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
Brewing of time; brewing yeast strains act slower, but tend to tolerate higher alcohol concentrations (normally 12–15% abv is the maximum, though under special treatment some ethanol-tolerant strains can be coaxed up to around 20%). Modern quantitative genomics has revealed the complexity of "Saccharomyces" species to the extent that yeasts involved in beer and wine production commonly involve hybrids of so-called pure species. As such, the yeasts involved in what has been typically called top-cropping or top-fermenting ale may be both "Saccharomyces cerevisiae" and complex hybrids of "Saccharomyces cerevisiae" and "Saccharomyces kudriavzevii". Three notable ales, Chimay, Orval and Westmalle, are fermented