The Fermentation Process in Wine Making
Wine making is a long process. After the best grapes have been harvested and pressed they have to go through a process called fermentation. During pressing, when the grapes’ skins are broken, yeast, or Saccharomyees ellipsoideus, from the skins comes in contact with the sugar from the insides of the grapes.
The yeast enzymes convert the sugar into alcohol and carbon dioxide. They also make various by-products that may add to the wine’s flavor and aroma. The carbon dioxide escapes into the air, but the alcohol stays in the grape juice, or must.
The longer the must ferments the less sugar it will contain. Dry wines are made by letting complete fermentation take place. This lets the yeast change all the sugar into alcohol. If fermentation is stopped, there will be more sugar left in the wine, and it will be sweeter.
Sparkling wines are made by adding more sugar and yeast to the wine after it has been transferred to bottles. A second fermentation builds up carbon dioxide in the bottles and this then produces the bubbles.
Fermentation gives off heat, so most wineries refrigerate the must so the temperature stays constant throughout the process. White wines are usually kept at about 59|F, and red wines are kept at around 86|F. The higher temperature in the red wine allows the color and flavor of the skins to transfer to the wine.
The Term Paper on An Investigation Into the Effects of Sugar Concentration on Yeast Activity
An investigation into the effects of sugar concentration on yeast activity Introduction: Yeasts are eukaryotic micro organisms belonging to the kingdom fungi. Yeasts live on sugars and produce ethanol and carbon dioxide as by-products. [James Mallory, 1984]When Yeasts are given water and sucrose they convert the sucrose into glucose then convert the glucose into carbon dioxide and ethanol ...
Yeast isn’t only used in wine making. It is a very useful fungus.
