Orientador: Luís Henrique Bassoi / Resumo: Sensores podem auxiliar no monitoramento do nitrogênio no tecido foliar e da água no solo, mas para esse propósito eles necessitam ser calibrados. Assim, o presente trabalho teve como objetivo propor um procedimento para o uso do clorofilômetro em ma área de produção comercial de uva para vinho, no contexto da vitivinicultura de precisão, avaliando a variabilidade temporal do teor de nitrogênio foliar e as suas relações com as zonas homogêneas de solo e da planta. O estudo foi desenvolvido no município de Espirito Santo do Pinhal, estado de São Paulo, no ciclo de produção de 2019 de um vinhedo com a cv. Chardonnay sobre o porta-enxerto Paulsen 1103. O vinhedo foi irrigado e fertirrigado por um sistema de irrigação por gotejamento. O equipamento HS2 HydroSense, calibrado para diferentes zonas homogêneas quanto a fração granulométrica do solo, foi utilizado em 6 datas durante o ciclo de produção para a determinação do conteúdo de água a 0-20 cm de profundidade, e em 20 pontos por zona. O índice relativo de clorofila foi medido pelo clorofilômetro ClorofiLOG CFL 1030 em 4 datas durante o ciclo de produção, e em 40 plantas por data. Para a calibração do clorofilômetro, amostras de folhas foram coletadas para a determinação em laboratório dos teores de clorofila e de nitrogênio. A produção por planta, número de cachos por planta, massa média de cachos por planta e produtividade da área total foram determinados. A maturação tecnológica das bagas foi observada por amostragens periód... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sensors can assist in monitoring leaf tissue nitrogen and soil water, but for this purpose they need to be calibrated. Thus, the present study aimed to propose a procedure for the use of a chlorophyll meter in a commercial growing area of wine grapes, within the context of precision viticulture, evaluating the temporal variability of leaf nitrogen content and its relationship with homogeneous soil and plant zones. The study was carried out at Espirito Santo do Pinhal, state of São Paulo, Brazil, in the 2019 growing season of vineyard of cv. Chardonnay grifted on Paulsen 1103 rootstock. Plants were irrigated and fertigated by a drip irrigation system. The HS2 HydroSense equipment, calibrated for different homogeneous zone of soil fractions, was used to determine the water content at 0-20 cm depth in 6 days throughout the growing season, at 20 points in each zone. The relative chlorophyll index was measured using the chlorophyll meter ClorofiLOG CFL 1030 in 4 days throughout the growing season, in 40 plants by day. Leaf samples were collected for laboratory determination of chlorophyll and nitrogen contentes and calibration of the chlorophyll meter. The production per plant, number of bunches per plant, average mass of bunches per plant and yield (total area) were determined. The technological maturation was observed by periodic sampling of berries to determination of pH, malic acid and soluble solids in laboratory. From the mathematical models generated, the chlorophyll meter ... (Complete abstract click electronic access below) / Mestre

This research is a case study on the wine producing region of Beaujolais, France. It investigates the potential that organic wine tourism, which promotes the benefits of responsible wine production methods, has to positively rebrand Beaujolais. Indeed, the region has suffered from a bad reputation for the past decades, even though an increasing number of small to medium domains have started producing organic wine. Mixed methods have been used to investigate the extent to which the demand of potential tourists meets the supply of organic wine tourism activities that the previously mentioned domains are able/willing to provide. A questionnaire analysis has revealed that a diverse range of people living in the nearby area are curious about organic wine tourism and would therefore enjoy tasting organic wines at small domains, even though they do not know much about the topic. However, interviews with owners/managers of small organic wine domains have revealed that they currently face too many obstacles to properly answer the demand for organic wine tourism. Furthermore, they identify wine industry professionals as their prefered visitor target, rather than regular tourists such as the ones having answered the questionnaire. As a result, the supply of alternative wine tourism initiatives by small organic domains does not currently live up to the expectations of the customer segment wishing to experience organic wine tourism.

