OG Way lower than expected - how?

Discussion in 'General Brewing Discussions' started by Brewer #332145, Sep 29, 2020.

  1. WasteofLiam

    WasteofLiam New Member

    Joined:
    Sep 29, 2020
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    SoCal, USA
    Recently drafted a "Hazy DIPA" recipe in the recipe builder, with the following Fermentables:

    Method: Extract, full-volume for boil 60 minutes.
    Started with a volume around 8 gal., finished with probably 5.7 gal.

    1LB Flaked Oats(pre-gelatinized, steeped 30)
    1LB Flaked Wheat(pre-gelatinized, steeped 30)
    1LB Briess White Wheat Malt(Steeped 30)
    8oz Viking Wheat Malt(steeped 30)
    5LB Ultralight LME(60min)
    5LB Ultralight LME(late add, 15 min.)
    1LB Dextrose(Late add 15 min.)

    According to said recipe builder, if I attained a relatively low efficiency, I should be sitting around 1.075-1.080.

    Everything went well during the brew, nothing unexpected. Took my first OG reading when it was cooled properly, and I achieved a whopping......1.060? Look again and maybe even 1.059? This is literally 15-20 points lower than I anticipated, even when factoring in a 10-15% efficiency. Even with a theoretical 0% efficiency from steeping grains, the extract and dextrose alone should have gotten me to 1.070-1.075, correct? There was less than a 1/2 gallon surplus in my fermenter, but that amount shouldn't affect it by this much. I have no explanation that I can figure, help?

    I understand by doing some research that maybe I steeped the oats and wheat at the wrong temps and maybe for too long, but again, that doesn't really explain why I'm nearly 20% off my target OG. Frustrated and confused and would appreciate some guidance.

    Worth noting that I think the beer will still be fantastic, and the batch isn't ruined or anything like that. Mostly just confusion and wondering how I can accurately predict this in the future.
     
  2. Bubba Wade

    Bubba Wade Well-Known Member

    Joined:
    Sep 17, 2017
    Messages:
    616
    Likes Received:
    913
    Trophy Points:
    93
    Gender:
    Male
    Occupation:
    Controls & Instrumentation Engineer
    Location:
    Monroe, Louisiana
    Home Page:
    What was the wort temperature when you made the OG measurement? And what device did you use?
     
  3. WasteofLiam

    WasteofLiam New Member

    Joined:
    Sep 29, 2020
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    SoCal, USA
    Took a few readings at a few temperatures, but my final reading was around 65 deg. F. I used a triple-scale hydrometer, and afterwards made sure to do a reading in water at the same temp, hovered right at 1.000.
    I honestly was convinced that somehow I have to be reading wrong. Photo Sep 29, 9 34 40 AM.jpg
     
  4. Nola_Brew

    Nola_Brew Active Member

    Joined:
    Jul 9, 2015
    Messages:
    380
    Likes Received:
    246
    Trophy Points:
    43
    Location:
    Looziana
    What was the temp of the wort when checking gravity? if it's above 60 degrees then you will need to adjust for the temp difference. Most hydrometers are calibrated at 60 although I had one that was calibrated at 68.
    Also what size batch? 5 or 6 gal?
     
  5. BOB357

    BOB357 Well-Known Member

    Joined:
    Feb 3, 2018
    Messages:
    4,003
    Likes Received:
    7,333
    Trophy Points:
    113
    Location:
    Fallon, Nevada
    Most of the newer hydrometers are calibrated at 68 degrees F. It will almost always be listed on th ehydrometer.
     
    Josh Hughes and WasteofLiam like this.
  6. WasteofLiam

    WasteofLiam New Member

    Joined:
    Sep 29, 2020
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    SoCal, USA
    Wort was about 65 deg f. when read at 1.060. This is an older model that is calibrated at 60. When I built the recipe I anticipated a batch size of 5.5gal. Ended up with slightly above that in the fermenter, maybe 5.75gal.
     
