### Author Topic: How do I calculate attenuation?  (Read 1066 times)

#### M-O-O-N That spells beer!

• Assistant Brewer
• Posts: 135
• South Jersey
##### How do I calculate attenuation?
« on: March 27, 2017, 02:54:36 AM »
I apologize if this has been asked before, or if this is a 'stupid' question, but how does one figure attenuation of yeast?

Safale 04 has Min Attenuation 72% and a Max Attenuation 75%
If the SG is 1.066, how do I figure FG? I know the answer is right in front of me but I just cannot grasp it.

Na zdrowie!

#### JT

• Senior Brewmaster
• Posts: 1527
• Bloatarian Brewing League - Cincinnati, OH
##### Re: How do I calculate attenuation?
« Reply #1 on: March 27, 2017, 04:38:31 AM »
Final Gravity = 1 + ((Total Gravity Points * (1 - Attenuation Percent)) / 1000)

1+((66*(1-.72))/1000) = 1.01848
1+((66*(1-.75))/1000) = 1.0165

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#### HoosierBrew

• I must live here
• Posts: 13031
• Indianapolis,IN
##### Re: How do I calculate attenuation?
« Reply #2 on: March 27, 2017, 02:27:30 PM »
OP - Keep in mind that your attenuation may well NOT lie in between those minimum and maximum attenuation numbers. And if so, that doesn't mean you did anything wrong -they are rough guidelines at best that don't take into account your mash temp(s), grist, yeast health/viability, pitching rates, aeration at pitching, etc. I often exceed stated attenuation ranges depending on what I'm brewing.
Jon H.

#### M-O-O-N That spells beer!

• Assistant Brewer
• Posts: 135
• South Jersey
##### Re: How do I calculate attenuation?
« Reply #3 on: March 27, 2017, 10:49:08 PM »
Thanks for the help! This will also be useful when using Brulosophy's Lager method.
Na zdrowie!