Cluster thinning, leaf removal and kaolin application are three commonly employed means of modifying fruit zone microclimates assumed to improve grape and wine quality. High labour costs in addition to the potential for location and varietal-specific responses make the benefits of these practices equivocal. To explore this question, I employed a stratified random block design in two Vancouver Island commercial vineyards where Pinot gris vines were manipulated with one of four experimental treatments: control, cluster thinning to one cluster per shoot, heavy leaf removal with a Kaolin clay application, or a combined heavy leaf removal – cluster thinning - Kaolin treatment. The resulting wines were subjected to detailed sensory evaluations, consumer valuation, and a cost-benefit analysis to determine their respective return-on-investment. Results indicate that despite apparent sensory changes driven by vineyard treatments, the lack of any perceived added value suggests that regional producers of Pinot gris should avoid using the assessed treatments as strategies to increase wine quality. The cost-benefit analysis revealed that heavy leaf removal combined with Kaolin clay application may provide a benefit outside of changes to wine quality. The demonstrable improvement in growing conditions under this treatment resulted in a significant decrease in rot pressure. This suggests that the treatment may be a viable option for increasing usable yields of Pinot gris without placing an insurmountable financial cost on the producer. / Graduate

A two-year study was conducted at a commercial vineyard in California’s Templeton Gap AVA to evaluate the effect of vine age on viticultural, enological, and sensory attributes of Vitis vinifera L. cv. Zinfandel grapes and wines. The experimental block was dry farmed, conventionally managed, with own-rooted Zinfandel vines that, when determined unproductive, were replaced with new vines of genetically identical scion plant material grafted onto St. George (Vitis rupestris Scheele) rootstock. Treatments included Young vines (5 to 12 years old), Control (representative proportion of young to old vines in the block), and Old vines (40 to 60 years old). Results indicated Young vines progressed more slowly during berry formation and more rapidly during berry ripening than Old vines. Due to variation in the timing of sugar accumulation, Old vines were harvested 21 days after Young vines in 2019, and 9 days after in 2020. Old vines produced, on average between both seasons, 3.7 kg more fruit per vine than Young vines. Old vines also produced, on average between both seasons, 22.8 more clusters per vine than Young vines (5.41 tons/acre and 2.64 tons/acre, respectively). The larger vine capacity observed was attributed to Old vines having more arm, spur and dormant bud positions per vine than Young vines, in addition to larger trunk circumference and diameter. Vine age also had an effect on vine vegetative growth, with Old vines producing shorter internodes (25.5% decrease) and smaller shoot diameters (29.3% decrease) compared to Young vines. Young vines had higher mid-day stomatal conductance and tended to have higher mid-day photosynthetic rates, although no differences in corresponding pre-dawn measurements were found. While root architecture was similar between age groups, Old vines displayed greater rooting depths. Young vine wines had lower pH and titratable acidity than Old vine wines. Old vine wines were defined by a wider array and intensity of aromatics, including raisin, orange peel, black fruit and spices relative to Young vine wines which were defined by wet topsoil and pomegranate aromas. These results suggest the potential for greater yield and improved wine quality when extending the longevity of Zinfandel vineyards.

Descriptive sensory analysis is essential to understanding how differing varietals, viticultural techniques, enological techniques, vintage, regions, etc. impact the sensory characteristics found in wines. These studies analyzed the sensory impacts of vine age, whole cluster and stem addition influences, the frequency of cap management regimes, and selected fermentation variables, on 2019 Zinfandel, 2020 Syrah, 2020 Tannat, 2020 Cabernet Sauvignon, and 2021 Graciano wines respectively, from the Central Coast of California, USA. The investigation of Old vine Zinfandel indicated that these wines were defined as complex due to the wide variety of descriptors used to characterize them, having high color saturation and long length, while the Young vine wines were described as considerably less aromatically diverse, yet being defined by high intensity wet topsoil and pomegranate aromas. Acknowledging the absence of literature on classifying Californian Tannat, descriptors such as high color saturation, purple hue, cooked blue fruit, violet, raisin, bitterness, and astringency may serve as descriptors to these uncommon wines. Regarding stem addition, Dried stem wines exhibited the highest color saturation, purple hue, and astringency intensities in both the Syrah and Tannat wines. Generally, the Green stem wines were less lifted, however the presence of stems added a sense of freshness. The Whole cluster and Control wines generally opposed each other. With reference to cap management, as punch down (PD) increased, perceptions of the overall astringency, bitterness, and velvety characteristics increased. Concerning the various fermentation variables, dirty (unwashed grapes prior to fermentation) wines were described by the earthy aroma, washed (washed grapes prior to fermentation) wines by the floral aroma, and spontaneous (uninoculated) wines by the fruity aromas; however, fruity was the predominant aroma across most wines.

