A critical process analysis of wine production to improve cost efficiency, wine quality and environmental performance

[摘要] ENGLISH ABSTRACT:Wine cellars are diverse in terms of equipment types and process configurations. Whilstother food production processes have, in many cases, been properly analysed andmodelled, this process diversity has resulted in an absence of process analyses in thewine industry. Each wine cellar is unique and represents a fully integrated agro-business,starting with a raw material (grapes) and extending to marketing and selling of the finalproduct (wine). This makes the wine industry unique in this context. This study is the firstattempt to analyse winemaking procedures in the form of a process audit.The study was approached in the following manner:• A questionnaire was developed to assess cellar configurations and conditions. Thisquestionnaire was submitted to a statistically significant number of cellars, and astatistically significant number of questionnaires were returned.• The data collected from the questionnaire were statistically analysed andassociations between equipment or procedures and wine faults were identified.• Three cellars were studied in depth. These three cellars had their processesaudited and their effluent characterised. Additional data were obtained from currentsampling projects and these data were analysed to complement the data obtainedfrom the questionnaire• A preliminary input/output model was developed.The major results of this study are:• It was found that certain faults that appear in wine might be associated withequipment and/or process faults. These associations are statistically significantand they show that cellar hygiene is of critical importance when assessing thesewine faults. The most important of these faults are VA, microbial contaminationof the wine, sluggish and stuck fermentations. A risk hierarchy was derived toindicate which events are associated with others most strongly.• It was found that few wineries measure water consumption and even fewerwineries measure the quantity of effluent produced.• Correlations have been developed to predict winery parameters in terms of tonsof grapes pressed per annum. These parameters include water and electricityconsumed, wine produced and the quantity of effluent produced. Effluentcharacteristics have also been correlated to the tons of grapes pressed perannum. These characteristics include chemical oxygen demand, sodiumabsorption ratio and total dissolved solids in solution. Chemical oxygen demandwas identified as the most important contributing factor in winery effluent. It wasshown that all variables rise with an increase in cellar size, but the rise is not linear. This implies that large cellars have greater quantities of effluent of lowerquality than small cellars. Most cellars have effluent concentrations that requiresome form of effluent treatment. The characterisation of effluent shows that themost widely used disposal practice is irrigation, and that the effluent disposed inthis manner does not meet legislative requirements.• A preliminary input/output model was developed in order to enable wineries thathave not measured the relevant parameters to predict the abovementionedvariations. The resolution of these predictions is low but the model serves toprovide an initial estimate if there are no data available. The model will giveindustrial averages for any given cellar size.• An economic balance was performed using this preliminary model. It wasshown that if cellars were to lower the consumption of utilities and to reduce thestrength of their effluent (using cleaner practices and not dilution) the reductionof operating costs could be reduced by 14% for smaller cellars to 17% for largercellars.This study has shown that it is possible to make wine in a more environmentallyfriendly manner, producing better quality wines, without incurring extra costs.

[发布机构] Stellenbosch University