of colour and tannins in black grapes.
Areas without the influence of the coast or altitude can be much warmer. The largest of these areas are in the Sacramento and San Joaquin Valleys, often termed the Central Valley, where much of the grapes destined for inexpensive, high-volume wines are grown.
The overall climate could be described as Mediterranean without the marked contrasts in seasonal temperatures of a continental climate. The growing season in most of the regions is relatively dry. Dry autumns can extend the viable growing season, helpful in the coolest regions.
What’s the vineyard management like?
The 1990s saw large-scale vineyard replanting, caused by the presence of phylloxera, Pierce’s disease and increased understanding of vineyard management. Many vineyards changed from a relatively uniform way of planting and training – generally low-density, high- yielding vines pruned and trained either to replacement-cane or cordon – to be replanted with different densities, training and trellising techniques and a variety of planting materials. Greater attention was paid to matching rootstock to the growing environment and to grape growers’ aims. Attention to the site and the vine has increased even further in the 21st century with increased focus on precision viticulture.
Traditionally, California has benefitted from plentiful, skilled Mexican labour. However, ongoing federal policies on illegal immigration and work permits have led to a reduction in this labour force over recent years. Although vineyards in certain areas, such as the Central Valley, have long been set up for mechanization, an increasing number of vineyards throughout the state are now using machinery where topography allows.
Lack of rainfall during the growing season means that irrigation is installed in many vineyards. Drought has been a problem in recent years and has seen groundwater supplies dramatically decrease, leading to tensions between various agricultural businesses as well as residents in certain areas. Spurred by the drought, local water sustainability agencies have
been put in place to create and enforce water management schemes, leading to greater monitoring and regulation of water use.
Low growing season rainfall and breezes from the coast can reduce the risk of
fungal diseases. However, bacterial Pierce’s disease, spread by leafhopper insects called sharpshooters, is a serious threat. Most associated with southern California and areas of the Central Valley, it has also affected more northerly areas, such as Sonoma and Napa in recent years.3
Various weather hazards can also be a challenge for grape growing. Spring frosts can be problematic, with sprinklers and wind machines being typical methods of combatting them. Warm, dry weather means wildfires are a serious threat, which may damage vines and winery buildings in their path, but also lead to risk of smoke taint in the grapes over a much broader area.
Sustainable grape growing, winemaking and business practices are a key focus in
the state, and several sustainability programmes have been established. The California Sustainable Winegrowing Alliance provides a number of resources to aid grape growers and wineries in incorporating sustainable methods, and runs a certification programme, ‘Certified Sustainable’. A number of other certification programmes have been founded within particular counties or AVAs, for example, Napa Green Winery, Sonoma County Winegrowers, and Lodi Rules. Approximately 85 per cent of California wine production comes from wineries that are certified by one of the sustainable certification programmes across the state.4
Organic certifications are less common but growing. In the USA, to be labelled as Organic Wine, there must have been no addition of SO2 in the winemaking process. For this reason, a very small proportion of wines have this certification. By comparison, more wines are labelled with ‘certified organic grapes’, meaning that the grape growing process has been certified. (However, as in several other wine producing countries, some grape growers farm organically but do not see the value in certification.) A smaller proportion of grape growers are certified biodynamic.
What are the top varieties planted in California?
Chardonnay
Cabernet Sauvignon
Pinot Noir
zinfandel
Merlot
French Colombard
Syrah
Pinot Gris
Sauvignon blanc
Summarise the grape varieties in California?
Around two thirds of grapes grown in California are used for wine, one third are used as table grapes and raisins. The majority of grapes used for wine are black (63 per cent).
Cabernet Sauvignon and Chardonnay are by far the most planted grape varieties, each at just under 20 per cent of the state’s wine grape plantings. The vineyard area bearing grapes for Chardonnay is slightly higher than that for Cabernet Sauvignon, but greater plantings of Cabernet Sauvignon in the last few years means that this is likely to change in the next couple of years as these vines start to produce fruit suitable for wine production.
Describe Cabernet Sauvignon.
Styles of Cabernet Sauvignon vary markedly. Site can be influential; vineyards with some moderating influence generally giving fresher black fruit and some herbal flavours, less
body and lower alcohol. However, vineyard management and harvesting dates are also important, with green-harvesting and long ‘hang times’ (leaving the grapes on the vine well into ripeness and perhaps extra-ripeness) giving very concentrated, very ripe styles of wine, often with a full body and high alcohol.
