Fermentation is a process that is carried out in certain living organisms which have limited or null amount of oxygen, it’s done when an organism does anaerobic respiration. The organism will release the energy stored in between the links that hold the Carbons there will be energy release and ethanol or lactic acid.
Fermentation has been discovered tobe very useful in the different industries. Their capacity to help in the different industries was first discovered in Babylon circa 5000 BCE used in the beverage industry. Wine has been one of the most present beverages in which its production needs the process of fermentation.
Fermentation for winemaking is the most important step. The effects of alcohol were discovered when rotten fruit wereconsumed and had an intoxicating effect, as well this fermented liquid could be stored a lot of time without decomposing.
The processes used for winemaking are different depending on the kind of wine you want to get, the use you are going to give to the wine and the place were the process will be carried out. The process used for getting white wine will follow the next steps: first the grapeswill have to be picked up from the vineyard; usually the types of grapes used are Vitis Vinefera because they have high amounts of glucose (sugars). The grapes will need to be clean and free of any bacteria that may cause any disastrous results; this step will be done with the help of a caustic solution based on O₂, 10 gallons of water per each gallon of wine produced, and anti-bacterial sulphitesolution.¹ Then the grapes are treated to eliminate any unwanted microorganisms or wild yeast.
Immediately after the grapes have been cleaned they have to be taken to a winepress which is a container that will gently squash the grapes for a certain time, the extracted juice from the grapes will be send to a holding container. In the holding container the juice will be cooled and the left fruitwill be removed to prepare the juice for fermentation process.
The juice is now transferred to fermenting vats, at the same time the yeast is added, the yeast is a domesticated one, which has suffered certain changes to make a much better wine, it has adapted to work in presence of sulphur dioxide which will be present to kill the most common bacteria in fermentation and to master before thewild yeast that might be still present in the grapes, with this adaptations the fermentation will occur without a hitch and kind of controlled by winemakers. In this fermenting vats air is taken out, like this there won’t be oxygen so that fermentation will happen correctly, and oxidation won’t happen and won’t let bacteria grow. The process of fermentation will occur because there is no oxygenpresent in the fermenting vats, so the yeast cells will have to perform anaerobic respiration, the yeast cells will convert the sugars in the juice of the grapes to ethanol and unintentionally carbon dioxide. The resultant wine will have a concentration of about 12 – 15% of ethanol, because yeast cells may not survive to higher concentration, the average temperature in which the fermenting vats willbe is of 25°C because that’s around the perfect temperature in which the yeast cells will work the best, the process of fermentation is slow and takes about 10 to 30 days. In certain white wines a second fermentation might occur, it is good when it occurs because it has a wine changing from crisp and light to creamier buttery. It may occur spontaneously or done by the winemaker. When the grapesare not yet mature, they will have a malic acid and this secondary fermentation will turn malic acid to lactic acid, and reduce the acidity of wine.
When fermentation process is completed the wine is extracted and separated from dead yeast cells it is then cooled down and bottled.
Fermentation is the most important step...