Author Topic: Confessions of a Yeast Abuser  (Read 3024 times)

Offline brulosopher

  • Brewmaster
  • *****
  • Posts: 505
  • They who drink beer will think beer
    • Brülosophy
Re: Confessions of a Yeast Abuser
« Reply #15 on: April 07, 2016, 05:09:33 AM »
I like when the yeast abuses me

Offline brewinhard

  • Official Poobah of No Life.
  • *
  • Posts: 3272
Re: Confessions of a Yeast Abuser
« Reply #16 on: April 07, 2016, 01:19:55 PM »
I like when the yeast abuses me

Atta boy!  Now your thinking you dirty old man.

Offline zwiller

  • Brewmaster
  • *****
  • Posts: 570
Re: Confessions of a Yeast Abuser
« Reply #17 on: April 07, 2016, 03:12:30 PM »
It's probably the old punk rocker in me, but I really am put off by the anal mathematical website cell count calculator I need a microscope and a stir plate let me get my lab coat to brew beer approach to yeast starters and that is the primary reason I rebel against it. 
Sam
Sandusky, OH

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 20826
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Confessions of a Yeast Abuser
« Reply #18 on: April 07, 2016, 03:19:34 PM »
+1 Nope; you're not alone and my beers do not suffer. 

Denny, I guess I was wrong to assume you would always have a constant supply of fresh yeast since it is named after you...  Don't you have some sort QC thing to do regularly to make sure it's up to snuff?  ;D

Yeah, I brew beer!  I only get yeast once or twice a year...almost everything I use is out of date.  But since I almost always make a starter, it doesn't matter much.  This was kind of a "how far can I push it?" thing.

Are you buying in bulk or repitching?

I get shipments from Wyeast once or twice a year.  But I do a lot of repitching in between shipments.
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 denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 20826
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Confessions of a Yeast Abuser
« Reply #19 on: April 07, 2016, 03:20:52 PM »
+1 Nope; you're not alone and my beers do not suffer. 

Denny, I guess I was wrong to assume you would always have a constant supply of fresh yeast since it is named after you...  Don't you have some sort QC thing to do regularly to make sure it's up to snuff?  ;D

Yeah, I brew beer!  I only get yeast once or twice a year...almost everything I use is out of date.  But since I almost always make a starter, it doesn't matter much.  This was kind of a "how far can I push it?" thing.

The longest I've gone on old yeast successfully was about 10 months. I recently attempted a 27 month old vial I "found" in my fridge. It was propped up in a small starter @ 1.020 and pitched into a half gallon of cider. The cider had major THP. Definitely got some brett in there.

I've been able to resurrect a 3 1/2 year old pack of WY3522.  Why I did that, I don't know.
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 denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 20826
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Confessions of a Yeast Abuser
« Reply #20 on: April 07, 2016, 03:21:20 PM »
I like when the yeast abuses me

Atta boy!  Now your thinking you dirty old young man.
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 blair.streit

  • Brewmaster
  • *****
  • Posts: 522
Re: Confessions of a Yeast Abuser
« Reply #21 on: April 07, 2016, 03:25:56 PM »
I'm curious if you guys feel that you "compensate" in any way when you've abused your yeast? For example, if the yeast is old do you aerate more than you would otherwise or maybe throw in a little extra yeast nutrient?

I'm asking because I've struggled with vitality on repitching in a couple of previous batches (yeast pooped out early on the second batch). I've been attributing this to inadequate aeration in the first batch or possibly waiting too long to collect the yeast.

That said, pitching lager yeast in the mid 40's and fermenting at 50 may be too tough an environment to get away with yeast abuse. Thoughts?

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 20826
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Confessions of a Yeast Abuser
« Reply #22 on: April 07, 2016, 03:31:21 PM »
I'm curious if you guys feel that you "compensate" in any way when you've abused your yeast? For example, if the yeast is old do you aerate more than you would otherwise or maybe throw in a little extra yeast nutrient?

