Author Topic: Low SG for Dunkelweizen  (Read 1340 times)

Offline roguejim

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Low SG for Dunkelweizen
« on: May 15, 2011, 03:28:23 AM »
I brewed/batch sparged Jamil's Dunkelweizen recipe (all grain), with the addition of 1lb rice hulls to the mash.  When all of the wort was collected into the kettle, my SG was low by 9 points! (1.047 instead of 1.056) I checked the SG three times with the refractometer, and got the same reading.  I double checked everything that I can think of.  No possibility that I miss-weighed my grains.  Malt mill rollers hadn't drifted apart to lower the efficiency.  This is the only time I've used rice hulls, and I must say that the runoff from the mash tun was swift.But, this should be a positive, not a negative, right?  I'm stumped.  Any thoughts?

O'Dunkelweizen

A ProMash Recipe Report

Recipe Specifics
----------------

Batch Size (Gal):         7.00    Wort Size (Gal):    7.00
Total Grain (Lbs):       12.88
Anticipated OG:          1.056    Plato:             13.74
Anticipated SRM:          12.4
Anticipated IBU:          15.3
Brewhouse Efficiency:       80 %
Wort Boil Time:             60    Minutes

Pre-Boil Amounts
----------------

Evaporation Rate:       2.00    Gallons Per Hour
Pre-Boil Wort Size:    9.00    Gal
Pre-Boil Gravity:      1.043    SG          10.80  Plato


Grain/Extract/Sugar

   %     Amount     Name                          Origin        Potential SRM
-----------------------------------------------------------------------------
 54.4     7.00 lbs. Wheat Malt                    Germany        1.039      2
 23.3     3.00 lbs. Munich Malt                   Germany        1.037      8
 15.5     2.00 lbs. Pilsener                      Germany        1.038      2
  2.9     0.38 lbs. Crystal 40L                   America        1.034     40
  2.9     0.38 lbs. Special B Malt                Belgian        1.030    120
  1.0     0.13 lbs. Carafa Special II             Germany        1.030    430

Potential represented as SG per pound per gallon.


Hops

   Amount     Name                              Form    Alpha  IBU  Boil Time
-----------------------------------------------------------------------------
  1.20 oz.    Mt. Hood                          Pellet   4.40  15.3  60 min.


Extras

  Amount      Name                           Type      Time
--------------------------------------------------------------------------
  1.00 Lbs    Rice Hulls                     Other     60mins(mash)


Yeast
-----

  


Mash Schedule
-------------

Mash Type: Single Step

Grain Lbs:   12.88
Water Qts:   24.00 - Before Additional Infusions
Water Gal:    6.00 - Before Additional Infusions

Qts Water Per Lbs Grain: 1.86 - Before Additional Infusions

Saccharification Rest Temp : 152  Time:  60
Mash-out Rest Temp :           0  Time:   0
Sparge Temp :                  0  Time:   0


Total Mash Volume Gal: 7.03 - Dough-In Infusion Only

All temperature measurements are degrees Fahrenheit.



  

Offline Tony H.

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Re: Low SG for Dunkelweizen
« Reply #1 on: May 15, 2011, 01:55:41 PM »
I can't explain it, but it happened to me with my Summer Ale clone yesterday.  It was my first attempt at using wheat in an AG batch and my numbers were off about 10 points as well.

I hope someone chimes in and says it's due to the rice hulls or maybe the wheat itself.

I also noticed my water loss from mash tun (batch sparging) to brew kettle was significantly less.
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Offline Hokerer

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Re: Low SG for Dunkelweizen
« Reply #2 on: May 15, 2011, 02:46:41 PM »
It's often said that wheat malt can use "double crushing".  Lots of folks run any wheat through the mill first and then add the once crushed wheat to the rest of the grist and run all that through the mill.  Maybe your mill gap is set wide enough that a lot of the wheat is sneaking through?  Have you seen this kind of efficiency problem with other of your beers that have used a large percentage of wheat?
Joe

Offline thomasbarnes

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Re: Low SG for Dunkelweizen
« Reply #3 on: May 16, 2011, 12:52:02 AM »
Dumb question, but did you stir up the wort before you measured it? Sometimes you can get a density gradient which will give you a false reading.

Offline roguejim

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Re: Low SG for Dunkelweizen
« Reply #4 on: May 16, 2011, 02:08:08 AM »
It's often said that wheat malt can use "double crushing".  Lots of folks run any wheat through the mill first and then add the once crushed wheat to the rest of the grist and run all that through the mill.  Maybe your mill gap is set wide enough that a lot of the wheat is sneaking through?  Have you seen this kind of efficiency problem with other of your beers that have used a large percentage of wheat?

Interesting because I thought that wheat kernels were larger than regular 2-row barley kernels.  If I get 80% efficiency normally, why would it drop when using wheat, which is larger than the other kernels?  Wheat sneaking through, how?

Offline roguejim

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Re: Low SG for Dunkelweizen
« Reply #5 on: May 16, 2011, 02:09:29 AM »
Dumb question, but did you stir up the wort before you measured it? Sometimes you can get a density gradient which will give you a false reading.

I always stir.

Offline denny

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Re: Low SG for Dunkelweizen
« Reply #6 on: May 16, 2011, 03:40:09 PM »
Interesting because I thought that wheat kernels were larger than regular 2-row barley kernels.  If I get 80% efficiency normally, why would it drop when using wheat, which is larger than the other kernels?  Wheat sneaking through, how?

Because you're mistaken?  :)  Wheat kernels are smaller than barley, unless you somehow got "super wheat"!
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Offline Mark G

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Re: Low SG for Dunkelweizen
« Reply #7 on: May 16, 2011, 05:29:52 PM »
Did you boil off less volume than expected by any chance and end up with more than 7 gallons? Did you take a pre-boil gravity reading?
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Offline roguejim

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Re: Low SG for Dunkelweizen
« Reply #8 on: May 16, 2011, 06:35:22 PM »
Interesting because I thought that wheat kernels were larger than regular 2-row barley kernels.  If I get 80% efficiency normally, why would it drop when using wheat, which is larger than the other kernels?  Wheat sneaking through, how?

Because you're mistaken?  :)  Wheat kernels are smaller than barley, unless you somehow got "super wheat"!

Crap!  Just goes to show I never use wheat.  I think that solves the question.

To the other poster, my reading was pre-boil.  I made up for the hit with a longer boil.