All but perhaps some inexpensive wines
will be matured in oak. High percentages of
new French oak are common, but maturation
times are often shorter than they once were, and
generally the balance of fruit and oak is being
better managed now than in previous decades.
Cabernet Sauvignon, often blended with small
proportions of other Bordeaux grapes, produces
many of the most prestigious and expensive wines in California.
Describe Chardonnay.
California Chardonnay is made in a full spectrum of styles, depending on site climate, winemaking practices and price. The sites chosen for Chardonnay increasingly have been nearer the coast or with coastal influence, or at high altitudes.
A number of premium wines are made in a medium (+) to full-bodied styles, often with pronounced flavours of peach and pineapple and secondary flavours from malolactic conversion and new oak. More recently, some producers have been choosing to make fresher, leaner styles, often with less- ripe fruit characteristics (citrus fruits) and less overt new oak. Sometimes lees contact will be managed to give struck match aromas from volatile sulfur compounds.
Inexpensive Chardonnays are generally made in a soft, easy-drinking style with medium acidity, sometimes slight residual sugar and are often unoaked or made with oak alternatives.
Describe Pinot Noir.
Pinot Noir plantings have grown rapidly in the last 20–30 years. Like Chardonnay, premium and super-premium wines tend to come from relatively cool sites, whether that be due to coastal influence or altitude. Styles range from those with medium (+) acidity, medium bodyand alcohol and fresh flavours of red cherry and raspberry, to those with greater body and alcohol, medium to medium (+) acidity and riper flavours, either black fruits or slightly jammy. In general, there is a trend for earlier picking than in the past, and a proportion of whole bunch fermentation or stem inclusion to enhance aroma complexity and give greater tannic structure. Maturation in some new oak, generally French, is common.
Describe Zinfandel.
Zinfandel is often deemed as a signature variety of California, not widely grown elsewhere in the world (except in Puglia). California also has considerable plantings of old-vine Zinfandel, including some plants that are over 100 years old. Zinfandel is prone to uneven ripening which can lead to the combination of medium (+) acidity and some fresh flavours, alongside jammy characters.
Premium Californian Zinfandel often has medium (+) acidity, medium to full body, ripe medium (+) tannins and flavours that range from raspberry to blueberry and blackberry. American oak is often used for maturation, the overt vanilla flavours pairing well with Zinfandel’s juicy fruit profile. Inexpensive Zinfandel is usually made in a soft, ripe, often jammy style, possibly with oak alternatives to give some flavours of spice.
Zinfandel, usually from the Central Valley, is also commonly made into rosé wine, termed White Zinfandel. These wines are often made with a short maceration on the skins, leading
to a medium pink colour, before fermentation in stainless steel at cool temperatures. The fermentation is often stopped early to produce a medium-dry wine, often with low alcohol (around 10.5–11% abv). They tend to have medium acidity and body and flavours of strawberry and fruit candy. These wines, usually sold under some of the highest-volume brand names, are often inexpensive to mid-priced and generally of acceptable to good quality.
Describe Merlot.
Merlot was very popular in the 1990s and early 2000s, but as consumer trends changed, since that time, plantings have declined. Much Merlot is made into inexpensive and mid-priced wines with medium acidity and tannins and fruity plummy character. However, a number
of producers make premium wines from the grape, often in areas with a more moderate
rather than hot climate, such as Stag’s Leap District and Oak Knoll District in the Napa Valley. Such wines may have higher acidity and tannins, and a greater freshness and complexity of flavours. In these wines Merlot may sometimes be blended with other Bordeaux varieties.
Describe Colombard.
Colombard, called French Colombard in California, is a neutral white grape, also commonly used for IGP wines in South West France. In California, it is generally grown in the Central Valley and used in inexpensive wines. Its name is rarely seen on wine labels, and instead, wines produced from it, generally in a blend with other varieties, are labelled with a description such as ‘fruity white’ or ‘dry white’.
Describe Syrah.
Syrah has risen in popularity over recent years. It often does best in areas with some cooling influence, in which cases it can produce wines with medium to medium (+) body, medium
(+) acidity and tannins and fresh plum, blackberry and spice flavours. A small number ofproducers specialise in Rhône varieties and also produce wines from varieties such as
Grenache and Cinsaut, and whites such as Viognier, Marsanne and Roussanne.
What are some other varieties planted here?
Pinot Gris plantings have increased in the last couple of decades. Wines tend to be made in
a dry but fruity style, with peach, pear and melon flavours. Sauvignon Blanc is generally also made in a fruity style, typically fermented in stainless steel and released early from the winery. Some producers choose to ferment and mature Sauvignon Blanc in oak, giving greater body and texture, with toasty flavours. Sauvignon Blanc is occasionally labelled Fumé Blanc, but this name does not necessarily mean the wine has been fermented or matured in oak.