I'm asking because I've struggled with vitality on repitching in a couple of previous batches (yeast pooped out early on the second batch). I've been attributing this to inadequate aeration in the first batch or possibly waiting too long to collect the yeast.

That said, pitching lager yeast in the mid 40's and fermenting at 50 may be too tough an environment to get away with yeast abuse. Thoughts?

Nope, no compensation here...at least not in any consistent way.  And I abuse lager yeast just as you mention.

Let me say right here that this obviously isn't the best way to do things, and I don't recommend yeast abuse as a regular practice.  You have to be prepared for the fact that you may lose a batch of beer.  But I've found I can get away with it more often than not.
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 blair.streit

  • Brewmaster
  • *****
  • Posts: 522
Re: Confessions of a Yeast Abuser
« Reply #23 on: April 07, 2016, 04:08:44 PM »
Yeah the "punishment" I took was finishing at 1.024 instead of 1.019. Not the worst thing in the world. I just blended it with another batch and left plenty of yeast in suspension to lager for a bit longer. Not tragic.... 

Offline zwiller

  • Brewmaster
  • *****
  • Posts: 570
Re: Confessions of a Yeast Abuser
« Reply #24 on: April 07, 2016, 04:27:28 PM »
Back when I was fighting dry beers it was suggested to me that due to the longer growth phase, the yeast kick into overdrive and over-attenuate when underpitched...  I bought into it, did some starters, and no change.  I still think this hobby is way more forgiving than we make it seem.  Anyone ever have a mash that didn't convert?  Remember worrying about it?   ;D
Sam
Sandusky, OH

Offline 69franx

  • Official Poobah of No Life.
  • *
  • Posts: 3136
  • Bloatarian Brewing League
Re: Confessions of a Yeast Abuser
« Reply #25 on: April 08, 2016, 05:31:12 PM »
Back when I was fighting dry beers it was suggested to me that due to the longer growth phase, the yeast kick into overdrive and over-attenuate when underpitched...  I bought into it, did some starters, and no change.  I still think this hobby is way more forgiving than we make it seem.  Anyone ever have a mash that didn't convert?  Remember worrying about it?   ;D

Nice  8)
Frank L.
Fermenting:
Conditioning:
In keg: Ringler Pilsner (thanx Ron); House Clone (Skotrat style)
In the works:  BVIP, Czech Dark Lager

Offline euge

  • I must live here
  • **********
  • Posts: 8022
  • Ego ceruisam ad bibere cervisiam
Re: Confessions of a Yeast Abuser
« Reply #26 on: April 11, 2016, 09:33:49 PM »
I just repitched some lager-yeast but did it according to mrmalty. Pitching on a whole cake has not produced spectacular results for me.
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Laws are spider-webs, which catch the little flies, but cannot hold the big ones. -Anacharsis

Offline charles1968

  • Brewmaster
  • *****
  • Posts: 536
Re: Confessions of a Yeast Abuser
« Reply #27 on: April 12, 2016, 12:23:43 PM »
I don't buy the theory that pitching rate significantly affects flavour. The whole topic is full of pseudoscientific explanations, such as that underpitching causes stress (actually the opposite is true).

Anyway here's a 2008 paper suggesting that pitching rate makes very little difference to flavour, except for diacetyl level rising with high pitching rates (http://www.ncbi.nlm.nih.gov/pubmed/19018524).

Low pitching rate is completely fine in my experience. The only problem besides waiting a day or so longer is that there's higher risk of infection before the wort is colonized by yeast.

