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A Technical Guide for Wine Producers
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The South African Wine Industry: variety is in our nature
Dr Victoria Carey, Department of Viticulture and Oenology, University of Stellenbosch
The nature
The South African wine industry is concentrated in the south western and southern parts of the tip of Africa, which is flanked by ocean on three sides. The western coast is bathed by the cold Benguela current while to the south, the warmer Agulhas current is present. The cold water on the western coast contributes to lower rainfall and eventually the desert conditions of the Namib desert, while along the south and eastern coasts the summer drought of the Mediterranean climate becomes less until it eventually reaches sub-tropical conditions in Mozambique. This strong ocean influence results in summers in the South African wine lands being cooler than similar latitudes in the northern hemisphere. The broken relief resulting from the narrow coastal plain, the fold mountains that follow the coast line and the deep narrow valleys result in very varied rainfall. Temperatures also range from moderately cool near the coast and at higher altitudes to very hot in the inland river valleys.
Soil formation occurred from this parent material during a time when the land went through cycles of being covered by the ocean and subsequently exposed. This together with the complex topography resulted in diverse soils being found within close proximity. Some of the most important soils for viticulture, the deep red or yellow brown structureless soils that are associated with granitic hills or slopes of the mountains, were formed in a period when southern Africa was under a tropical climate. These soils are highly weathered and acid, and are well-drained yet have a good soil water holding capacity. Found in lower positions in the landscape, on the footslopes of the hills and mountains, are the duplex soils. These soils have a layer of sand over a more clayey layer. On the crests of the undulating hills, one can find residual soils, weathered rock of either granite or shale origin. In the valleys, alluvium of varying nature is present.
An interesting feature of many of the hill or mountain slopes is the "measled" appearance: dark green circles of vegetation amongst the more usual lighter green. These darker circles are due to soil differences, related to ancient termite activity. This activity resulted in soils with a better structure, more optimal pH, better soil water holding capacity and a higher base status. This translates into more vigorous and bigger grapevines in these areas.
The diverse natural environment is reflected in the diversity of the natural vegetation. The wine lands are associated with the renowned Cape Floral kingdom. This kingdom is home to proteas, ericas, daisies, irises, grasses, reeds, pelargoniums and many other plant types. In fact, it contains more than 8 700 plant species, making it the richest plant kingdom, despite being the smallest in surface. Many of these species are very site specific and are only found within a single square kilometer. Because this rich diversity of plant life is a heritage of the diverse climates and soils in the wine growing area, we can expect that these same climates and soils will provide many diverse wine styles.
The beginning
The first person to plant grapevines in South Africa was sent by the Dutch in 1652 to establish a halfway station on the tip of Africa. His name was Jan van Riebeeck. This halfway station was expected to provision the ships of the Dutch East India Company as they rounded the Cape on their journey along the spice route. Being a former ships surgeon, Jan van Riebeeck believed that wine was an important provision to prevent scurvy during long voyages and so he imported grapevines from Europe and planted them in the gardens of the fort in 1655. On 2 February 1659 he is reputed to have written in his diary "Today, praise be to God, wine was pressed from Cape grapes for the first time . . .".
The French Huguenots that were encouraged to immigrate to the Cape Colony also helped to stimulate the industry because of their greater knowledge of wine growing practices. They mainly settled in the areas of Franschoek (literally meaning French corner), Stellenbosch and Paarl.
The 18th and 19th centuries held many opportunities, but also challenges for the small South African Wine Industry. The quality of South African wines, with the notable exception of Constantia wines, was not of the highest standard and there was of course resistance on both sides of the export market (Europe and the East). Transport of the wine was a problem due to the distance of South Africa from the market. The wine was not bottled before export but transported in oak vats. As South African oak could not be used to manufacture these vats due to the high porosity of the wood, the vats had to be brought from Europe, often resulting in shortages at the Cape. The vats that were used for wine storage had therefore often been used for other purposes, including brining of meat, and thus did little to enhance the quality of the wines. There was also no protection of geographic indication and unscrupulous merchants used well known names, like Constantia, fraudulently. After the first British occupation of the Cape in the early 19th century, and the subsequent war between France and England, the market for South African wines in the United Kingdom expanded and the young industry grew rapidly. However, peace between Britain and France was resolved and the South African exports collapsed. This was shortly followed by the advent of the phylloxera plague. These factors, together with civil war, wreaked havoc with the wine industry. None the less, mass replanting ensued; resulting in surplus production and exceptionally low prices.
