Black Mould on a Vial

Discussion in 'Grain, Hops, Yeast & Water' started by Mrobson, Oct 9, 2019.

Help Support The Homebrew Forum UK by donating:

  1. Oct 9, 2019 #1

    Mrobson

    Mrobson

    Mrobson

    Well-Known Member

    Joined:
    Oct 5, 2017
    Messages:
    111
    Likes Received:
    23
    Location:
    NULL
    I’ve had a vial of yeast in the fridge for a few months and finally got round to using it. I boiled some light DME for the starter and when I opened the vial to pitch I noticed the lid was full of black mould and smelled of what I can only describe as wet wood. With nothing to loose I wiped away what I could from the top of vial, gave it a good shake with my starsan’ed finger over the top and pitched it anyway.

    2F3C1C7C-5418-4D0F-B57E-C133244DE2CC.jpeg 96399BAB-1C36-47AE-A46F-CDE09A622276.jpeg 019724A7-F3B7-4263-BDB7-08C50EAD0975.jpeg

    The starter seems very dark to me which is making me worried. I’ve got a cherry stout planned for the weekend, what’s the chances that the yeast is going to be usable or is it down to the beer gods? Would I be stupid to take the risk?

    Cheers

    Edit - it’s a proper Kveik strain, not an isolate
     
    Last edited: Oct 9, 2019
  2. Oct 9, 2019 #2

    the baron

    the baron

    the baron

    Landlord.

    Joined:
    Oct 13, 2013
    Messages:
    1,155
    Likes Received:
    372
    Location:
    castleford
    Not a yeast expert but doesn't look good to me I am sure the yeast masters will comment
     
  3. Oct 9, 2019 #3

    MyQul

    MyQul

    MyQul

    Chairman of the Bored Moderator

    Joined:
    Aug 7, 2013
    Messages:
    15,193
    Likes Received:
    5,665
    Location:
    Royal Hamlet of Peckham. London.
    I REALLY wouldnt be happy with that and deffo wouldn't pitch the starter into a batch
     
    foxbat likes this.
  4. Oct 9, 2019 #4

    the_quick

    the_quick

    the_quick

    Regular. Supporting Member

    Joined:
    Dec 7, 2018
    Messages:
    219
    Likes Received:
    70
    Location:
    Polegate, East Sussex
    Better be save than sorry and ditch that starter. You risk the whole batch to go bad.
     
  5. Oct 10, 2019 #5

    Mrobson

    Mrobson

    Mrobson

    Well-Known Member

    Joined:
    Oct 5, 2017
    Messages:
    111
    Likes Received:
    23
    Location:
    NULL
    Ye that’s what I was thinking too, going to let it ferment out anyway

    Cheers
     
  6. Oct 15, 2019 at 10:48 AM #6

    Mrobson

    Mrobson

    Mrobson

    Well-Known Member

    Joined:
    Oct 5, 2017
    Messages:
    111
    Likes Received:
    23
    Location:
    NULL
    I left this to ferment out and have the slurry drying in the spare room. I tasted the starter and couldn’t taste anything out of the ordinary, given it was only a few days old tho. Would a spell in the freezer kill whatever the black mould was or would making a batch with this yeast still be a gamble?
     
  7. Oct 15, 2019 at 11:23 AM #7

    BeerCat

    BeerCat

    BeerCat

    Landlord.

    Joined:
    May 6, 2015
    Messages:
    4,655
    Likes Received:
    1,331
    Location:
    East and West Grimblestbottom under the rye
    You can wash yeast with a chemical to kill the non yeasts. Forgotten the name.
     
  8. Oct 15, 2019 at 12:07 PM #8

    An Ankoù

    An Ankoù

    An Ankoù

    Landlord.

    Joined:
    Feb 2, 2019
    Messages:
    1,421
    Likes Received:
    620
    Location:
    Brittany, France
    Ditch it. It's more likely than not that it'll ruin your beer.
    I think BeerCat's referring to acid washing, which, I think, uses phosphoric acid to get rid of bacteria. Probably doesn't work with moulds.

    Have you got any bottles of the beer you originally used that yeast for? You could make a starter up from the sediment.
     
  9. Oct 16, 2019 at 11:00 PM #9

    BeerCat

    BeerCat

    BeerCat

    Landlord.

    Joined:
    May 6, 2015
    Messages:
    4,655
    Likes Received:
    1,331
    Location:
    East and West Grimblestbottom under the rye
    Yes your right been reading up on it. Interesting topic. I would dump the yeast and buy more.
     
  10. Oct 17, 2019 at 8:05 AM #10

    Mrobson

    Mrobson

    Mrobson

    Well-Known Member

    Joined:
    Oct 5, 2017
    Messages:
    111
    Likes Received:
    23
    Location:
    NULL
    From what I’ve read mould can be quite resilient.

    The yeast discussed in this topic in Espe, would anyone be up for a yeast swap? I’ve got both dried and slurry of the kveik strains I’ve currently got.
     

Share This Page