A two-year study was conducted to assess the effects of cofermentation on red wine varietals. During the winemaking process, wines can be made from two or more varieties by picking, crushing and fermenting them together, a practice known as cofermentation. They can also be blended either after the completion of alcoholic fermentation or after malolactic fermentation. In the first year of the study, two grape varieties, Merlot (Mer), and Malbec (Mal) were cofermented. On the second year, a third varietal, Petite Sirah (PS) was also studied. Cofermented wines containing every possible binomial combination of the varietals was made and one trinomial on 2019. The cofermented wines were compared to monovarietal wines and also to wines that were produced by blending either after alcoholic fermentation or after malolactic fermentation. The phenolic profile of the wines was followed from the onset of fermentation up to 36 months of bottle aging for the 2018 vintage and in the case of the 2019 vintage, up until 250 days after crushing. In 2018, cofermented wines and wines that were blended after malolactic fermentation had an anthocyanin profile that was more similar to Malbec than to Merlot, while the tannin profile was more resemblant of Merlot. In 2019 cofermentation improved the anthocyanin content when compared to post alcoholic and post malolactic blend only when the three varietals were cofermented. A sensory analysis with 10 trained individuals was conducted on the 2018 vintage. It was demonstrated that Malbec wines had a higher amount of red fruit aromas while Merlot wines were perceived as being more astringent. Cofermented and post malolactic fermentation blended wines were indistinguishable to panelists and blending after alcoholic fermentation produced wines that highlighted the individual varietal character.

Invasive species are a growing issue that will compound under climate change. Rising temperatures, fluctuating precipitation and new transportation pathways will create new opportunities for invasive establishment. A direct and impactful consequence of climate change is the removal of climatic barriers to invasive survival. Species distribution modeling (SDM) for invasives must include an evaluation of future establishment potential so that managers can prioritize regions forecasted as high risk under climate change. Climatic SDMs effectively support pan-invasion risk assessments by forecasting potential invaded areas globally where climatic barriers have shifted the potential for establishment. Rarely is regional-scale climate variation considered in invasive SDMs, despite its relevance for pests that establish outside their native regional climate. Here, I apply a climatic pest risk framework to the Spotted Lanternfly grape pest (Lycorma delicatula, SLF). I assess how climate change shifts the establishment potential of SLF across important viticultural regions worldwide. I contrast an ensemble of three regional-scale SDMs to a global-scale SDM, which provided multiple predictions on how future regional climate variation might shift national SLF risk levels, impacting the global wine market. I found that the global suitable area for SLF will increase under climate change, with range expansion outpacing contractions by about 1.1 million km2. Expansions will primarily occur at present northern range edges in Europe, North America, and East Asia, and contractions will occur across the southern hemisphere. Next, 307 global viticultural regions (29% of 1,063 total sampled) will decrease in risk for SLF establishment and only 532 (50% of 1,063) will remain at any risk under climate change. Loss in SLF establishment risk under climate change followed a latitudinal gradient in the northern hemisphere. Meanwhile, only 85 known SLF populations (11% of 769 rarefied sample) will destabilize under climate change. Populations within the US and South Korean invaded ranges will remain stable with respect to climate. Our regional-scale ensemble emphasized the importance of mean winter temperature as a constraint on SLF establishment, with activity dropping sharply at -3°C. This method for regional-scale ensemble modeling should be utilized in similar invasive or climate change SDM applications to make more refined SDM predictions and to reduce uncertainty. Viticulturalists can and should use our provided tools and model framework to understand the risk of SLF establishment at their locality as climate change removes barriers to this pest’s establishment globally. / Biology

