Happy HolidaySs Giveaway - Winners Re-Re-Drawn - 24 hours to Claim!

Get your HBT Growlers, Shirts and Membership before the Rush!


Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > Attentuation question...
Reply
 
LinkBack Thread Tools
Old 10-13-2012, 06:32 AM   #1
mclamb6
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2012
Location: Phoenix, Arizona
Posts: 137
Liked 3 Times on 2 Posts

Default Attentuation question...

I've got an oatmeal stout in primary (5 gallon batch) with the following grain bill:

6.5 lbs Marris Otter
1.75 lbs 2 row
.5 lbs medium crystal (C60)
.75 lbs roasted barley
.75 lbs chocolate malt
.25 lbs dark crystal
1.75 lbs flaked oats
.5 lbs DME (left over extract from the starter)

Using WLP002 with a starter (probably slightly underpitched)
Oxygenation = vigorous shaking of fermenter before pitching

Mashed at 151-152 for 60 minutes

OG was 1.070.

According to BeerTools, FG is supposed to be around 1.017. After almost two weeks, gravity is 1.024 (fermenting at 68-70 degrees).

With the amount of unfermentables that I have, can I expect the beer to drop the additional 7 points or will I end up finishing a bit higher? It's dropped about 6 points since Wednesday. Am I just being impatient?

__________________
mclamb6 is offline
 
Reply With Quote Quick reply to this message
Old 10-13-2012, 02:11 PM   #2
duboman
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2011
Location: Glenview, IL
Posts: 6,334
Liked 502 Times on 464 Posts
Likes Given: 226

Default

Rouse the yeast and see if it will go lower over then next few days

Are you sure your thermometer is calibrated? Many aren't and you may have mashed warmer than you think.

__________________
Nothing Left to do but smile and drink beer.....

The Commune Brewing Company-Perfecting the "art" of beer since 2010
duboman is offline
 
Reply With Quote Quick reply to this message
Old 10-13-2012, 03:32 PM   #3
mclamb6
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2012
Location: Phoenix, Arizona
Posts: 137
Liked 3 Times on 2 Posts

Default

It's a digital, instant read thermometer. I certainly haven't noticed that it is off with any other batch. My OG was actually higher than anticipated, so I don't see how I missed my mash temp. Not to mention that I would have had to really misread the strike water temp to overshoot the mash temp very much.

__________________
mclamb6 is offline
 
Reply With Quote Quick reply to this message
Old 10-13-2012, 03:55 PM   #4
Stauffbier
HBT_SUPPORTER.png
Feedback Score: 1 reviews
 
Stauffbier's Avatar
Recipes 
 
Join Date: Nov 2011
Location: El Paso, TX
Posts: 5,115
Liked 1020 Times on 625 Posts
Likes Given: 2707

Default

WLP002 tends to drop like a rock. Gently rouse it and bump the temp up a degree or two. If you're still at 1.024 a week later, it's likely finished. Instant read digitals can indeed be off. Since 152F is mid range, if you were off by 2 or 3 degrees and actually mashed at 154F-155F you might note the difference in the amount of unfermentables.

__________________
Bier war sein letztes wort dann trugen ihn die Englein fort...

Stauffbier is offline
 
Reply With Quote Quick reply to this message
Old 10-13-2012, 07:14 PM   #5
duboman
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2011
Location: Glenview, IL
Posts: 6,334
Liked 502 Times on 464 Posts
Likes Given: 226

Default

Quote:
Originally Posted by mclamb6
It's a digital, instant read thermometer. I certainly haven't noticed that it is off with any other batch. My OG was actually higher than anticipated, so I don't see how I missed my mash temp. Not to mention that I would have had to really misread the strike water temp to overshoot the mash temp very much.
Mash temps will not effect the OG but the FG. High mash temps promote a less fermentable wort and fuller bodies beer or higher FG. Lower temps will promote a more fermentable wort and lower FG and less body.

As Stauffbeir mentioned a +\- 2 degree difference can be the difference of a few gravity points
__________________
Nothing Left to do but smile and drink beer.....

The Commune Brewing Company-Perfecting the "art" of beer since 2010
duboman is offline
 
Reply With Quote Quick reply to this message
Old 10-13-2012, 07:21 PM   #6
Golddiggie
HBT_SUPPORTER.png
Feedback Score: 1 reviews
 
Golddiggie's Avatar
Recipes 
 
Join Date: Dec 2010
Location: Between here and there, and everywhere
Posts: 12,058
Liked 480 Times on 421 Posts
Likes Given: 266

Default

You're at ~66% attenuation, which is within the range posted by White Labs for that strain (63-70%). As already mentioned, if it doesn't change in a week, or so, then chances are the yeast has done all it can. Since it's dropped some more since the middle of the week, it could still be fermenting. Give it the time it needs to finish.

At that OG, I'd give the brew [at least] 3-4 weeks in primary before thinking about going to bottle/keg with it.

__________________
Hopping Tango Brewery

跟猴子比丟屎 ・ Gun HOE-tze bee DIO-se

On Tap: Caramel Ale, Mocha Porter II, MO SMaSH IPA
Waiting/Carbonating: 12.5% Wee Honey II, 8.9% Old Ale, English Brown Ale, Lickah ESB, Mocha Porter II
Fermenting
K1:
K2: Epic mead
K3: TripSix
On Deck: Caramel Ale
Aging:mead
Mead [bottled]:Oaked Wildflower Traditional, Mocha Madness, Blackberry Melomel, maple wine
Golddiggie is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
low attentuation from pitching yeast slurry? laserghost Fermentation & Yeast 5 07-02-2012 12:08 AM
serious attentuation hoppymonkey Fermentation & Yeast 5 04-26-2010 10:10 PM
Attentuation batfishdog37 General Techniques 3 03-06-2009 03:24 PM
attentuation ? clemson55 Beginners Beer Brewing Forum 1 02-20-2008 03:10 PM
carbing and attentuation question proton General Techniques 6 05-04-2007 10:29 PM



Newest Threads

LATEST SPONSOR DEALS