Attenuation

[OldGazza]

Is there a simple-ish calculation for working out the attenuation of your brew.
Looked at one site online and equation gave me headache at first site. I'me just a simple ale drinker with a 50p calculator.

 

[Wez]

I think I know what you mean, let me know if I misunderstood.

To work out the attenuation that you have achieved use this simple formula

starting gravity (minus) current gravity (divide by) starting gravity (multiply by) 100

So if your Starting Gravity is 1.060 and your current gravity is 1.016 it would look like this:

60 minus 16 = 44
44 divide by 60 = 0.73
multiply by 100 = 73

In this example you have achieved 73% attenuation

So if the yeast you are using tells you on the packet that it achieved 70% attenuation you can work out what your final gravity should be (i.e. 30% of your SG)

If you have a SG of 1.050 using a 70% attenuating yeast you work it out as follows

50 multiply by 0.30 = 15 (1.015)

Or if your yeast says it will attenuate by 73% the example would be:

50 multiply by 0.27 = 13.5 (1.013.5)

Hope that has helped, maybe we can add a calc :hmm:

 

[OldGazza]

Thats what i was after ,cheers !!!

 

[Wez]

Nice one OG :thumb:

 

[Rabmaxwell]

This calculates the attenuation for you http://fexr.com/5m5y

 

[MEB]

So does Wez if you ask him. :lol:

 

[jamesb]

So does Wez if you ask him. :lol:

Special Offer! Free e-mail addresses with every attenuation figure! :lol:

 

[J_P]

Sorry to throw a Spaniard in the works here but has anyone else found attenuation (apparent or otherwise) a load of codswallop? I've had Nottingham, Windsor and S04 do way over their quoted attenuation in dark and light ales alike.

It doesn't seem to matter a jot what temperature I mash at or how many dark grains I add the only way to be sure to achieve your desired final gravity is to monitor it and fine the yeast out when you're at the gravity you want.

I have a laboratory hydrometer so accurately measuring the gravity isn't the issue, any ideas?