Thesis (DPhil (Sociology and Social Anthropology))--Stellenbosch University, 2007. / There is a general consensus amongst industry experts that in order for the South African wine industry to sustain the success it has enjoyed thus far in export markets like the United Kingdom, the Netherlands and Sweden and to become even more internationally competitive, its has to improve the quality of its wine and move into higher price categories of the wine market. Skills’ training has been highlighted as a significant component of a strategy to improve the quality of South African wine and its competitiveness in world markets. The aim of this study was to find out how the South African wine industry is adapting to new vineyard practices necessary for quality production at farm level, especially as far as training of vineyard workers is concerned. Four theoretical perspectives are discussed in relation to the restructuring of the world agro-food industry, the question of quality and the issue of training as it relates the production of quality wine. These theoretical perspectives are regulation theory, global commodity chain analysis, actor-network theory and the ergonomics perspective on the skills needed for the production of quality wine. The focus of the study was on different kinds of producers, i.e. co-operative cellars, private cellars and estates. The research covered two of the main wine-producing areas, namely Paarl and the Robertson area. At each farm, interviews were conducted with the farm owner, farm manager or viticulturist as well as a number of workers. Interviews were also conducted with prominent wine makers, skills trainers and facilitators and other industry experts. This was done to gain a better understanding of the South African wine industry as well as the major issues and debates as far as quality production and skills training are concerned. The study found that although there has been a general upgrading of skills in relation to new vineyard practices for quality production, workers at the co-operatives and estates studied do not yet receive the kind of in-depth knowledge which the theory argues is necessary for the production of quality wine. The private cellars invest much more time and resources in the training of their workforce. As far as the private cellars and estates are concerned there is a correlation between the quality of wine and training. The private cellars sell more than 50% of their wine in the premium, super-premium, ultra-premium and icon categories of the international wine market. The estates sell 70% and more of their wine in the basic category. The co-operatives on the other hand do not confirm the theory. In the absence of formal training, they manage to produce wine that competes well on an inter and intra-regional level. The evidence suggests that in a country like South Africa, in the context of a legacy of low education and literacy levels amongst workers, repeated demonstration and strict supervision can compensate to a certain degree for a lack of in-depth knowledge and discretion amongst workers.

Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: The topic of landscape heterogeneity has captured the imagination of ecologists and agriculturists alike and has been extensively investigated in this dissertation. Heuweltjies are landscape features putatively created by the termite Microhodotermes viator through their burrowing and nest-building activities. They have been closely examined in the natural veld of the Western Cape in the recent past and are the focus of many ecological studies. However, the effect of heuweltjies in cultivated landscapes (e.g. vineyards, orchards and wheat lands) remains unexplored. This study contributes significantly to our understanding of soil modifications associated with heuweltjies, as well as the physiology of vines growing on and off heuweltjies and wine made from these vines. It was hypothesized that heuweltjies occurring in cultivated areas can significantly affect crop yield and quality, thereby establishing itself as a potentially important role player in the agricultural economy of the Western Cape. This study was conducted in two climatic regions of the Western Cape, Stellenbosch (Mediterranean climate, Cabernet Sauvignon) and Robertson (semi-arid climate, Shiraz) to better understand how differences in heuweltjie characteristics correspond to differences in rainfall and temperature. In both study areas, heuweltjie soils were compared to non-heuweltjie soils with respect to physical and chemical. Grapevines associated with these heuweltjies were also compared to those growing on the adjacent, non-heuweltjie soils to determine any variation in vine vigour, physiology, phenology, berry characteristics and wine quality. Through the use of ANOVA's and Fisher's LSD posthoc tests to indicate statistical significance in soil and grapevine characteristics, it was apparent that heuweltjies induce substantial changes in soil and vine properties. Significant differences in the water content exist between the soils of the heuweltjies and non-heuweltjie areas. Heuweltjie soils exhibited higher values in comparison to the non-heuweltjie soils in the Stellenbosch study area, with opposite results in Robertson. Heuweltjie soils also displayed higher exchangeable calcium and magnesium and higher total carbon and total