Abstract (my emphasis):
Quote
The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e. higher inoculum size). However, the impact of the pitching rate on crucial fermentation and beer quality parameters has never been assessed systematically. In this study, five pitching rates were applied to lab-scale fermentations to investigate its impact on the yeast physiology and beer quality. The fermentation rate increased significantly and the net yeast growth was lowered with increasing pitching rate, without affecting significantly the viability and the vitality of the yeast population. The build-up of unsaturated fatty acids in the initial phase of the fermentation was repressed when higher yeast concentrations were pitched. The expression levels of the genes HSP104 and HSP12 and the concentration of trehalose were higher with increased pitching rates, suggesting a moderate exposure to stress in case of higher cell concentrations. The influence of pitching rate on aroma compound production was rather limited, with the exception of total diacetyl levels, which strongly increased with the pitching rate. These results demonstrate that most aspects of the yeast physiology and flavour balance are not significantly or negatively affected when the pitching rate is changed. However, further research is needed to fully optimise the conditions for brewing beer with high cell density populations.


A more recent paper (http://onlinelibrary.wiley.com/doi/10.1002/jib.242/abstract)
Quote
With increasing numbers of cells introduced into the wort, the content of the esters and fusel alcohols increased, while the acetaldehyde concentration decreased. These changes affected the final quality of the beer.

Which contradicts the popular homebrewers' notion that underpitching makes yeast express esters more strongly because they're "stressed".

Obviously I've cherry picked these quotes to support my argument, but the best anyone can really say about pitching rate & perceptible flavour is that there's no clear scientific evidence of a relationship.
« Last Edit: April 12, 2016, 12:40:33 PM by charles1968 »

Offline zwiller

  • Brewmaster
  • *****
  • Posts: 570
Re: Confessions of a Yeast Abuser
« Reply #28 on: April 12, 2016, 02:52:59 PM »
8)
Sam
Sandusky, OH

Offline narvin

  • Brewmaster General
  • *******
  • Posts: 2286
  • Baltimore
Re: Confessions of a Yeast Abuser
« Reply #29 on: April 12, 2016, 04:01:50 PM »
I don't buy the theory that pitching rate significantly affects flavour. The whole topic is full of pseudoscientific explanations, such as that underpitching causes stress (actually the opposite is true).

Anyway here's a 2008 paper suggesting that pitching rate makes very little difference to flavour, except for diacetyl level rising with high pitching rates (http://www.ncbi.nlm.nih.gov/pubmed/19018524).

Low pitching rate is completely fine in my experience. The only problem besides waiting a day or so longer is that there's higher risk of infection before the wort is colonized by yeast.

Abstract (my emphasis):
Quote
The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e. higher inoculum size). However, the impact of the pitching rate on crucial fermentation and beer quality parameters has never been assessed systematically. In this study, five pitching rates were applied to lab-scale fermentations to investigate its impact on the yeast physiology and beer quality. The fermentation rate increased significantly and the net yeast growth was lowered with increasing pitching rate, without affecting significantly the viability and the vitality of the yeast population. The build-up of unsaturated fatty acids in the initial phase of the fermentation was repressed when higher yeast concentrations were pitched. The expression levels of the genes HSP104 and HSP12 and the concentration of trehalose were higher with increased pitching rates, suggesting a moderate exposure to stress in case of higher cell concentrations. The influence of pitching rate on aroma compound production was rather limited, with the exception of total diacetyl levels, which strongly increased with the pitching rate. These results demonstrate that most aspects of the yeast physiology and flavour balance are not significantly or negatively affected when the pitching rate is changed. However, further research is needed to fully optimise the conditions for brewing beer with high cell density populations.


A more recent paper (http://onlinelibrary.wiley.com/doi/10.1002/jib.242/abstract)
Quote
With increasing numbers of cells introduced into the wort, the content of the esters and fusel alcohols increased, while the acetaldehyde concentration decreased. These changes affected the final quality of the beer.

Which contradicts the popular homebrewers' notion that underpitching makes yeast express esters more strongly because they're "stressed".

Obviously I've cherry picked these quotes to support my argument, but the best anyone can really say about pitching rate & perceptible flavour is that there's no clear scientific evidence of a relationship.

One thing to remember is that a lot of these experiments are done with lager yeasts, because that's where the industry money is.  There are also differences I've noticed even across ale yeasts, so what's applicable to a pale ale might not be to a Belgian Saison.
Please do not reply if your[sic] an evil alien!
Thanks