With the addition of yeast the term wine can now be

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Unformatted text preview: lfur dioxide. This process is called sulfating, and inhibits the unwanted microorganisms and wild yeast species on the grapes. Sulfur dioxide plays two important Sulfur dioxide roles. Firstly, it is an anti­microbial agent, and as such is used to help curtail the growth of undesirable fault producing yeasts and bacteria. Secondly, it acts as an antioxidant, safeguarding the wine's fruit integrity and protecting it against browning. White Wine White Wine Pressing the grapes Grapes that are meant for the production of Grapes white wine are picked and immediately processed white in the winepress. The grapes are gently squeezed in for about 2 hours and the juice is pumped (or fed by gravity) into holding tanks. In the tanks, the juice is chilled, and sediment from the fruit drops to the bottom. The sediments are removed and wine is ready to be fermented with yeast. wine Fermentation The juice is transferred to fermenting vats, and the yeast is added. With the addition of yeast, the term wine can now be used to describe the grape juice. The species of yeast that is used to ferment grape juice into wine is Saccharomyces cerevisiae. This yeast is a domesticated species that has been acclimatized to the effect of free sulfur dioxide. In case some wild yeast still exists in the juice, the domestic species can dominate and the fermentation will be able to proceed in a predictable fashion. The juice is put in large vats from which air The juice is put in large vats from which air is excluded. In this way, oxidation is prevented and the growth of bacteria is discouraged. The most problematic bacterium is of the genus Acetobacter. This organism has the potential to convert wine into vinegar (acetic acid) overnight. Fortunately, Acetobacter is sensitive to free sulfur dioxide and preventative measure against the bacteria can be taken. Fermentation is a process that takes place slowly over a period of ten to thirty days. The temperature of the liquid is maintained at approximately 77oF, as severe changes in temperature can kill the...
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This document was uploaded on 03/10/2014 for the course AGRO 1001 at LSU.

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