Efficiency with Darker Specialty Malts

Discussion in 'Homebrewing' started by Hesscabob, Oct 16, 2015.

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  1. Hesscabob

    Hesscabob Initiate (0) Mar 16, 2014 Illinois

    Happy Friday everybody! On Monday, I brewed a planned 1.077 OG Oatmeal Porter. I used 75% which I thought was conservative as my last few batches (Saisons/Wheats) have reached an outrageous 90% efficiency. To my dismay, my brew landed on 1.059 OG with an efficiency of 58-60%.

    Grain bill:
    10.5 lb United Kingdom - Maris Otter Pale 38 3.75 75%
    2 lb Flaked Oats 33 2.2 14.3%
    0.5 lb American - Chocolate 29 350 3.6%
    0.5 lb American - Roasted Barley 33 300 3.6%
    0.25 lb American - Midnight Wheat Malt 33 550 1.8%
    0.25 lb United Kingdom - Black Patent 27 525 1.8%

    6 Gallons of H2O for Mash and 4 gallons of sparge. 8 gallons pre-boil. 5 gallons post-boil. (90 minute boil)

    I pinpointed my problem as possibly a bit from each of the below:
    1) Too little mash water.
    2) Grain absorbed more than expected.
    3) Should've drained grain bed more thoroughly before using all 4g of sparge water.
    4) Should I have simply swallowed my pride and lowered efficiency to 60% and boosted the grain bill to reach OG?

    My question is, how does everyone adjust their set-up/ mash water/ grain bill/ boil/ anything.... when using darker specialty malts?
     
    #1 Hesscabob, Oct 16, 2015
  2. wspscott

    wspscott Pooh-Bah (1,958) May 25, 2006 Kentucky
    Pooh-Bah

    When you say saisons and wheats, what gravity are you talking about? Do you regularly get 75% with a 1.075 gravity? It seems to be pretty well established that efficiency and OG move inversely, so higher gravity implies lower gravity and vice versa.

    TL;DR I don't thick it is a dark grain issue :slight_smile:
     
    #2 wspscott, Oct 16, 2015
  3. scottakelly

    scottakelly Maven (1,487) May 9, 2007 Ohio

    Agree its not a dark grain issue.

    I also think your beer sounds more like a Stout than a Porter to me, but I don't want to bring up that old debate.
     
    #3 scottakelly, Oct 16, 2015
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  4. CurtFromHershey

    CurtFromHershey Initiate (0) Oct 4, 2012 Minnesota

    Could be a mash pH issue. Are you using a calculator? Also, I've found that some published gravity point potentials on dark kilned malts are unreasonably high. I typically figure them for ~20-25 pts/lb/gal
     
    #4 CurtFromHershey, Oct 16, 2015
  5. JackHorzempa

    JackHorzempa Grand Pooh-Bah (3,375) Dec 15, 2005 Pennsylvania
    Society Pooh-Bah

    Linked below is a great presentation from Kai Troester entitled: “A Closer Look At Efficiency or How to make efficiency predictable.”

    In the presentation it has sage advice of: “It is not so much about the actual number. It is about being able to count on it.”

    Maybe there is some information in the presentation which will stimulate @Hesscabob on why he is obtaining varying performance wrt efficiency.

    One question I would have is concerning the milling of the grain: was the grain milled more coarsely for this Oatmeal Porter vs. previous batches?

    Cheers!

    http://braukaiser.com/download/Troester_NHC_2010_Efficiency.pdf
     
    #5 JackHorzempa, Oct 16, 2015
    Last edited: Oct 16, 2015
  6. CurtFromHershey

    CurtFromHershey Initiate (0) Oct 4, 2012 Minnesota

    Before I get called out on it, the "/gal" part is a mistake. Move along, nothing to see here folks.
     
    #6 CurtFromHershey, Oct 16, 2015
  7. Hesscabob

    Hesscabob Initiate (0) Mar 16, 2014 Illinois

     
    #7 Hesscabob, Oct 16, 2015
  8. telejunkie

    telejunkie Savant (1,107) Sep 14, 2007 Vermont

    That big of a jump seems like milling issues to me. So just want to make sure...I've had the mill gap move on me when one of the screw sets was loosened over time. So did you mill grains? If so, my first stop would be to check on the mill gap.
    25 pts/lb/gal seems about right for some of the heavier roasted grains, but like a chocolate malt or carafa, that should give up 30 pts or higher. Either way, they still are only like 10% of that grain bill...
     
    #8 telejunkie, Oct 16, 2015
  9. Hesscabob

    Hesscabob Initiate (0) Mar 16, 2014 Illinois

    What are your guys' typical efficiencies with Porters/Stouts? I cant remember ever crossing 70%...

    I mill at the same brew store I always do which is leaps and bounds better than the one I used prior.
     
    #9 Hesscabob, Oct 16, 2015
  10. Brew_Betty

    Brew_Betty Initiate (0) Jan 5, 2015 Wisconsin

    My 1.050-1.065 dark beers aren't significantly different in terms of efficiency than similar OG lighter beers.

    Above 1.070 efficiency is reduced by default.
     
    #10 Brew_Betty, Oct 16, 2015
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