In order to stabilize the industry, cooperative ecllars were established, culminating in the establishment of the KWV (Ko-operatiewe Wijnbouers Vereeniging van Zuid Afrika). It had the power to fix quotas and minimum prices and it removed surpluses through distillation and sales on overseas markets. Although this organization ensured that farm incomes were sustained it had the outcome that innovation was limited.
The wine industry today
Together with many changes on the political scene (release of Nelson Mandela in 1990 and the first democratic elections in 1994) and thus a change in the export opportunities for South African wines, regulation of the industry ceased and quotas were abolished. This led to a period of growth and innovation in the South African wine industry. New regions with the potential to produce high quality wines have been identified and planted to grapevines. New industry players with a strong spirit of entrepreneurship and ideas for renewal and innovation have emerged. Wine cooperatives are increasingly being converted to companies, and establishing their own marketing and export campaigns. This led to the industry leaders recognizing that a vision for the future of the wine industry was needed and Vision 2020 was initiated to propose detailed strategies for the wine industry with the overall aim being "A South African Wine Industry that is innovation driven, market directed, globally competitive and highly profitable, while retaining strong cultural roots, instituting ethical trade practices and meaningful social responsibility programs, and implementing strategies for affirmative action". This identified a need for a unifying organization, which was initially named the South African Wine and Brandy Company (SAWB) and has recently been renamed the South African Wine Council. This organization has a board of directors that represents all stakeholders in the wine industry. There are four business units that are responsible for the roll out of the strategies identified in Vision 2020 and formalized in the Wine Industry Strategic Plan by SAWB, namely a unit for human resource and economic development and empowerment, a unit for generic market development and promotion, a unit for knowledge and information services and inspections and finally a unit for technology innovation and transfer. The Wine Industry Plan is in place to deal with the legacy of a highly regulated economic environment and challenges such as increasing global competitiveness and historical discrimination along racial and gender lines.
The extent of the South African Wine Industry
The South African wine industry represents three categories of products, namely wine (70%), rebate and distilling wine (23%) and non-alcoholic products (7%), and in 2005 accounted for a total production of 8 657 220 hL. This production was from a total of 101 607 ha of wine grapes with the cultivar spectrum shown in Figure 1.
This cultivar spectrum has changed over the past 10 years with a current focus on premium cultivars. Unplanned, haphazard plantings are a thing of the past with new plantings being based on an inventory of soil types. Based on the soil maps, vineyards are demarcated to ensure homogeneity. Best adapted rootstocks are selected and correct soil preparation techniques are applied. Vine spacing and trellising systems are chosen based on expected vigour. These decisions are aimed at creating vineyards with moderate and homogenous vigour. There is also an increasing focus on the creation of environmentally friendly vineyards under the direction of Integrated Production of Wine (http://www.ipw.co.za).
Soils are subjected to deep delve ploughing with adapted implements and lime, phosphor and potassium are ameliorated before planting. Lime is necessary because many of the soils in the South Western Cape have acidic sub-soils. The main rootstocks used are Richter 99, Richter 110 and 101-14 Mgt. On average 3 435 vines are planted per hectare, dependant on the specific site and cultivar x rootstock characteristics. Most grapevines are vertically shoot positioned, cordon-trained and spur pruned with approximately 16 buds per meter cordon. During summer months, suckering is performed, shoots are positioned and trimmed. Crop control is performed on weak shoots. Many vineyards in South Africa are irrigated. In some instances, where rainfall is usually sufficient, this irrigation is only applied during dry seasons. In other instances, for example in Robertson where the annual rainfall is less than 300 mm, full irrigation is applied - often in the form of regulated deficit irrigation. Irrigation is generally applied by means of drip or microspray systems. Limited nitrogen fertilization is applied, and only in situations where leaf and soil analyses and the grapevine vigour indicate that it may be necessary. As clean cultivation is generally practiced, grain is planted in between vineyard rows in the winter and left as a mulch during the summer. The use of permanent cover crops in high vigour situations is however increasing.
