Advice on poor attenuation.

Discussion in 'General Brewing Discussions' started by Missing Head, Jul 28, 2015.

  1. Missing Head

    Missing Head New Member

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    Hello all!

    So my buddy and I brewed up a Red Rye Ale a week ago and it has been bubbling away in our fermentor. However the gravity hasn't changed since day 2 and I am worried that it won't go any further!

    Recipe should have yielded 21l at 1.054-1.012, what we actually ended up with was 18l at 1.060 (we didn't count our sparge water properly).

    Day 2 I took a reading and the gravity had dropped to 1.030, just under 50% attenuation. But it's now stopped there. There are still bubbles coming out of the airlock even today so the yeast must be expelling something. But is that perhaps just their metabolic cycle acting as normal or is there still some minute fermentation occurring?

    So far I've stirred the wort back up and tried warming it up to 23c (our ferm temp is 20c) but to no avail.

    I've read that a large amount of cara/crystal can produce too much unfermentables, but our bill contains 65% golden promise, with the rest being cara/crystal/aromatic. Could this be the issue?

    Beer tastes good but I was hoping to hit that sweet 6% ABV with this one!
     
  2. jeffpn

    jeffpn Well-Known Member

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    What was your mash temp? Is your thermometer accurate?
     
  3. Ozarks Mountain Brew

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    if there is still foam on top and or still bubbling and you haven't met your ending gravity, then leave it and check it again when the bubbling has stopped for a day
     
  4. GernBlanston

    GernBlanston New Member

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    A few minor question for curiosity sake, with explanations to follow.

    1. Are you checking with a hydrometer or refractometer? Refractometers are inaccurate with increased alcohol levels.

    2. Did you pitch a big enough pitch of healthy yeast? Under pitching a big beer can cause it to stall out early.

    and,

    3. Why would you be checking gravity readings on day 2? Pitch, check for activity, and come back in two weeks.
     
  5. Nosybear

    Nosybear Well-Known Member

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    Another thing that stands out to me: 65% Golden Promise. That means you have a lot of other stuff in there that could have affected attenuation. With some yeasts, temperature swings will cause the yeast to flocculate out and stop fermentation. Problem there is once those beasties go to sleep, it's hard to wake them up. Also, your yeast may be done. If you mashed at a very high temp, say 156 degrees, you didn't make a lot of maltose for the yeast to eat. You state the beer tastes good - if it were underattenuated, it would be very sweet. The dextrines from a high mash temp aren't sweet, they just add mouth feel. So all in all, if the beer tastes good, I'd say you may actually be done due to some combination of highly flocculant yeast and high mash temps. Give it a few days to be sure - you don't want fermentation in your final packaging. If it's still at 1.030 in a few days, it's done.
     
  6. MrBIP

    MrBIP Active Member

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    Yep, wondering about mash temp and high amount of "others"....
    And, ya, let it sit. Give it two weeks and check.
    A recipe and more details might help pinpoint this.
     

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