Author Topic: Very dark PurePitch yeast packs  (Read 279 times)

Offline gav

  • 1st Kit
  • *
  • Posts: 15
Very dark PurePitch yeast packs
« on: February 12, 2020, 08:06:30 PM »
Just opened 2 packs of WLP500 with a Best By date of 4/15/20 (mfg date 10/17/19, 86% viability per my calcs), and both liquid packs were med-dark brown. I'm used to seeing a creamy white or off/white yeast slurry, and I'm concerned that the yeast might be dead, or partially dead.
Just pitched a 2L starter with Light Pilsner DME, and the starter wort is brown. There was no funky smell when packs were opened and pitched, but no yeasty smell either.

I just got off the phone with WL, and they say this is normal, as they sometimes switch out their propagation wort from DME to grain-based and vice-versa. Seems a little weird to me, as I assumed labs separate yeast from propagation starter before release, just as many homebrewers do with water after harvesting.

I've heard from a local pro brewer that large yeast mfgrs sometimes dump bad batches on the Homebrew market - though WL seems to be pretty upstanding. They have dropped the mfg date on their packaging (very common these days in food-and-wine packaging) - really bugs me with packaged craft beers (don't get me started on coffee roast dates!) - but they are very transparent about the mfg (QC) date if you take the trouble to enter the printed Lot# on their yeastman.com website (QC link)
I'm going to wait to see if the starter takes off, but I have no reliable means to get a cell count for pitching if the starting viable cell count was off. WL said they stand by their product and offer a replacement guarantee if it is defective, but I hate to ruin a whole batch finding out.

Any thoughts?
Isn't beer the holy libation of sincerity? The potion that dispels all hypocrisy, any charade of fine manners? The drink that does nothing worse than incite one to urinate in all innocence, to gain weight in all frankness?
Milan Kundera

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 22466
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Very dark PurePitch yeast packs
« Reply #1 on: February 12, 2020, 08:10:33 PM »
You got the answer from White Labs.  What the brewer told you is not based on fact.
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 BrewBama

  • Official Poobah of No Life.
  • *
  • Posts: 3553
Re: Very dark PurePitch yeast packs
« Reply #2 on: February 12, 2020, 08:33:09 PM »
Did the starter perform well?


Sent from my iPhone using Tapatalk
“From man’s sweat and God’s love, beer came into the world.” — St. Arnold

Brewed in the Tennessee Valley. Rocket City — Huntsville AL

Offline ynotbrusum

  • Official Poobah of No Life.
  • *
  • Posts: 3622
Re: Very dark PurePitch yeast packs
« Reply #3 on: February 12, 2020, 09:57:42 PM »
I find it hard to believe that any yeast lab would "dump" defective product into the homebrew market.  I would believe that handling and shipping could render a yeast package unusable.
Hodge Garage Brewing: "Brew with a glad heart!"

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 22466
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Very dark PurePitch yeast packs
« Reply #4 on: February 12, 2020, 10:27:15 PM »
I find it hard to believe that any yeast lab would "dump" defective product into the homebrew market.  I would believe that handling and shipping could render a yeast package unusable.

I can tell you with 99.9% certainty that doesn't happen.  We get the same products that everyone else does.
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 hopfenundmalz

  • Global Moderator
  • I must live here
  • *****
  • Posts: 9830
  • Milford, MI
Re: Very dark PurePitch yeast packs
« Reply #5 on: February 13, 2020, 01:10:21 AM »
Define a bad batch of yeast.

Many smaller breweries will propagate from a pack or two if they have time. They have plenty of wort.
Jeff Rankert
AHA Lifetime Member
BJCP National
Ann Arbor Brewers Guild
Home-brewing, not just a hobby, it is a lifestyle!

Offline tommymorris

  • I spend way too much time on the AHA forum
  • ********
  • Posts: 2617
Re: Very dark PurePitch yeast packs
« Reply #6 on: February 13, 2020, 01:57:19 AM »
I've heard from a local pro brewer that large yeast mfgrs sometimes dump bad batches on the Homebrew market

Any thoughts?