A large number of other grape varieties are grown in various parts of the state including those native to Italy, Germany, Spain and Portugal, as well as further French grape varieties. Petite Sirah is particularly noteworthy. This grape variety originated from France, under
the name Durif, but there is now far more planted in California (and the USA in general) than anywhere else in the world. As a late ripening variety, Petite Sirah does best in the warm areas of the state, where it produces deeply coloured, full-bodied wines with medium (+) to high levels of tannins and acidity and black fruit and spice flavours. It is also used as blending ingredient to add colour, body, tannins and acidity to other red wines.
Wine law, regulations and wine business.
California has approximately 140 AVAs. As noted previously, these vary from very large areas, such as Central Coast which extends down the coast for around 450 kilometres (280 miles), to small areas, such as Cole Ranch in Mendocino which totals just a couple of hundred hectares.
Where a single grape variety is mentioned, at least 75 per cent of the wine must be from that named variety. A wine labelled with ‘California’ must be made entirely from grapes grown in the state. At least 75 per cent of the grapes must come from any named county, for example, Sonoma County. If an AVA is mentioned, at least 85 per cent of the grapes must come from that AVA. Vineyard names may appear on the label if at least 95 per cent of the grapes are from that vineyard.
Rules for labelling wine with a vintage differ according to the geographical indication. At least 95 per cent of the grapes must come from any stated vintage if the wine is labelled with an AVA; this reduces to at least 85 per cent if purely a county or the state is mentioned.
Wineries can only use the term ‘estate bottled’ if the wine has been made and bottled at the producer’s winery, and from grapes from vineyards owned or controlled by the producer that are within the same AVA. This has led to the creation and approval of a number of very large AVAs permitting some of the state’s largest producers that may have vineyards and wineries far apart to legitimately label some of their premium wines as ‘estate bottled’.
California is the largest wine producing state in the USA. Total volume sales (both domestic and export) in 2018 were 26 million hL, of which 3.3 million hL were exported.6
California wine production is in the hands of 5,900 grape growers and over 4,800 bonded wineries. Although many wine-producing companies own vineyards, buying in fruit to supplement their own grapes is common (they may also sell some of the fruit from their own vineyards to other wineries). The bought-in grapes may come from a different AVA or even a different county, and can either be blended with other fruit (and labelled with a large AVA such as Central Coast, or simply ‘California’) or be kept separate to make its own wine (for example, a producer based in Rutherford may produce a Chardonnay entirely from Carneros fruit). Estate wineries do exist but tend to be small.This model where many wine producers are acting as either merchants or grower- merchants, means that producers can make a wide variety of wines, often beneficial in attracting consumers to taste and buy at the cellar door or join the winery’s wine club.
Independent professional grape growers that farm thousands of hectares are a key part of the structure of the business. Grape prices can vary according to supply and demand, and this has often led to the head-grafting of vineyards to keep up with the latest consumer demands. Grapes from vineyards under the management of certain well-known, quality-conscious grape growers are usually in high demand, especially from prestigious vineyards, and sell for a considerable premium. Similarly, grape prices vary dramatically according to region and grape variety, and it is one factor influencing the price of wines. Cabernet Sauvignon can usually command a premium compared to other grape varieties. Napa Valley fruit can be around ten times the price of fruit from Lodi.
Wine producers range in size from those producing a few hundred cases to some of the largest wine companies in the world. E & J Gallo was founded in Modesto, California in 1933 and is now the largest wine company in the world, selling around 70 million cases (6.3 million hL) throughout the world in 2018.7 It also owns the world’s largest selling brand, Barefoot Cellars. In contrast, there are also a number of wineries producing very small volumes of outstanding quality wines (often termed ‘cult’ wines) which are in incredibly high demand amongst collectors and some investors, and are among the most expensive and hard-to- obtain wines in the world. Examples include the wines from Screaming Eagle Winery and Harlan Estate.
The Wine Institute of California represents the California wine industry and has about one-fourth of the producers as members. Many counties and AVAs also have their own trade associations.
Summarise The North Coast AVA.
The North Coast AVA is a large AVA in California, running about 160 kilometres (100
miles) down the Pacific Ocean coastline and reaching 80 kilometres (50 miles) inland. It encompasses substantial proportions of Napa County, Sonoma County, Mendocino County and Lake County. The Mayacamas Mountains run through the North Coast AVA, dividing Mendocino and Lake County, and extending south for over 80 kilometres (50 miles) into Napa and Sonoma, down to San Pablo Bay.