The main diseases that have to be dealt with in the vineyards are downy mildew, powdery mildew, boytytis, eutypa lata and leaf roll. Research into the most suitable methods for prevention and treatment of these diseases is current. For downy mildew a disease warning system is in place, which allows for use of systemic agents post-infection. For powdery mildew care, is taken to ensure that disease resistance to Sterol Biosynthesis Inhibitors is prevented. As far as pests are concerned, phylloxera is present in almost all vineyards and grapevines are thus grafted. Planococcus ficus, is considered to be one of the most important pests as it has been identified as a vector for leaf roll transferal between vines and is thus an agent for reinfection of clean plant material with the closterovirus complex. Ants protect Planococcus ficus from its natural enemies (e.g. lady bugs) and thus also need to be controlled. Much research is directed towards the prevention of the spread of leaf roll in vineyards and particularly through control of Planococcus ficus and ants.
Terroirs for South African wines
Initially vineyards were situated close to trading posts and within full view of bays to view approaching ships. The two best examples of these are Constantia, the farm of Simon van der Stel, which is on the slopes of the Constantiaberg, facing towards False Bay, while Vergelegen, the farm of Willem van der Stel (the son of Simon) is situated on the other side of the False Bay. There is in fact a position on this farm from where it is also possible to see across the Cape Flats to Table Bay. The easy access of Willem van der Stel brought him into conflict with the free farmers of the Cape Colony and he was eventually sent back to Holland as a result of their complaints.
Viticulture did not stay near the coast. As the farmers moved further inland so vineyards were established in valley floor positions, close to available water as irrigation was necessary in these low rainfall areas. More recently research into improved soil and water management technologies has led to vineyard development on slopes. These areas generally have warmer climates and have been responsible for the production of the majority of fortified wines and rebate wine for brandy production. They currently produce table wines of high quality as a result of improved viticultural and oenological practices.
Since the lifting of the quota system, new zones have been developed at high altitudes and along the coast. These areas have cooler conditions for viticulture and are becoming renowned for their aroma-full white wines.
The wine of origin system
The Wine of Origin scheme was initially legislated in 1973 with the objectives to serve as a basis for the development of distinctiveness and quality of wines; to confirm the correctness of certain indications in connection with the origin of wine and to create confidence in these indications. The importance of origin was seen as residing in the characteristics of soil and climate. Boundaries of areas of origin were therefore compiled based on these characteristics and defined by law. In order to define the boundaries the demarcation committee, consisting of experts in soil science, viticulture and oenology, investigates all available information and recommends the boundaries to the board after consultation with the producers of the area in question. Because of the considered importance of origin, in order for a wine to be certified as a wine of origin, 100% of the grapes must be grown in the demarcated area and it must be made and bottled in this same area. Legislation regarding vintage and cultivar are less strict and only 75% of the wine must be from the stated vintage or cultivar (85% in the case of exports to the EU). A wine will only be certified by the Wine and Spirit Board if all the requirements of the scheme with respect to origin, cultivar and vintage have been met and the wine has been sensorially evaluated by one of the tasting panels of the Board and no unacceptable quality characteristics were found.
The areas of origin are described in a pyramid system (Figure 2). A geographical area is defined by the macrogeographical characteristics related to provincial boundaries (e.g. winter rainfall region of Western Cape). This is the largest area that can be defined. The region is the next largest. It is mainly described by an encompassing area name (e.g. coastal, or the name of a river). A district is defined according to patterns of soil occurrence and macroclimate and must be described by a real geographical place name. Macrogeographical characteristics such as mountains or rivers are often used as boundaries. The most refined delimited area is that of a ward. Here soil, climate and ecological factors are taken into account. The proposed area name has to be a real geographical place name and nature has to dictate that the specific area has the potential to produce wine with distinctive characteristics. Often the areas that are delimited have only recently been planted to vineyards or are at present characterized by few vineyards but have the potential for development. It is a dynamic system with increasingly stringent criteria for demarcation.
Terroir studies in South Africa
Environment has long been recognized as being an important contributor to wine character and quality and in order to assist the demarcation of areas of origin, studies into the effect of environment on viticultural and oenological performance were initiated. The first studies in the early 1970’s were focused on the mapping of climate and climatic indices. Simultaneously, investigations into the effect of soil on Cinsaut and Chenin blanc under the same macroclimate were performed. Viticulture was not the only focus and in order to assist all agriculture, a nationwide survey of natural resources and the mapping of land types commenced in 1971. A land type is "a class of land over which the macroclimate, the terrain form and the soil pattern each displays a marked degree of uniformity" and will differ from another unit in terms of at least one of the following parameters: terrain morphological types, pedosystem, macroclimate or geology. 1:250 000 maps and memoirs for the whole country were completed in the early 21st century. The memoirs contain inter alia descriptions of terrain morphological units and an inventory of the main soil forms to be found on each of these units as well as the principal soil depth and texture per soil type. These land types are often used as a basis for the delimitation of wards of origin.