  7. BOB357

    BOB357 Well-Known Member

    Joined:
    Feb 3, 2018
    Messages:
    4,003
    Likes Received:
    7,333
    Trophy Points:
    113
    Location:
    Fallon, Nevada
    If the recipe was for 5 gallons into the fermenter, you can attribute 10% to the extra 1/2 gallon. Other suspects are measurement error, including using markings on your kettle or fermenter unless you have verified their accuracy. Most factory markings are not correct. Steeping temperature can make a difference in conversion too. Also, your equipment profile is important. If you haven't entered one for your gear and dialed it in over a few batches, there's room for error there as well. You can pretty much take extract gravity expectations to the bank if you end up with the right volume. The recipe builder is quire accurate, but depends heavily on your inputs.
     
  8. WasteofLiam

    WasteofLiam New Member

    Joined:
    Sep 29, 2020
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    SoCal, USA
    I see what you mean. Recipe that I built was for 5.5 gal to fermenter, and I was ever so slightly above that. The incorrect markings & equipment profile thing does make sense to a degree. I have a very simple full-volume extract system 10 gal. kettle, burner, spoon, etc.
    Is it possible or rather, More likely that my reading is off or being affected somehow? Or is it more likely that something is off in the brewing process? Seems like my last several batches since I switched to full-volume have all come out lower than expected, but this one has the biggest error margin, and I am closest to my estimated volumes here than ever before.
     
  9. J A

    J A Well-Known Member

    Joined:
    Jan 19, 2016
    Messages:
    3,480
    Likes Received:
    2,699
    Trophy Points:
    113
    Location:
    Austin, Texas
    Make the recipe sharable and post the link. There'll be something in your settings that accounts for part of the difference and your volumes will account for the rest. Temperature on a hydro reading only account for a few points unless it's still extremely hot.
     
    BarbarianBrewer likes this.
  10. BOB357

    BOB357 Well-Known Member

    Joined:
    Feb 3, 2018
    Messages:
    4,003
    Likes Received:
    7,333
    Trophy Points:
    113
    Location:
    Fallon, Nevada
    I'd put my money on volumes. Boil off rate is always hard to pin down when you're using propane, but the entries for losses in your equipment profile are also important. Also suspect is that you refer to volumes as, "around 8 gallons", "probably 5.7 gallons" and "less than 1/2 gallon", that puts volumes on pretty shaky ground even if you have a good equipment profile. There is room for error when you're doing a partial boil and then topping up in the fermenter, but that goes away with full volume boils. Because you didn't have the problem before going to full volume boils, it make sense that volumes are the problem.
     
  11. Nola_Brew

    Nola_Brew Active Member

    Joined:
    Jul 9, 2015
    Messages:
    380
    Likes Received:
    246
    Trophy Points:
    43
    Location:
    Looziana
    I brew 5.5 gal batches (into fermenter) and i typically use 7.5 gal of water, depending on grain bill. I mash full volume (BIAB). My boil off is about .75 gal per hour.
    Check out priceless brewing and use his calculator to get your water amounts.
     
  12. FPMBomb

    FPMBomb Member

    Joined:
    Jul 11, 2017
    Messages:
    47
    Likes Received:
    39
    Trophy Points:
    18
    Gender:
    Male
    Occupation:
    Engineer
    Location:
    Phoenix, AZ
    It looks like you have a Diastatic Power problem. There is only 1.5 pounds of malted grains to convert an additional 2 pounds of adjuncts and if the steeping temp was low it may not have converted at all since you would have been in the protein rest temperature range. I know the Briess White Wheat has a DP of 160 but those Viking Malts are undermodified in comparison at only 65-70 DP. Personally I've found that any time I use a pound or so of flaked Oats I miss my expected OG by a few points and that's mashing them with Rahr or Briess 2 row for 60 min.
    This looks like recipe I created when I first started brewing (LME with flaked maize & 6-row)...really pushing extract to an extreme. It only took me that once to realize I wasn't saving anything and I went to BIAB without ever looking back.
     

Share This Page

arrow_white