Essay On Wine Quality

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Background: FACTORS AFFECTING WINE QUALITY The quality of wine is determined by a number of interrelated variables which take effect during the fermentation process. The variables that have the most significant effect are as follows; the pH of the wine, the temperature at which the fermentation process is transacted, the alcohol and CO2 percentage present post fermentation, the amount of SO2 (sulphur dioxide) present in the solution and the wines titratable acidity. Overview of each variable: The pH is a measure of the amount of acids present in the solution, it differs determining on the strength of these acids and may also change depending on the other miscellaneous ingredients added to the wine with any degree of acidity. For wine specifically, the pH is determined on three main variables: the amount of potassium added, the total amount of acid present and the ratio between malic acid to tartaric acid. The optimum temperature for the fermentation process is 20 degrees which allows the yeast to accumulate unhindered. Because fermentation is an exothermic process (releases heat) it must be kept under constant surveillance. The temperature in which the formation process is heated controls the different tastes of wine (from fruity to artificial). For Red wines, the optimal temperature concludes at 25-300C (this includes the heat released from the fermentation process) in which yeast is fermented at its maximum and most efficient rate (because of particle movement). Post the fermentation process, the amount of alcohol present is a main control of the taste and quality of each wine; creating preference. Fermentation (more specifically ethanol fermentation) is the process in which pyruvate (from glucose metabolism (carbohydrates)) is ... ... middle of paper ... ...hen hypothesised that if the pH is reduced drastically, it could be assumed that there exists an excess amount of malic acid in which case (as explained above) the wine would be dull and plain because of the lack of flavour, also no or limited bacteria life would be present. Also it is hypothesised that if the pH were to increase it would cause an influx in ethanol and CO2 levels will also increase during fermentation due to Hetrofermentive bacteria growth and their presence during the process (as explained above). These results would be determined based on the concentration of acidity in the final solution of wine which has been determined to be based on the amount of tartaric and malic acids present (90% of the wines acidity in composed of these two acids). Therefore the less of these acids there are present in the wine the higher the pH will rise, and vice versa.

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