Author Topic: Trub volume between batches with different pitch rates  (Read 376 times)

Offline Joe_Beer

  • Cellarman
  • **
  • Posts: 81
Trub volume between batches with different pitch rates
« on: July 27, 2020, 01:06:39 AM »
So I brewed my first two batches this summer. The first batch, I used 11g of US-05 (one packet). The second batch called for TWO packets of yeast, so in went 22g.  When I cleaned out the second ferementer this weekend, it sure didn't look like twice the amount of trub in the bottom. It was really about the same amount as the 11g pitch. I'm curious why that is. How come 22g of yeast didn't produce twice the amount of trub?

Offline Bob357

  • Brewmaster
  • *****
  • Posts: 500
  • Consensus means nothing to me. I am who I am.
Re: Trub volume between batches with different pitch rates
« Reply #1 on: July 27, 2020, 07:00:08 AM »
Trub in the fermenter isn't only yeasts that have dropped out of suspension. It also contains proteins and hop debris transferred from the kettle, which can vary considerably depending on several factors. Probably the biggest factor is how well the proteins were allowed to settle out before transferring from the kettle. Generally speaking, higher gravity beers will have a proportionately larger amount of kettle trub, Lesser factors include protein content of malts, adjuncts and/or extracts.
Healthy yeasts will multiply in order to meet the demands of fermentation. The demands vary but, as a rule, higher gravity beers have a proportionately  greater demand. It's more complex than that, but a subject for another thread. Both yeasts and proteins will settle out and compact in the bottom of your fermenter given enough time. Lower temperatures will speed the process.

My guess would be that you got a much cleaner transfer of your second batch, and/or allowed the yeast and trub to settle out and compact more at the end of fermentation.
Beer is my bucket list,

Bob357
Fallon, NV

Offline ynotbrusum

  • Official Poobah of No Life.
  • *
  • Posts: 3725
Re: Trub volume between batches with different pitch rates
« Reply #2 on: July 27, 2020, 04:11:13 PM »
Bob's points are certainly valid as to the composition of the trub.  Even so, the yeast cells can only deplete the sugars available, so twice the pitched yeast does not mean twice the number of cells post fermentation, because the yeast have just the sugars available in the wort to metabolize and in theory, there would, therefore, be roughly the same amount of yeast resulting, if both batches of wort were similarly composed.
Hodge Garage Brewing: "Brew with a glad heart!"

Offline Joe_Beer

  • Cellarman
  • **
  • Posts: 81
Re: Trub volume between batches with different pitch rates
« Reply #3 on: July 27, 2020, 07:10:53 PM »
Bob's points are certainly valid as to the composition of the trub.  Even so, the yeast cells can only deplete the sugars available, so twice the pitched yeast does not mean twice the number of cells post fermentation, because the yeast have just the sugars available in the wort to metabolize and in theory, there would, therefore, be roughly the same amount of yeast resulting, if both batches of wort were similarly composed.

Bob357 and ynotbrusum - Thanks for the info. From what I recall, both transfers looked (subjectively) clear - bubbles started to form (hopefully co2) in the line about midway through so clear enough to see those I guess.  I did do the same closed transfer on both.  If I understand the sugars correctly, the OG and FG are representative of the sugars available correct? Both brews did have similar gravity (numbers below are straight off the Refractometer, so not wort corrected):

  • 1st) 14.9 - 8.4 Brix (1.065 - 1.037)
  • 2nd) 13.9 - 6.9 Brix (1.060 - 1.030)
I guess the next question I would have would be regarding using two packets of yeast (according to the kit directions on the second batch) when one may have sufficed anyhow but I can probably research that instead of beating another thread to death about pitch rates.

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 22911
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Trub volume between batches with different pitch rates
« Reply #4 on: July 27, 2020, 07:27:39 PM »
Bob's points are certainly valid as to the composition of the trub.  Even so, the yeast cells can only deplete the sugars available, so twice the pitched yeast does not mean twice the number of cells post fermentation, because the yeast have just the sugars available in the wort to metabolize and in theory, there would, therefore, be roughly the same amount of yeast resulting, if both batches of wort were similarly composed.

Bob357 and ynotbrusum - Thanks for the info. From what I recall, both transfers looked (subjectively) clear - bubbles started to form (hopefully co2) in the line about midway through so clear enough to see those I guess.  I did do the same closed transfer on both.  If I understand the sugars correctly, the OG and FG are representative of the sugars available correct? Both brews did have similar gravity (numbers below are straight off the Refractometer, so not wort corrected):

  • 1st) 14.9 - 8.4 Brix (1.065 - 1.037)
  • 2nd) 13.9 - 6.9 Brix (1.060 - 1.030)
I guess the next question I would have would be regarding using two packets of yeast (according to the kit directions on the second batch) when one may have sufficed anyhow but I can probably research that instead of beating another thread to death about pitch rates.

In general, I use 1 pack of dry yeast, no hydration, no aeration, for beers up to 1.065-70
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 Joe_Beer

  • Cellarman
  • **
  • Posts: 81
Re: Trub volume between batches with different pitch rates
« Reply #5 on: July 27, 2020, 08:06:27 PM »
In general, I use 1 pack of dry yeast, no hydration, no aeration, for beers up to 1.065-70

Interesting. You don't find it neccesary to "proof" (think that's what you mean by hydration) or introduce oxygen before pitching? I certainaly respect your experience and appreciate you sharing your perspective :D. It's just that this seems to runs a little contrary to stuff I've read. Like most things though, reailty often does dictate that the facts be tempered with reason so I guess I shouldn't be too surprised.

