Upon completion of fermentation, a certain amount of CO2 remains in the beer. This amount of "residual CO2" depends upon the temperature of the fermentation. An ale fermented at 65°F will have 0.9 volumes of residual CO2 while a lager fermented at 50°F will have 1.2 volumes. To get the same carbonation in these two beers would require different amounts of priming sugar.
For the same weight, the various priming sugars generate different amounts of CO2. To add one volume of CO2, you need to add priming sugar at the following rates:
Please note that DME varies in its fermentability. Some example brand names are given with their approximate apparent attenuation (AA) values. Typically, DME has an AA of 70% to 75%, with the notable exception of Laaglander brand at 55%.
CautionPlease exercise caution in using the results from this calculator. If the amount of priming sugar recommended seems excessive then use common sense and only use the amount you're accustomed to using, because it's quite likely you made a mistake when entering your numbers. Too much priming sugar or bottling a batch of beer that is not done fermenting can cause exploding bottles! Also, some bottles are capable of holding more pressure than others, so don't carbonate bottles to higher pressures than the beer that came in them. This information is provided "as is" and the author assumes no liability for the use of the results from this calculator.
This widget is based on information from the following articles, for which I am indebted to the authors:
Note: The priming rates used here differ somewhat from those mentioned in Hibberd's and Draper's articles. For instance, Draper measures volumes of CO2 using 20°C as the reference temperature instead of 0°C as in Hall's article. I'm using Hall's convention here.
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© Copyright 1998 Mark Riley, All Rights Reserved.