Attenuation (brewing) Attenuation (brewing) In brewing, attenuation is the percentage that measures the conversion of sugars into alcohol and carbon dioxide by the fermentation process; a more attenuated beer will generally be drier and more alcoholic than a less attenuated beer made from the same wort. The percentage is calculated by comparing weight or specific gravity of the extract before and after fermentation. the following iteration,Attenuation = 100 % * (starting gravity − current gravity) / (starting gravity − 1) is meaningless This formula works with extract given in weight percentages or degree Plato. Extract refers to all the non water substances
Low-alcohol beer brews used at festivities. More recently, the temperance movements and the need to avoid alcohol while driving, operating machinery etc led to the development of non-intoxicating beers. In the United States, non-alcoholic brews were promoted during Prohibition, according to John Naleszkiewicz. In 1917, President Wilson proposed limiting the alcohol content of malt beverages to 2.75% to try to appease avid prohibitionists. In 1919, Congress approved the Volstead Act, which limited the alcohol content of all beverages to 0.5%. These very low alcohol beverages became known as tonics, and many breweries began brewing them in order to stay in business during