Sat Jun 19, 2010 7:40 pm
Go to the yeast supplier's web site and check the expected attenuation for the strain you are using. It will be specified as a range, for example, 73 - 77% (Wyeast 3068). If your actual numbers fall within that range then the yeast are doing what they are supposed to do. If you have, for example, 50% apparent attenuation for a strain that is supposed to produce 73 - 77% then something is wrong such as insufficient cells pitched, insufficient oxygen, insufficient FAN or other yesast nutrient, inactive yeast (it happens), cells killed or damaged by pitching into wort that was too hot, fermentation temperature too cold, haven't given them enough time...