nitrogen values than non-heuweltjie soils in both study areas. Differences in physiology were more subtle, but vine vigour was severely altered on the heuweltjie-associated vines, exhibiting excessive vegetative growth in Stellenbosch, leading to variations in berry characteristics on and off the heuweltjies. Again, the opposite was observed for Robertson. Lower sugar and alcohol percentages and higher titratable as well as malic acid concentrations were observed in the wines emanating from the heuweltjies in Stellenbosch. Sensory analyses proved significant, as lower astringency and alcohol burn were detected in the Cabernet Sauvignon heuweltjie wines than the non-heuweltjie wines in the Stellenbosch study area. Chemical differences in the wines from the Robertson study are were insignificant. However, a significantly lower fruitiness was observed in the Shiraz heuweltjie-wines when compared to the non-heuweltjie wines. Differences in soil water content between heuweltjies and its adjacent soils was the most influential factor in this study, and affected all of the soil-grapevine interactions to a large extent. Further research need to be conducted to better understand and clarify the reasons behind these variations, as well as possible effects of global warming on heuweltjie functioning in different climatic regions of the Western Cape. / AFRIKAANSE OPSOMMING: Die onderwerp van landskap heterogeniteit het die verbeelding van beide ekoloë en landboukundiges aangegryp en is op `n omvangryke wyse ondersoek in hierdie tesis. Heuweltjies is landskap eienskappe geskep deur die uitgrawe en nesbou aktiwiteite van die termiet Microhodotermes viator. Heuweltjies in die natuurlike veld is intensief bestudeer in die onlangse verlede en is die fokus van `n verskeidenheid ekologiese studies. In bewerkte landskappe (bv. wingerde, vrugteboorde en koringlande) is daar egter `n groot tekort aan navorsing oor die invloed van heuweltjies. Hierdie studie dra grotendeels by tot ons begrip van heuweltjie-geassosieërde grondverandering, asook die fisiologie van wingerd wat groei op en af van heuweltjies, sowel as die wyn afkomstig van hierdie wingerdstokke. Hipoteties sal heuweltjies in bewerkte areas die gewasopbrengs asook –kwaliteit betekenisvol beïnvloed en word so dus gevestig as `n potensieël belangrike rolspeler in die landbou-ekonomie van die Wes-Kaap. Die studie was onderneem in twee klimaatstreke van die Wes-Kaap, Stellenbosch (Mediterreënse klimaat, Cabernet Sauvignon) en Robertson (semi-ariede klimaat, Shiraz) om vas te stel hoe verskille in heuweltjie eienskappe ooreenstem met verksille in reënval en temperatuur. In beide studie areas is heuweltjie gronde met nie-heuweltjie gronde vergelyk met betrekking tot fisiese en chemiese eienskappe. Wingerdstokke geassosieër met heuweltjies is ook vergelyk met dié wat heuweltjies omring om enige variasie in groeikrag, fisiologie, fenologie, druifkorrel eienskappe en wynkwaliteit te bepaal. Deur gebruik te maak van ANOVA's en Fisher se LSD posthoc toetse om statistiese betekenisvolheid in grond- en wingerdeienskappe aan te dui, was dit duidelik dat heuweltjies wesenlike veranderinge in dié eienskappe teweegbring. Betekenisvolle verskille heers in die waterinhoud tussen die heuweltjie en nie-heuweltjie gronde. Heuweltjie gronde het hoër waardes getoon in vergelyking met die nie-heuweltjie gronde in die Stellenbosch studie area, met teenoorgestelde bevindings in Robertson. Heuweltjie gronde het ook `n hoër konsentrasie uitruilbare kalsium en magenesium, en totale koolstof en stikstof in vergelyking met nie-heuweltjie gronde. Verskille in fisiologie was baie meer subtiel, maar wingerd groeikrag was beduidend verskillend op die heuweltjie-geasossieërde wingerdstokke, met oormatige vegetatiewe groei in Stellenbosch wat lei tot `n verskil in druifkorrel eienskappe op en af van die heuweltjie. Weereens is die teenoorgestelde waargeneem in Robertson. Laer suiker en alkohol persentasies, asook hoër titreerbare - en appelsuur konsentrasies was te bespeur in die wyne afkomstig van die heuweltjies in Stellenbosch. Sensoriese analise het betekenisvolle verskille bewys, met `n laer vrankheid en alkohol-brand sensasie waargeneem vir die Cabernet Sauvignon heuweltjie wyne as die nie-heuweltjie wyne in die Stellenbosch studie area. Chemiese verskille in die wyne vanaf Robertson was onbeduidend. Sensoriese analise het egter anders bewys, met `n betekenisvolle laer vrugtigheid te bespeur in die nie-heuweltjie wyne as die heuweltjie wyne in die Robertson studie area. Verskille in die grondwaterinhoud tussen heuweltjies en omringende gronde was die mees invloedryke faktor in hierdie studie en beïnvloed tot `n groot mate al die grond-wingerdstok interaksies. Verdere navorsing is nodig om helderheid te verskaf agter die redes vir hierdie variasies, sowel as moontlike gevolge van aardverwarming op funksionering van heuweltjies in verskillende klimaatstreke van die Wes-Kaap.

