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General Category => Yeast and Fermentation => Topic started by: bboy9000 on February 17, 2013, 04:46:55 PM

Title: Manufacturer Attenuation Figures
Post by: bboy9000 on February 17, 2013, 04:46:55 PM
Do yeast manufacturers post actual attenuation or apparent attenuation figures for yeast strains on their websites?  Neither the Wyeast FAQ's page nor quick searches on Google and the AHA forum gave me the answer.
Title: Re: Manufacturer Attenuation Figures
Post by: hopfenundmalz on February 17, 2013, 05:05:51 PM
Click on any strain and you will find the attenuation.
http://www.wyeastlab.com/hb_yeaststrain.cfm

You can just scroll for White labs.
http://www.whitelabs.com/beer/homebrew_strains.html#ALE_YEAST
Title: Re: Manufacturer Attenuation Figures
Post by: denny on February 17, 2013, 05:10:13 PM
Do yeast manufacturers post actual attenuation or apparent attenuation figures for yeast strains on their websites?  Neither the Wyeast FAQ's page nor quick searches on Google and the AHA forum gave me the answer.

Well, actually kinda neither.  The figures that manufacturers publish are simply a way of comparing on strain to another using a standardized wort.  They may or may not be an indication of the attenuation you can expect.  That's dependent on things like recipe and techniques.
Title: Re: Manufacturer Attenuation Figures
Post by: bboy9000 on February 17, 2013, 05:16:59 PM
I should've been more clear.  I was referring to whether these figures were actual or apparent.  So it looks like neither.  Are the manufacturer provided attenuations even useful for comparison with my apparent attenuation?
Title: Re: Manufacturer Attenuation Figures
Post by: tygo on February 17, 2013, 06:19:13 PM
It's apparent attenuation but as Denny said it's only really useful for comparing one strain to another on paper.
Title: Re: Manufacturer Attenuation Figures
Post by: denny on February 17, 2013, 06:38:26 PM
I should've been more clear.  I was referring to whether these figures were actual or apparent.  So it looks like neither.  Are the manufacturer provided attenuations even useful for comparison with my apparent attenuation?

Not IMO.  OK, maybe a bit....personally, though. I don't even look at or consider the manufacturer figures.  I can get 60% or 90% attenuation out of the same yeast depending on the wort.
Title: Re: Manufacturer Attenuation Figures
Post by: hopfenundmalz on February 17, 2013, 07:14:59 PM
I see I should have had more coffee.
Title: Re: Manufacturer Attenuation Figures
Post by: woodlandbrew on February 18, 2013, 03:32:31 PM
Agreed with the other posters here.  The number is apparent attenuation, but it's more if a relative measurement.  You could likely get close to that if you mash at 150°F, pitch 10 million cells per ml into a 10°P wort and ferment at 20°C, but chances are that's not the beer you are going for. 

Recently I did a matrix of 40 fermentations with wort gravities from 3°P to 15°P and inoculations rates from 30 million per ml to 120 million per ml and was quite surprised by the variation in attenuation.

Data will be on my blog soon.
Title: Re: Manufacturer Attenuation Figures
Post by: denny on February 18, 2013, 03:44:23 PM
Agreed with the other posters here.  The number is apparent attenuation, but it's more if a relative measurement.  You could likely get close to that if you mash at 150°F, pitch 10 million cells per ml into a 10°P wort and ferment at 20°C, but chances are that's not the beer you are going for. 

Recently I did a matrix of 40 fermentations with wort gravities from 3°P to 15°P and inoculations rates from 30 million per ml to 120 million per ml and was quite surprised by the variation in attenuation.

Data will be on my blog soon.

Looking forward to seeing it.