Author Topic: Regarding yeast starters...  (Read 1988 times)

Offline tom

  • Senior Brewmaster
  • ******
  • Posts: 1110
  • Denver, CO
    • View Profile
Re: Regarding yeast starters...
« Reply #15 on: June 01, 2011, 09:35:22 PM »
I noticed the mention of pouring off the spent wort (its not really beer due to the amount of aeration I provide) from the sedimented yeast.  I find that pouring doesn't work well.  I siphon off the spent wort after the yeast has sedimented from a crash cooling.  I can't really get all the wort off the yeast, but I get a lot off.  To rouse the yeast, I add a slug of the freshly chilled wort from my batch into the starter flask and put it back on the stirrer.  That is a happy bunch of yeast when its added to the rest of the wort in an hour or so.
Brilliant!  How do you do your little mini-siphon?  Maybe a sanitized "baster" or "thief" would work?
Brew on

Offline mabrungard

  • Brewmaster General
  • *******
  • Posts: 2063
  • Water matters!
    • View Profile
    • Bru'n Water
Re: Regarding yeast starters...
« Reply #16 on: June 02, 2011, 07:01:29 AM »
Just a length of typical 1/4 or 3/8" ID tubing, sanitized and inserted into the spent wort above the yeast cake.  Set the flask on the side of the sink and have the free end of the tubing extend into the sink.  A standard application of oral vacuum gets the flow started.  Since the spent wort is just going down the sink, the worries with contamination due to starting the siphon by mouth are non-existent as long as you keep the flow from back washing. 
Martin B
Carmel, IN

BJCP National
Foam Blowers of Indiana (FBI)

Brewing Water Information at:
https://sites.google.com/site/brunwater/

Like Bru'n Water on Facebook
https://www.facebook.com/Brun-Water-464551136933908/?ref=bookmarks

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 18227
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Regarding yeast starters...
« Reply #17 on: June 02, 2011, 07:54:14 AM »
My last several batches have had pretty long lag times.  I don't know if it was my allowing the starter to warm for a few hours before pitching or the hydrometer sample full of fresh wort I added to the starter (and put on the stir plate) but, my most recent batch was pitched late Sunday night and come Monday morning I already had blowoff.  Yeast seemed much happier.

Do what works, but make sure you're assessing the results correctly.  I did the exact opposite of you last weekend....took my yeast directly out of the fridge, decanted and pitched.  I had fermentation starting in 3 hours.  So, maybe your results are due to the actions you took and maybe they're due to something else.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

Offline bluesman

  • Global Moderator
  • I must live here
  • *****
  • Posts: 8822
  • Delaware
    • View Profile
Re: Regarding yeast starters...
« Reply #18 on: June 02, 2011, 08:03:41 AM »
Typically, I'll prepare a starter to 1.020-1.1030 and let it ferment out then crash cool. On brewday I'll remove the chilled starter from the refrigerator and allow it to warm up for a couple of hours then decant the beer and add some fresh starter wort to wake up the yeast cells in an effort to make them active and ready for the battle ahead. I usually allow the fresh starter to sit for an hour or two prior to pitching.
Ron Price

Offline Mark G

  • Brewmaster
  • *****
  • Posts: 898
  • Huntley, IL
    • View Profile
Re: Regarding yeast starters...
« Reply #19 on: June 02, 2011, 09:39:57 AM »
I used to chill, decant, then let the starter come up to the wort temp before pitching. A couple months back though, Denny mentioned just pitching it cold, so I've been trying that method since. There has been no noticeable difference in lag time, attenuation, flavor, etc. due to yeast performance. It's just my experience, and there's nothing wrong with letting it warm up, or adding more wort, etc., but I find pitching cold to be far more... pragmatic...
Mark Gres

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 18227
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Regarding yeast starters...
« Reply #20 on: June 02, 2011, 10:30:13 AM »
I used to chill, decant, then let the starter come up to the wort temp before pitching. A couple months back though, Denny mentioned just pitching it cold, so I've been trying that method since. There has been no noticeable difference in lag time, attenuation, flavor, etc. due to yeast performance. It's just my experience, and there's nothing wrong with letting it warm up, or adding more wort, etc., but I find pitching cold to be far more... pragmatic...