Thesis (MscAgric (Viticulture and Oenology))--University of Stellenbosch, 2007. / The rapid expansion of the world wine industry has increased the pressure on wine producers to produce high quality, distinguishable wines. The use of sensory evaluation alone as a tool to distinguish between wines is limited by its subjective nature. Chemical characterisation using analytical methods and data analysis techniques are increasingly being used in conjunction with sensory analysis for comprehensive profiling of wine. Analytical chemistry and chemometric techniques are important and inextricable parts of the chemical characterisation of wine. Through this process insight into the inherent composition of wines, be it in a general sense or related to a particular wine category is gained. Data generated during chemical characterisation are typically compiled into electronic databases. The application of such information towards wine quality control includes the establishment of industry benchmarks and authentication. The current project is part of The South African Young Wine Aroma Project, a long term research initiative funded by the South African Wine Industry with the ultimate aim to establish a comprehensive, up-to-date, database of the volatile composition of young wines. The data generated during this thesis represent the first contribution towards realising this ambition. Three clearly defined aims were set for this project, the first of which is the chemical characterisation of South African young wines in terms of selected volatile and non-volatile compounds and Fourier transform infrared spectra, with particular focus on the volatile composition. FTMIR spectra are information rich and non-specific instrumental signals that could provide invaluable information of the inherent composition of the wines. The second aim is the evaluation of the analytical methods used to generate the data and in the last instance, the optimisation of FTMIR spectroscopy for rapid quantification of major wine parameters and volatile compounds. The concentrations of 27 volatile compounds in South African young wines were determined by gas chromatography coupled to flame ionisation detection (GC-FID) using liquid-liquid extraction of the analytes. Wine samples of the 2005 and 2006 vintages produced from six of the most important cultivars in the South African wine industry, namely Sauvignon blanc, Chardonnay, Pinotage, Cabernet Sauvignon, Merlot and Shiraz were used. The producing cellars were from four major South African wine producing regions, namely Stellenbosch, Paarl, Robertson and Worcester. The data captured made a significant contribution to the establishment of the Aroma Project Database. Univariate statistics showed wide variations in the chemical composition of the wines. Red wines were generally characterised by high levels of higher alcohols and white wines by high levels of esters. Most of the differences between vintages were cultivar dependent and phenological differences between cultivars were suggested as a possible cause. Fusel alcohols, iso-acids and esters of fusel alcohols were particularly responsible for differences between red wines. A combination of fatty acids and higher alcohols were responsible for differences between production regions. However, using univariate statistics alone was limited in identifying characteristic features of the chemical composition of the wines. In order to explore the correlations between the volatile components, FTMIR spectra and nonvolatile components the data were further investigated with multivariate data analysis. Principal component analysis was successfully employed to distinguish between wines of different vintages and cultivars. The role of the volatile composition was more influential in the separation of vintage and red wine cultivar groupings than the non-volatile components or the FTMIR spectra. Almost all the individual volatile components contributed to the separation between the vintages and cultivars, thereby highlighting the multivariate nature required to establish the distinguishing features pertaining to each of these categories. The FTMIR spectra and the non-volatile components were more important than the volatile components to characterise the differences between the white cultivars. It was not surprising that both the volatile components and the FTMIR spectra were needed to distinguish between both red and white cultivars simultaneously. It was of interest the full spectrum, including all wavenumbers were required for a powerful classification model. This finding supports the initial expectation that the non-selective but information rich signal captured in the FTMIR spectra is indispensable. No distinction could be made between the production regions, which was not surprising since the wines used in this study was not of guaranteed origin. Furthermore, no clear correlation could be established between the chemical composition or the FTMIR spectra and the quality ratings of the wines. Limitations in the dataset were pointed out that must be taken into account during further investigations in the future. The liquid-liquid extraction method used during the analysis of the volatile components was evaluated for precision, accuracy and robustness. Generally good precision and accuracy were observed. There were slight