No business would do this. They would ruin their reputation.

Offline gav

  • 1st Kit
  • *
  • Posts: 15
Re: Very dark PurePitch yeast packs
« Reply #7 on: February 13, 2020, 09:46:30 PM »
Reporting back. After 24 hrs (starter on a stir plate at 69 deg room temp, 2 packs of WLP500 in 2L of 1.036 wort), there is and was NO signs of fermentation. Gravity reading is still 1.036 one day later. This yeast is dead as a doornail.
I'm going to chuck it and go find myself some new yeast.

edit: After speaking with my LHBS, I'm going to let this sit in the fridge for 12 hrs, and then visually examine the volume of the yeast slurry after it settles out. According to the vendor, gravity does not need to drop for cell multiplication.
« Last Edit: February 13, 2020, 10:06:58 PM by gav »
Isn't beer the holy libation of sincerity? The potion that dispels all hypocrisy, any charade of fine manners? The drink that does nothing worse than incite one to urinate in all innocence, to gain weight in all frankness?
Milan Kundera

Offline gav

  • 1st Kit
  • *
  • Posts: 15
Re: Very dark PurePitch yeast packs
« Reply #8 on: February 14, 2020, 04:21:06 PM »
Final report Day 3. After 24 hrs in the refrigerator, there is no yeast cake in the bottom of the flask. Wort is a bit lighter after settling, but not clear. The very thin layer of yeast when viewed from the bottom is dark brown and much darker than the wort.
This lot of yeast is definitely not healthy, if not dead.
I've followed the same best practices for making a starter I've used successfully multiple brews. My first dud.

Anyone have an opinion on the statement "starter gravity does not need to fall in order for yeast cells to multiply"?

My understanding is that during replication in an aerobic environment, yeast converts O2 and sugar to CO2 and H2O, as opposed to converting sugar to CO2 and C2H5OH (ethanol) during anaerobic fermentation. Even if the starter activity was purely aerobic, it looks to me that sugar depletion (without alcohol creation) would still lower the gravity.

Isn't beer the holy libation of sincerity? The potion that dispels all hypocrisy, any charade of fine manners? The drink that does nothing worse than incite one to urinate in all innocence, to gain weight in all frankness?
Milan Kundera

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 22466
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Very dark PurePitch yeast packs
« Reply #9 on: February 14, 2020, 04:24:34 PM »
Final report Day 3. After 24 hrs in the refrigerator, there is no yeast cake in the bottom of the flask. Wort is a bit lighter after settling, but not clear. The very thin layer of yeast when viewed from the bottom is dark brown and much darker than the wort.
This lot of yeast is definitely not healthy, if not dead.
I've followed the same best practices for making a starter I've used successfully multiple brews. My first dud.

Anyone have an opinion on the statement "starter gravity does not need to fall in order for yeast cells to multiply"?

My understanding is that during replication in an aerobic environment, yeast converts O2 and sugar to CO2 and H2O, as opposed to converting sugar to CO2 and C2H5OH (ethanol) during anaerobic fermentation. Even if the starter activity was purely aerobic, it looks to me that sugar depletion (without alcohol creation) would still lower the gravity.

Of course the gravity will fall as the yeast multiplies
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 BrewBama

  • Official Poobah of No Life.
  • *
  • Posts: 3553
Re: Very dark PurePitch yeast packs
« Reply #10 on: February 14, 2020, 05:27:28 PM »
Sorry to hear about your negative experience.

This is an example of one of the reasons I went with dry yeast exclusively: Zero frustration. I experienced DOA liquid yeast one too many times.


Sent from my iPhone using Tapatalk
“From man’s sweat and God’s love, beer came into the world.” — St. Arnold

Brewed in the Tennessee Valley. Rocket City — Huntsville AL