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  • Essay / The Chemistry of Alcohol - 1138

    Alcohol is a class of organic compounds characterized by the presence of one or more hydroxyl groups (-OH) attached to a carbon atom. Alcohol was unknowingly produced centuries ago during the fermentation of crushed grapes (Pines, 1931). In today's society, alcohol is produced for the use of household products such as varnishes and cleaning products, but it is of greater commercial importance in the alcoholic beverage sector. A chemical process called fermentation achieves the production of ethanol, alcohol or alcohol. From there, ethanol goes through separate processes to become the dark and light liquors on store shelves. The alcoholic fermentation process begins with the use of enzymes. The enzymes begin to break the long chains of starch molecules, a polysaccharide consisting of a large amount of glucose molecules (C6H12O6) linked by glycosidic bonds as shown in Figure 1, into single molecules of glucose, a monosaccharide with six carbons and five hydroxyls. groups. Once the starch has become sugar, enzymes are used again, this time to convert the sugars into ethyl alcohol and carbon dioxide, CO2, as shown in Figure 2 (World of Scientific Discovery, 2007). The carbon dioxide produced is released into the atmosphere, leaving behind water and ethanol, alcohol. Ethanol is a colorless, flammable liquid with the molecular formula C2H6O, giving it a molar mass of 46.07 grams per mole. Ethanol is also characterized by a melting point of -114°C or 159 K. All types of alcohol go through a fermentation process. When looking at beer production, the fermentation process contains a series of distinct steps. Beer has four main ingredients; a type of grain (wheat, corn, barley), hops, water and yeast. The beer-making process begins with the malting process, the stage where the grain is soaked in water for days to allow adequate germination time. This process is important because allowing the grain to germinate produces enzymes needed to break down the starch in subsequent stages. Sometimes the conversion of starch to sugar can begin during malting due to enzymes present in the grain, but the majority of conversions begin at the next stage (Michaels, 2010). After the malting process, the grains go through a process called mashing, defined as the stage where the grain is hydrated, which causes enzymes to activate and begin converting starches into sugars. During the brewing stage, enzymes are activated and begin to convert starch into sugars which will eventually go through the fermentation process..