indications of inconsistencies in the recoveries of analytes between the red and white wine matrices. Certain parameters of the protocol, namely sample volume, solvent volume, sonication temperature and sonication time, were identified as factors that had a major influence on quantification. The results obtained in this study made a major contribution towards establishing this technique for routine GC-FID analysis in our environment. Due to the high sample throughput in wine laboratories, the use of rapid quantitative analytical methods such as FTMIR spectroscopy is becoming increasingly important. Enzymatic-linked spectrophotometric assays and high performance liquid chromatography (HPLC) methods were evaluated for their suitability to serve as reference methods for optimising and establishing FTMIR calibrations for glucose, fructose, malic acid, lactic acid and glycerol. Pigmented and phenolic compounds were identified as sources of interference in the determination of organic acids in red wines with both enzymatic assays and HPLC. The use of fining treatments for the decolourisation of red wine samples was investigated. Activated charcoal was more efficient in terms of colour removal than polyvinyl polypyrrolidone (PVPP), but neither were compatible with the specific enzymatic method used in this study. Solid phase extraction (SPE), a method commonly used during sample clean-up prior to HPLC analysis of organic acids in wine, and PVPP fining were evaluated as sample preparation methods for HPLC analysis to optimise the quantification of organic acids in red wine. Four different types of SPE cartridges were evaluated and the SPE method was optimised in order to recover the maximum amount of organic acids. However, low recoveries, in some instance less than 50%, for the organic acids in wine were reported for the optimised SPE method. In this respect one was the worst. On average, excellent recoveries were observed for the organic acids using the PVPP method that were in excess of 90%. This method therefore provides a very valuable and simple alternative to SPE for sample-cleanup prior to HPLC analysis. One aspect that still needs to be investigated is the reproducibility of the method that should still be optimised. In general, enzymatic analysis was more suitable for the determination of glucose and fructose, while HPLC analysis were more suitable for the quantification of organic acids. Efficient glycerol quantification was observed with both enzymatic and HPLC analysis, although a lower measurement error was observed during the HPLC analysis. Apart from reliable reference methods, successful FTMIR calibrations also rely on the variability present in the reference sample set. The reference sample set used to establish FTMIR calibrations must ideally be representative of the samples that will be analysed in the future. Commercial, or so-called global, FTMIR calibrations for the determination of important wine parameters were evaluated for their compatibility to a South African young wine matrix. The prediction pH, titratable acidity, malic acid, glucose, fructose, ethanol and glycerol could be improved by establishing a brand new FTMIR calibration, thereby clearly indicating that the South African young wine matrices were significantly different from the samples of European origin that were used to establish the commercial calibrations. New preliminary calibration models were established for a young wine sample matrix and were validated using independent test sets. On average the prediction errors were considered sufficient for at least screening purposes. The effect of wavenumber selection was evaluated. Relatively successful models could be established for all the compounds except glucose. Wavenumber selection had an influence on the efficiency of the calibration models. Some models were more effective using a small amount of highly correlated wavenumbers, while others were more effective using larger wavenumber regions. Preliminary FTMIR calibration models for the screening of volatile compound groups in young wines were evaluated. Compound groups were compiled based on chemical similarity and flavour similarity. Good linearity were observed for the “total alcohol”, “total fatty acids”, “esters” models while an interesting polynomial trend was observed for the “total esters” model. Relatively high prediction errors indicated the possibility of spectral interferences, but the models were nevertheless considered suitable for screening purposes. These findings are a valuable contribution to our environment where fermentation flavour profiles must often be examined. The important role sound and validated analytical methods to generate high quality analytical data, and the subsequent application of chemometric techniques to model the data for the purpose of wine characterisation has been thoroughly explored in this study. After a critical evaluation of the analytical methods used in this study, various statistical methods were used to uncover the chemical composition of South African young wines. The use of multivariate data analysis has revealed some limitations in the dataset and therefore it must be said that wine characterisation is not just reliant on sophisticated analytical chemistry and advanced data analytical techniques, but also on high quality sample sets.