| Author |
Message |
   
Bierview
Advanced Member Username: Bierview
Post Number: 607 Registered: 03-2003 Posted From: 67.85.0.212
| | Posted on Wednesday, October 28, 2009 - 05:42 pm: |
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Just racked an Imperial Stout with an OG of 1.095 FG 1.020. That gives me about an attenuation rate of 79%. I was dissapointed with that until I looked at the stats of the yeast W1728. It gives this yeast between 69-73%. Still.........could I have dropped it further? |
   
Marc Rehfuss
Member Username: Marc_rehfuss
Post Number: 134 Registered: 03-2003 Posted From: 199.133.212.53
| | Posted on Wednesday, October 28, 2009 - 06:18 pm: |
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Depends on several factors. How big of a starter did you pitch? Did you oxygenate? What temperature did you mash at? How many grains that contribute unfermentables (e.g. crystal and/or dextrin malt) are in your grist? I find I can almost always push my yeast past what manufacturers list if I give my yeast a fermentable wort. With that strain, I'd say you are done. That really is excellent attenuation for that strain, let alone in a impy. Good work. (Message edited by Marc_rehfuss on October 28, 2009) |
   
Denny Conn
Senior Member Username: Denny
Post Number: 7295 Registered: 01-2001 Posted From: 75.145.77.185
| | Posted on Wednesday, October 28, 2009 - 06:33 pm: |
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Yeast attenuation rating make a lot less difference than the fermentability of the wort. |
   
Bill Pierce
Moderator Username: Billpierce
Post Number: 10875 Registered: 01-2002 Posted From: 24.141.103.148
| | Posted on Wednesday, October 28, 2009 - 07:50 pm: |
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Denny's correct that other factors have even more influence than the yeast strain in terms of attenuation, but I have to give the nod to Marc here. I agree that 79 percent apparent attenuation is as much as you could expect for Wyeast 1728 in an all-malt beer. The only thing you could have done would have been to substitute sugar for some of the malt. Actually, I think you will be quite happy with your F.G. of 1.020 for an 1.095 imperial stout. Big beers like this are supposed to have body and just a little residual sweetness. |