Beer originated almost 6000 years ago. It is made by brewing and fermenting starches or cereal grains like barley, rice, wheat, corn, etc., with malt, water, sugar, and yeast. The water-content is about 90%. Beer is flavored with hop, the flower of hop-vines. It gives beer its distinct bitter taste and it also acts as a preservative. Brewing is an art. Beer has been a part of the culture and tradition of many countries for thousands of years.
Alcohol in Beer
Yeast helps the process of fermentation as they convert the sugars in the wort (liquid at the initial stage of preparation) into alcohol. The types of beer are determined by the type of yeast used to ferment the product. The average alcohol content of beer ranges from 4 to 6%. The maximum amount present can be 20%, but such types are rarely consumed. These days, you get variants with 1% alcohol. This can be the minimum level. According to the law, the varieties containing less than 0.5% alcohol are called non-alcoholic beers. Knowing the amount of alcohol helps one to know the number of calories in the drink. Beers that are high in alcohol are also high in calories. To enjoy the health benefits of beer, you should opt for low calorie varieties.
|Name/Type of the Beer||Percentage of Alcohol Content|
|Extra Gold Lager||4.97|
|Stone Old Guardian||9.9|
Determining the Alcohol Content in Beer
The specific gravity of a beer measures the density of beer relative to water. The specific gravity of the liquid before it starts fermenting is compared with its specific gravity after it finishes fermenting. For example, the density of water is 1 kilogram per liter, so if the specific gravity is 1.04, one liter of the beer will weigh 1.04 kg. The specific gravity of the wort is higher than water. As alcohol is less dense than water (0.79 kg/liter), the specific gravity of the final product 'beer' is less than the specific gravity noticed at the initial stage of preparation. Mainly, glucose (C6H12O6) gets converted to alcohol. Yeast, after initiating many chemical reactions, ultimately converts each glucose molecule into two molecules of ethyl alcohol (CH3CH2OH) and two molecules of carbon dioxide (CO2). Here is the formula for the chemical reaction.
C6H12O6 = 2 (CH3CH2OH) + 2 (CO2)
The molecular weight of ethyl alcohol (CH3CH2OH) is 46.0688 and the molecular weight of carbon dioxide is 44.0098. As each molecule of glucose splits into 2 carbon dioxide molecules and 2 ethyl alcohol molecules, the process implies that 'for each 44.0098 grams of CO2 that leaves the vessel 46.0688 grams of ethyl alcohol are formed' or 'for each gram of CO2 that bubbles off, about 1.05 grams of ethyl alcohol are produced'. Suppose, the starting specific gravity of the wort is 1.06 and that of the beer after fermentation is 1.02, then subtraction gives you the amount of CO2 left. It is 0.04 kg/L. Multiply it by 1.05, to get the weight of the alcohol in the container. That is 0.042 kg/L. Dividing mass of the alcohol by mass of the solution, i.e., 0.042/1.02 gives you the percentage by mass which in this case is 0.041 or 4.1 percent. Remember, the percentage of alcohol by mass is higher than the percentage by volume. If you want to convert the percentage by mass to the percentage by volume, you should divide the percentage by mass by the density. Here, it is 4.1/0.79 or 5.2 percent alcohol by volume.
After reading such minute details about the alcohol in beer, you really deserve your favorite drink. However, now you will be more responsible. So, just go ahead and grab a mirthful mug!!