Summarise Mendocino County.
Mendocino County runs along the Pacific Ocean to the west, with Lake County to its east, and Sonoma County to its south. Of around 1 million ha, almost 7,000 ha are under vine.9 Vineyards are grouped either in the cooler AVAs closer to the Pacific Ocean or further inland in warmer areas, some of which are planted at altitude. The more coastal AVAs (such as Anderson Valley) tend to specialize in Pinot Noir, Chardonnay and aromatic white varieties. Inland AVAs (such
as Redwood Valley) are able to ripen Zinfandel, Syrah, Petite Sirah and Cabernet Sauvignon, though those with vineyards at particularly high altitudes (such as Potter Valley) can produce aromatic whites such as Sauvignon Blanc and Riesling. Mendocino grapes are generally priced lower than those grown in Napa and Sonoma and are often used for multi-regional blends.
The county encompasses 13 AVAs.10 The Mendocino AVA which starts at the Russian River headwaters, covers six of the county’s AVAs (Anderson Valley, Yorkville Highlands, McDowellValley, Potter Valley, Redwood Valley and Cole Ranch), and can be used for multi-regional
blends between these AVAs.
Summarise Anderson Valley AVA.
Anderson Valley is the most well-known of Mendocino’s AVAs. The valley runs from north-west, only a few kilometres/miles from the Pacific, to south-east, which is further inland. Day-time temperatures can be warm but cold air and fog are funnelled inland along the Navarro River, giving cold evenings and mornings. Further inland, the valley becomes narrower and reduces the flow of ocean breezes and fog and conditions are warmer.
The valley receives plentiful precipitation ranging from 900–2,000 mm per annum, mostly falling in the winter and spring, with the north-western side of the valley being the wettest. The vast majority of the vineyards are planted on the sloped sides of the valley. Cold nights mean frost can be an issue in the spring particularly in low-lying areas.
Just over 1,000 ha are planted.11 Early-ripening Pinot Noir and Chardonnay are the two most planted varieties, and are used in both sparkling and still wines. In terms of still wines, Pinot Noir has become particularly reputed. Style varies depending on site climate, clones used and harvesting times, but the wines generally have fresh raspberry, cherry and plum fruit, medium body and medium (+) acidity. They are generally good to outstanding, and premium priced, with some super-premium examples. Significant producers include Littorai and Williams Selyem. Aromatic Alsace-style white wines from Gewurztraminer, Riesling, Pinot Gris and Pinot Blanc are also successfully produced.
There are approximately 85 wineries in the AVA, many of which have cellar doors to take advantage of the tourist trade around the Mendocino coast. The reputation of the AVA for Pinot Noir means a number of wineries from other areas of the state buy Anderson Valley fruit to make appellation-specific (or even vineyard-specific) wines.
Summarise Lake County.
Lake County is in the rain shadow of the Mayacamas Mountains to the west and the Vaca Range to the east, giving a warm climate. Most of the vineyards are in the southern part of the county around Clear Lake, the state’s largest natural lake.
Lake County has 7 AVAs.12 Clear Lake AVA is the largest and has four sub-AVAs. The lake, which takes up around half of the area of the AVA, provides afternoon breezes. Furthermore, many of the vineyards are planted on the slopes and ridges around the lake and, at 400–450 m, benefit from the cooling effects of altitude. Black grape varieties make up the majority
of plantings and Cabernet Sauvignon and Sauvignon Blanc are the two most planted grape varieties. Just over 200 ha are planted.
There are a small number of prestigious vineyard sites and wineries in the county. However, much of the inexpensive Lake County grapes are used for multi-regional blends.
Summarise North Coast - Sonoma County.
Sonoma County borders the Pacific Ocean and Mendocino, Lake, Napa, and Marin counties, and encompasses 18 AVAs.13 There are three overarching AVAs – Northern Sonoma AVA, Sonoma Coast AVA, and Sonoma Valley AVA – so large that they overlap with each other and encompass various smaller AVAs with specific climates and geographical features. As mentioned in Wine Laws and Wine Business, these overarching AVAs allow producers touse the term ‘estate bottled’ when their vineyards and winery are spread far apart, whilst still permitting the word ‘Sonoma’ to appear on the label (rather than North Coast).
If a wine comes from an AVA that sits entirely within Sonoma County, the words ‘Sonoma County’ must appear on the wine label (along with the name of the AVA).
