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Attenuation question

How do you calculate your attentuation? Just trying to figure out if I am getting what I should out of my yeast or if I need to make a better effort to control the fermentation temps better. I usually keep them in range but sometimes they get outside it for s short time.

(og-fg) / (og-1) = aa%

Be aware that the manufacturer’s published attenuation means nothing when applied to your particular wort - it’s just for comparing one yeast to others made by the same manufacturer since the attenuation was determined under laboratory conditions. So if WY1111 has an attenuation of 65-70% and WY1234 says 75-80%, you only know that 1234 is predicted to be more attenuative than 1111 given similar wort composition.


If you have brewing software you can manipulate the attenuation% once you have FG. It works for me on Brew Tools if I have hit my OG or adjusted my efficiency afterwards to have the right OG entered. I use a stir plate and pitch very healthy volumes of yeast and together with good brewing practices regularly get attenuation rates in excess of what is advertised. As the previous post stated, the advertised rates just give you an idea of what one yeast will do relative to another in the same wort.

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