Alcohol Content Of Beer

Beer originated almost 6000 years ago. It belongs to the category of alcoholic drinks. It is made by brewing and fermenting starches or cereal grains like barley, rice, wheat, corn, etc., with malt, water, sugar and yeast. Water-content in beer is about 90%. Beer is flavored with hop, the flower of hop-vine. It gives beer the distinct bitter taste and it also acts as a preservative. Beer brewing is an art. Beer has been a part of the culture and tradition of many countries for thousands of year.

Alcohol in Beer

The yeast help the process of fermentation as they convert the sugars in the wort (liquid at the initial stage of preparation of beer) 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 of alcohol present in beer can be 20%, but such beer is very rarely consumed. These days, you get beer with 1% alcohol. This can be the minimum level of alcohol found in beer. According to the law, beers containing less than 0.5% alcohol are called non-alcoholic beers. Knowing the amount of alcohol in beer helps know beer calories. Beers that are high in alcohol are also high in calories. To enjoy health benefits of beer, you should opt for low calorie beers.

Name/Type of the Beer	Percentage of Alcohol Content
Extra Gold Lager	4.97
Amstel	3.9
Amstel Light	3.5
Amber Ale	5.5
Alaskan Stout	5.7
Pilsner	5.3
Merzen	5.7
Stone Old Guardian	9.9
Lager	4.41
Hammerhead	5.8
Beck's Beer	5

How to Determine Alcohol Content of Beer

The specific gravity of the beer before it starts fermenting is compared with its specific gravity after it is finished fermenting. The specific gravity of a beer measures the density of beer relative to water. For example, the density of water is 1 kilogram per liter, so if the specific gravity of a beer 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 actual 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 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 gravity of the wort is 1.06 and the gravity of the beer after fermentation is 1.02, then subtraction gives you the number 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 of alcohol 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 of alcohol by volume. If you want to convert the percentage of alcohol by mass to percentage of alcohol by volume, you should divide the percentage by mass by the density of alcohol. 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. So just go ahead and grab a mirthful mug!!