Summarise Northern Sonoma AVA.
The Northern Sonoma AVA covers a large area, from the Mendocino border to the north, the Mayacamas mountains to the east, down to Santa Rosa, situated in the middle of Sonoma County. Its vineyards are separated from the Pacific Ocean by the Sonoma Coast AVA. It
is further defined by the Russian River, which starts north in Mendocino County and flows through the Northern Sonoma AVA where it fills underground aquifers and provides water for vineyards, before flowing into the Pacific Ocean. It incorporates several smaller AVAs including Alexander Valley, Knights Valley, Rockpile, Chalk Hill, Russian River Valley (plus Green Valley of Russian River Valley) and Dry Creek Valley.
Summarise Alexander Valley AVA.
The Alexander Valley AVA is in the northeast corner of Sonoma County. It has a warm climate, which is cooled in the evenings by Pacific air funnelled in from the Petaluma Gap and Russian River Valley to the south. Vineyards are planted both on the valley floor and on west / southwest facing slopes and benchlands of the Mayacamas mountains, at elevations of 100 to 750 m. The aspect and altitude of these vineyards give long hours of bright sunshine, leading to grapes that are high in colour and tannins. The influence of altitude also helps to retain acidity in the grapes. There is a mixture of soils with greater fertility on the valley floor and more low-nutrient, free-draining sand and gravel at higher altitudes, generally leading to less vigour and lower yields. Average rainfall is just over 800 mm per year, but mainly falls in the winter.
Cabernet Sauvignon is the most planted variety and produces full-bodied wines with
ripe flavours of blackberry, blackcurrant, dried herbs and chocolate. Those from plantings
on the valley floor tend to have less tannin, whereas those from grapes on the slopes and benchlands tend to be more structured and concentrated. Alexander Valley Cabernet Sauvignons are typically good to outstanding in quality and mid-priced to premium in price, with some super-premium examples. There are also notable plantings of Chardonnay, Merlot, Zinfandel, Petit Verdot and Malbec. Significant producers, among many, include Kendall- Jackson (including the Stonestreet Estate) and Seghesio.
Summarise Knights Valley AVA.
The furthest-inland AVA, and separated from the northern end of Napa County by the Mayacamas mountains, the Knights Valley AVA is one of the warmest areas of Sonoma County. It is surrounded by hills and sheltered from any cooling influence of the Pacific Ocean.
However, cooler sites can be found by planting at higher altitudes (around 450 m) in the foothills of the Mayacamas. The warm temperatures and warm, free-draining volcanic soils help to produce ripe, full-bodied Cabernet Sauvignon, the most planted grape variety in the AVA. Merlot, Syrah, Zinfandel and some Chardonnay and Sauvignon Blanc are also grown.
Summarise Dry Creek Valley AVA.
Best known for Zinfandel and Sauvignon Blanc, the Dry Creek Valley AVA is a narrow valley 3 by 26 kilometres (2 by 16 miles) with vineyards planted on both the valley floor and on slopes and benchlands either side of the Dry Creek river, a tributary of the Russian River. Sheltered by coastal mountains to the west, Dry Creek Valley has warm days. However, mountains on either side of the valley funnel cool ocean air and fogs from San Pablo Bay (a tidal estuary, the northern extension of San Francisco Bay). This occurs during the afternoon and evenings, giving much cooler nights and helping to retain acidity in the grapes. There are slight differences in climate throughout the valley. The coastal influence means the south of the valley is generally cooler. West-facing vineyards on the east of the river which are exposed to the warm afternoon sun tend to be warmer than those on the western slopes.
Soils are mixed but tend to be gravel sandy loam on the valley floor and gravel red clay loam on the slopes and benches. These gravelly free-draining soils help to reduce vigour and yields.
The AVA is particularly known for its Zinfandel and is home to some old vines of over 100 years old. The wines tend to be medium (+) to full-bodied, with medium (+) acidity and ripe flavours of blackberry, black plum and cherry. Those from the west-facing sites and vineyards in the north of the appellation are often riper, with more jammy and dried fruit flavours than the fresher styles from the east- facing vineyards and those within the south of the appellation. Maturation in oak is typical, usually with a proportion of new oak to lend notes of spice; American oak is common. The wines range from good to outstanding and mid-priced to
premium. Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot and Rhône varieties (Syrah, Grenache, Mourvèdre, Cinsault, Carignan) are also produced. The key white variety is Sauvignon Blanc. Significant producers include Kinsella Estates and Ridge.
