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Yeast Washing?

Discussion in 'Homebrewing' started by utahbeerdude, Aug 12, 2012.

  1. utahbeerdude

    utahbeerdude Savant (475) Utah May 2, 2006

    I have sitting in my fridge some WPL400 that was top cropped from a batch of Belgian wit. It has been sitting in the fridge for about 7 months. Certainly most of the yeast is not viable (dead), and so I would like to separate the living from the dead. Can this be done with yeast washing (about which I know practically nothing)? If so, can someone explain how to do this (or post a link to a decent link)? Or should I just go with some fresh yeast? Thanks!
  2. Homebrew42

    Homebrew42 Savant (435) New York Dec 20, 2006

    Yeast washing separates yeast from trub, it doesn't separate dead yeast from live yeast.
  3. mattbk

    mattbk Savant (425) New York Dec 12, 2011

    it is possible all of the yeast are dead. it is also possible any remaining live yeast will not make good beer. i would probably start over... but, if you wish to try it, i recommend the following procedure:

    if you do have any living, you may be able to passage them into fresh wort or a starter several times in order to grow up the living. take a decent portion of the old starter and add it to a new starter. i would advise a lot of shaking/stirring to give the yeast as much O2 as possible to promote growth. observe for signs of fermentation (bubbling airlock or krausen), it may be weak, but any activity means you have some living yeast. obviously, check the og and fg too (after 24 - 48 hours at a minimum), to determine if fermentation has occurred.

    repeat the process a few times, feeding a healthy portion of the previous starter to a new starter. with each successive passage you should see more fermentation activity in your starter. i would do this at least three times, or until the activity appears as a normal starter, or until you can achieve a good fg in a normal amount of time for a starter (ie 24 - 48 hours).

    good luck.
  4. utahbeerdude

    utahbeerdude Savant (475) Utah May 2, 2006

    Thanks for the responses. Given the info, I'll just go for some fresh yeast. I guess all that hard work why Wyeast and White Labs get the big bucks!
  5. Ilanko

    Ilanko Savant (255) New York Aug 3, 2012

    I have the same question on Harvested yeast fridge shelves life. my short term experience shows me that there is no bad yeast, i might put it in a different way "Dead yeast are not necessarily contaminated" and its obviously I am not making my living out of yeast products.
    Any yeast jar on my fridge gets in to the process of yeast erection :eek:
    The recycled yeast is kept on the fridge as long as needed, on brewing day I will move it out to room temperature for two hours, then give a 5 minute a nice shake. if i get to see some bubble or some foam, you are most likely have good potential healthy fermentation.
    Every brewing day i make sure I have an emergency dry yeast ready to cover for any bad experience.
    So far nothing went bad for me.
  6. VikeMan

    VikeMan Champion (855) Pennsylvania Jul 12, 2009 Verified

    If this were some rare/seasonal yeast strain that you just couldn't afford to lose, I'd try a stepped starter. (BTW, if you do this, pitch all of the yeast from each step into the next step, not just a 'healthy portion.') But starters with many steps get to be almost as expensive (and more of a pain in the ass) than just buying new yeast and doing a normal starter.