First brew back - poor efficiency and off flavours - Where to start?

Discussion in 'All Grain Brewing' started by SBOB, 12/1/18.

 

  1. SBOB

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    Posted 12/1/18
    Due to selling a house, moving, cluttered garage etc etc, last week was my first brew day in ~10mths

    Did a recipe i'd done before but seemed to miss my numbers on both brews i did up (under expected SG by +0.02 on one recipe and 0.01 on another, both with an 1.050 expected SG)
    No-chilled it.

    Revived some frozen yeast ok (1056)

    But a week after pitching, seems to have an off flavour. Not sure what, maybe a bit of a fusel alcohol, but im not the best at describing off flavours and im just going from a hydrometer sample.

    So im trying to work out what might be the most likely cause

    • Grain - same stuff has been sitting in containers/sack since last brew, so most is going to be 18mths+ old
    • Hops - been in the freezer, but would be 18mths+ old
    • Yeast - been in the freezer, using Yob's popular freezing technique. never had an issue reviving any previously. This one was 18mths in the freezer
    • Technique - new grain mill (Mash master from the bulk buy) and lauter helix (weal supplied) but the rest is same as before.

    Anyone have any tips/pointers on where to start.
    Grain too old, and should just dump it all and start again?
    Yeast
    Sanitation (gave everything a re-clean pre brew)


    Thanks for any tips.. been a while since i've had to dump a batch
     
    Last edited: 12/1/18
  2. manticle

    Standing up for the Aussie Bottler

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    Posted 12/1/18
    Fusels I would relate to poor yeast health or hot temp. I’m assuming you’ve got temp down pat so maybe yeast was just cactus.
     
  3. SBOB

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    Posted 12/1/18
    yeah, seems to be a yeast related off flavour

    though im lost why mash efficiency and boil off rate are different after moving (no change in geography/altitude)

    might grab some us05 for the second cube and give it a shot
     
  4. Brewno Marz

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    Posted 12/1/18
    0.02 off on OG is huge. That means you got 1.030 on a target OG of 1.050! Think positive...it'll be low carb!
     
  5. MHB

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    Posted 12/1/18
    As is often the case in brewing it could be a bit of A, some B and a touch of C
    Malt usually has a shelf life of around 18 months (from manufacture), yours could well be older, as time passes enzymes die and yield will drop, effects of Oxidisation, Lipidase will become more obvious...
    Frozen yeast isn't forever, well not at home, yeast banks freeze in liquid Nitrogen. At relatively warm storage (say above -10oC) yeast will still die slowly, will still mutate and deplete its reserve (loose vitality) all be it slowly. You could have a smaller than expected population, of less healthy yeast - especially if during moving the yeast got a bit warmer, stored yeast likes as cold and stable as possible.
    Hops, again they have a shelf life even vacuumed and frozen, no matter how careful you are they don't improve with age.

    A new mill, well have a good look at what is coming out, use a sieve to help evaluate your crush, not too much flour nor too many unopened/uncrushed corns.
    You haven't given any details on changes to you evaporation rate, clean the jet on your burner and all the little holes, look for drafts that can cause cooling, look at how well the steam is getting away from the kettle. All the little things that add up to a successful and repeatable brew day.
    Mark
     
    Last edited: 12/1/18
  6. SBOB

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    Posted 13/1/18
    thanks for the feedback

    Think it might be time to just scrap the malts and yeast and start again fresh

    The new mill is one of the mill master w/ fluted rollers and the crush seemed ok on a ~0.9mm gap

    Evaporation rate did seem less, with only change being now brewing in garage v outside previously. Electric setup, so amount of energy going in shouldnt have changed.
     
  7. gezzanet

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    Posted 15/1/18
    Been running a new mill from the bulk buy with 0.9mm gap for Biab as well and works fine.
    Been using up some old malts of about that vintage ( maybe older). Still crunchy in mouth prior to milling and doesn’t have that stale biscuit softness. Prob not the best but ok for Xmas swill.
    Last time I had a bad batch my yeast wasn’t looked after that well
    I’d prob look at yeast.
    Did you really get 1.03 rather than 1.05?
    Maybe busted thermometer ?
     

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