Gold Star!

Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

Offline SpanishCastleAle

  • Brewer
  • ****
  • Posts: 272
    • View Profile
Re: Regarding yeast starters...
« Reply #21 on: June 02, 2011, 11:40:54 AM »
I've been pitching cold for a while now and IME, if anything they take off quicker.

There was a question on cold-pitching in the Danstar FAQ and Dr. Clayton Cone said he wasn't sure why it worked so well but he hypothesized that it may have to do with glycogen/trehalose reserves.  When you hydrate dry yeast in warm water (the best way to hydrate dry yeast) you need to pitch it relatively quickly because if you don't the yeast start using their built-up glycogen/trehalose reserves.  He thought that perhaps letting yeast warm up prior to pitching had a similar effect; i.e. the yeast starts to use up it's internal reserves until pitched into nutrient/O2/sugar rich wort.

Offline narvin

  • Brewmaster General
  • *******
  • Posts: 2224
  • Baltimore
    • View Profile
Re: Regarding yeast starters...
« Reply #22 on: June 02, 2011, 11:54:04 AM »
Just a length of typical 1/4 or 3/8" ID tubing, sanitized and inserted into the spent wort above the yeast cake.  Set the flask on the side of the sink and have the free end of the tubing extend into the sink.  A standard application of oral vacuum gets the flow started.  Since the spent wort is just going down the sink, the worries with contamination due to starting the siphon by mouth are non-existent as long as you keep the flow from back washing.  

This is exactly what I do.  I also will toss the hydrometer sample in after to help stir up the yeast (making sure the hydrometer and cylinder is sanitized before collecting wort).
Please do not reply if your[sic] an evil alien!
Thanks

Offline Slowbrew

  • Brewmaster General
  • *******
  • Posts: 2294
  • The Slowly Losing IT Brewery in Urbandale, IA
    • View Profile
Re: Regarding yeast starters...
« Reply #23 on: June 02, 2011, 12:01:41 PM »
I decant or siphon off the extra wort from the starter.  Then run in some of the new wort I just boiled and chilled so I can swill it around to loosen up the yeast on the bottom.  After I finish transferring the wort to the primary I pitch the yeast.  Never had any issues.

Paul
Where the heck are we going?  And what's with this hand basket?

Offline tschmidlin

  • I must live here
  • **********
  • Posts: 8198
  • Redmond, WA
    • View Profile
Re: Regarding yeast starters...
« Reply #24 on: June 02, 2011, 12:59:19 PM »
I've been pitching cold for a while now and IME, if anything they take off quicker.

There was a question on cold-pitching in the Danstar FAQ and Dr. Clayton Cone said he wasn't sure why it worked so well but he hypothesized that it may have to do with glycogen/trehalose reserves.  When you hydrate dry yeast in warm water (the best way to hydrate dry yeast) you need to pitch it relatively quickly because if you don't the yeast start using their built-up glycogen/trehalose reserves.  He thought that perhaps letting yeast warm up prior to pitching had a similar effect; i.e. the yeast starts to use up it's internal reserves until pitched into nutrient/O2/sugar rich wort.
They will mostly "consume" their trehalose reserves within 5 minutes of coming to room temperature, but I don't believe that has anything to do with it.  They make trehalose when it's cold because it is a cryoprotectant and they are anticipating the temperature dropping further.  It also plays a role in dessication and ethanol tolerance.  Trehalose levels will drop because it is hydrolyzed to glucose, but we don't know that that glucose is all consumed or if the excess is converted to glycogen for a while before the cell begins consuming it.  Consuming the glycogen reserves seems like a more proximal answer to me.  I'd love to get a grant to test this at length with a trehalose deficient mutant . . .
Tom Schmidlin