High FG

Discussion in 'General Brewing Discussions' started by Nola_Brew, Oct 13, 2015.

  1. Nola_Brew

    Nola_Brew Active Member

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    I brewed two gallons of a APA on 9/26 using Denny's Fav. The recipe OG is 1.054 and FG was supposed to be 1.011. I bottled today, checked the FG and it was 1.020. Post boil OG was 1.053.

    What would cause the FG to be that high and off? Could it be bad yeast? I ordered the yeast and it arrived swollen and out-dated (April 2015). I made a starter and pitched into two 1 gallon carboys. I only checked the FG on one carboy but now that i think about it should have checked both.

    I did sample the beer and it taste good. I also checked the hydrometer in plain tap water and it was 1.000.

    Any reasons why this would have happened?
     
  2. Ozarks Mountain Brew

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    the 1020 curse, its an unknown phenomena, too many reasons to speculate, but the bottom line is you didn't get a good attenuation from the yeast, either it flocked too early or stalled for any of a number of reasons, stir the yeast up and let it sit
     
  3. Tar and Feather'em

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    Sounds like yeast trouble if it was as you describe but it could also be you didn't convert fully during the mash. What was your method? Temp and time on the mash?
     
  4. Nola_Brew

    Nola_Brew Active Member

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    My process: BIAB / 75 min boil / 60 min mash/ 10 min mash out
    My post boil OG was 1.053. Efficiency was in the mid 70's.
    I think it has to do with the yeast.

    Probably should have done what Ozark said but by the time I checked back on the forum I had already bottled. Heading out of town for three days and last night was the only time I had available to bottle.
     
  5. Tar and Feather'em

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    Yeah me too on the yeast but I have had high final gravity with mashing BIAB for 60 also. I have found I have to mash 75 to 90 mins to fully convert.

    Try doing an iodine test at 60 to check, that's what I started doing.
     
  6. Nola_Brew

    Nola_Brew Active Member

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    Guess I'll have to start doing an iodine test. Never had an issue before but I've only recently started checking my gravity.
    Thinking also of increasing boil time to 75 min but then I've been reading where most times a 30 min boil is sufficient for conversion.
    For now, I'll stick with 60-75 min boils although it would be nice to cut down on my 4.5 hr brew days.
    I harvested the Denny's yeast and will be using it this weekend in two batches. Hope all is good as I have no chance to make it to the HBS which is an hour away.
     
  7. Nosybear

    Nosybear Well-Known Member

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    I checked the attenuation on the yeast, mid-70% range. You should have gotten 1.013 or 1.014. There's a missing variable in the discussion so far, or I've missed it: What was your mash temperature? Since you state the beer tastes good - not cloyingly sweet - I'm assuming you got full attenuation for the wort you made, that your mash temp was either intentionally or accidentally high. If this is the case, you'd have gotten a lot of dextrines, short-chain starches that increase the body of the beer but are flavorless and unfermentable, leading to a high final gravity. But there is a check you still can do: If your yeast really didn't finish the job, your bottles will be very highly carbonated, in fact, if there is six points too much sugar in there, you may get bottle bombs. Once you open a bottle and it's way overcarbonated, you can assume unfermented sugars. If it's normal, you likely mashed at too high a temperature.

    Boil time has nothing to do with attenuation, by the way. I use a default 90 minute boil to get some kettle caramelization but for most malts, 60 minutes is adequate. I wouldn't go less because of the potential for off-flavors, most notably DMS. You may be referring to mash time, in which case, 30 minutes MAY be enough. I stick with 60 to be sure.
     
  8. Ozarks Mountain Brew

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    one thing to note that conversion has nothing to do with how much sugar content you get into your wort, you can be converted in 30 minutes but may only get 50% of sugar off the grain, when you mash longer it allows more sugar out of the gain by softening the husk more and allowing for better Lautering
     
  9. Nola_Brew

    Nola_Brew Active Member

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    Mash temp was 154 for 60 minutes with a 10 min mash out at 168. Boil time was 75 min.
    I checked the bottles last night and so far no bottle bombs. I'll crack one open over the weekend to check.
    My pre-boil was around 1.036 and post boil gravity was 1.054. The numbers may not be exact as my ppwk is at home.

    This brew was fermented in two 1 gallon carboys. One carboy had a little less then a gallon. I pitched a little less yeast in that one and something wasn't right with that particular carboy. There were some surface bubbles in that one and the krausen was not as big as the other carboy. So it's possible I didn't pitch enough yeast in that one but it was only slightly less then the full carboy.

    Also, the yeast I used was Denny's favorite and it was ordered online. Came in slightly swollen and with a date of April 2015. I made a 1.5 liter starter but it never formed any krausen. I also used a foaming agent so I've been told that may be the reason why there was no krausen. I was concerned the yeast wasn't any good but the first carboy fermented nicely.

    I did harvest 3.5 pint jars of yeast from this batch. It was actually about 1 full pint and a half pint from each carboy. I have each jar marked so I know which came from which carboy.

    I will be using the harvested yeast this weekend in two batches. Think I will use the yeast from the good carboy and save the other for another batch in a few weeks.
     

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