Although these studies focused on the environment, the first studies under the name of terroir started in 1995. The definition upon which these studies are based describes a viticultural terroir "as a unit of the earth’s biosphere that is characterised by relatively homogenous topographical, pedological and climatic features, which find expression through interaction with the vine and vintner, resulting in a distinct wine with an identifiable origin". Terroir studies are grouped under an industry wide research program with the overarching aim being to integrate all data pertaining to the interaction of different cultivars with their growing environment in a data base and GIS platform in order to be able to formulate a model to serve as a decision aid for site selection. The more general aims of the program are as follows:
To better understand the terroir/vine/wine interaction for optimal choice of cultivar, vineyard and cellar technology, in order to:
In order to meet these aims, terroir zoning studies have taken place on three levels. At the macroscale, a study was initiated to identify potential winegrowing areas and to characterize present and potential wine growing areas in terms of their viticultural potential (both yield and wine character) based on environmental attributes. The result was a map of viticultural potential of the Western Cape. This is often used by vitiuclturists as a first approximation of an area’s characteristics and associated viticultural potential. Research is mostly focused at a mesoscale. Preliminary studies into the delimitation of terroir units at the level of a district have been performed for Stellenbosch wine of origin district. Natural terroir units were delimited based on terrain morphological unit, height above sea level, slope aspect, soil type and geological origin. The degree of influence by the sea breeze was also taken into account. At the same time a network of experimental plots was monitored for a period of 7 years and a survey was performed amongst wine growers in order to determine the response of the grapevine to environmental variables. These data were used to construct decision trees that were applied to the mapped environmental data to delimit terroirs with specific viticultural and oenological potential. Microscale studies are generally limited to farm-level consulting services. Geographic Information Systems are used to integrate scientific knowledge, environmental data and mathematical modeling to create maps of relevance for viticulture (e.g. slope, aspect, relief, openness of the landscape, rainfall, soil physical properties, etc). The resulting maps are used for planning decisions for vineyards in order to ensure the best vineyard placement and block design to minimize variability within management units; to choose the optimal row direction, planting density, row width and trellis system; to choose the best cultivar rootstock combination; as a guideline for irrigation designs to ensure water supply to all vines and as a guide to assist in the determination of soil preparation techniques, amelioration requirements and erosion control strategies. These maps are also useful to assist management decisions, such as identifying reasons for heterogeneity in blocks, determining optimal block combinations to obtain the desired wine character and to make long term strategic planning decisions based on the land potential.
Adding value to the concept of terroir
Although research into terroir identification and characterization was initially driven by research and industry leaders, it appears to now have the general support of the South African wine industry and interest in the concept is growing rapidly. In 2006 two publications were released that reflect this growing interest. The first is a book by Elmari Swart and Izak Smit called "The essential guide to South African Wines: Terroir and travel", which presents the existing wine-producing regions in a system that they call "Wine Pockets". Each Pocket highlights a specific terroir, giving an overview of the characteristics of each wine-producing area, and associates it with wine styles. The second publication is a set of maps of delimited Wine of Origin Districts and Wards published by Wines of South Africa. On the reverse of each map is a table that provides the reader with all the pertinent topographic, climatic, soil and geological information so that the reader can better understand the dominant influences on viticulture in the described area.
Together with the inception of the Wine of origin scheme, wine routes were established in the different wine growing regions. These wine routes are well organized with maps and signboards directing the visitors to cellars that are open to the public for tasting. The characteristic Cape Dutch farm homesteads, with their gabled facades and thatched roofs are often opened as museums or restaurants. These initiatives are expanding and obtaining greater significance in the different wine producing areas.
Finally, the generic marketing campaign by the organization Wines of South Africa for brand South Africa is based on the slogan "Variety is in our nature". This is focused on the rich biodiversity of South Africa, and in particular the fynbos associated with the Western Cape wine producing areas and its relationship to the diverse terroirs that are available for wine production in South Africa, which give rise to unique and individual wines.
Summary
The geographic position, ancient geological history and complex topography of the South Western Cape have resulted in varied climate and soils. The diverse natural environment is reflected in the diversity of the natural vegetation which forms the basis for the generic marketing campaign by the organization "Wines of South Africa". The origin of wine is protected by the Wine of Origin scheme and the factors contributing to their distinctiveness are studied in the Winetech terroir research program.
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