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 22911
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Trub volume between batches with different pitch rates
« Reply #6 on: July 27, 2020, 08:23:23 PM »
In general, I use 1 pack of dry yeast, no hydration, no aeration, for beers up to 1.065-70

Interesting. You don't find it neccesary to "proof" (think that's what you mean by hydration) or introduce oxygen before pitching? I certainaly respect your experience and appreciate you sharing your perspective :D. It's just that this seems to runs a little contrary to stuff I've read. Like most things though, reailty often does dictate that the facts be tempered with reason so I guess I shouldn't be too surprised.

The yeast companies say it's unnecessary and my experience agrees.  There are so many cells in a pack that rehydration isn't needed.  Aeration is so the yeast can use the O2 to produce sterols to keep ddell walls flexible for budding.  But when dry yeast is produced, it's stopped during the sterol growth phase, so it already has all the sterols it needs.  What you (we all) hear is outdated info.  But both Lallemand and Fermentis will tell you differently if you ask them.  Unfortunately, it's easier to just repeat incorrect, outdated info.
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: 3761
Trub volume between batches with different pitch rates
« Reply #7 on: July 27, 2020, 10:21:47 PM »
In general, I use 1 pack of dry yeast, no hydration, no aeration, for beers up to 1.065-70

Interesting. You don't find it neccesary to "proof" (think that's what you mean by hydration) or introduce oxygen before pitching? I certainaly respect your experience and appreciate you sharing your perspective :D. It's just that this seems to runs a little contrary to stuff I've read. Like most things though, reailty often does dictate that the facts be tempered with reason so I guess I shouldn't be too surprised.
According to Lallemand’s online calculator, the cutoff for one 11 gram pkg ends at 1.042 for 5.5 gal  using Bry-97.  Other yeasts and volumes could require differing amounts — I didn’t ck them all. More yeast is recommended for a higher gravity. My normal ~ 1.056 wort requires 14.57 grams. I usually pitch 14.5-15 grams. Here’s a link to their calculator: https://www.lallemandbrewing.com/en/united-states/brewers-corner/brewing-tools/pitching-rate-calculator/

Fermentis doesn’t give a direct account for gravity but gives a range of .5-.8 g per liter for Ale and .8-1.2 g per liter for Lager yeast. They leave it to the brewer to decide where to land in the range. My 5.5 gal in the fermenter ~ 21 liters. ...so 10.5 g - 16.8 grams for Ale and 16.8 - 25 grams for Lager. My 14.5-15 grams of an Ale yeast would fit in this range.

Most dry yeast mfr give both rehydration and direct pitch instructions.  Only Fermentis gives proofing instructions.  I only proof a repitch using their instructions.

...but even Fermentis’ direct pitch instructions don’t describe sprinkling it atop the wort. They recommend filling the fermenter partially, pitching the yeast as it’s progressively filled, then completely fill the fermenter. That’s what I do.

Both mfr say aeration is not required for first run yeast. However, if the yeast is harvested, each subsequent pitch must be aerated.

Sent from my iPad using Tapatalk
« Last Edit: July 28, 2020, 12:11:01 AM by BrewBama »
“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 BrewnWKopperKat

  • 1st Kit
  • *
  • Posts: 9
Re: Trub volume between batches with different pitch rates
« Reply #8 on: July 27, 2020, 10:56:23 PM »
Sprinkling on top of the wort appears to be a valid option (with emphasis on option) for US-05 (and probably many other Fermentis strains):
Quote
Direct pitching:

Pitch the yeast directly in the fermentation vessel on the surface of the wort at or above the fermentation temperature.
Progressively sprinkle the dry yeast into the wort ensuring the yeast covers all the surface of wort available to avoid clumps.

https://fermentis.com/en/fermentation-solutions/you-create-beer/safale-us-05/


Offline BrewBama

  • Official Poobah of No Life.
  • *
  • Posts: 3761
Trub volume between batches with different pitch rates
« Reply #9 on: July 27, 2020, 11:00:20 PM »


...from the page linked above: (I believe‘progressively’ would indicate as your filling vs after the fermenter is completely filled. The instructions go on to describe an ideal situation where the fermenter is partially filled)



...from the Fermentis Tips and Tricks pamphlet https://fermentis.com/wp-content/uploads/2019/10/Brochure_Tips_and_Tricks_BAT_BD.pdf: (this is how I pitch)




Sent from my iPad using Tapatalk
« Last Edit: July 27, 2020, 11:48:14 PM by BrewBama »
“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 Semper Sitientem

  • Cellarman
  • **
  • Posts: 42
Re: Trub volume between batches with different pitch rates
« Reply #10 on: July 27, 2020, 11:37:59 PM »
I began using the direct pitch method (Partially fill fermenter, add yeast, complete fill) several months ago and Found I’m getting  quicker starts than previously.
Confidunt in cervisia nobis

Offline BrewnWKopperKat

  • 1st Kit
  • *
  • Posts: 9
Re: Trub volume between batches with different pitch rates
« Reply #11 on: July 28, 2020, 12:10:01 AM »
...from the page linked above: (I believe‘progressively’ would indicate as your filling vs after the fermenter is completely filled. The instructions go on to describe an ideal situation where the fermenter is partially filled)
  I see your interpretation.  For larger (commercial?) fermenters, especially where time is a factor, this would be value in using this option.

I also know from my experiences that I can sprinkle the yeast on top of the wort and walk away.  The yeast settles quickly and goes to work in about a day.  FWIW, I'm not concerned about fast starts - I tend to brew / bottle on the weekends, so 12-14 days in the fermenter is generally the plan.
« Last Edit: July 28, 2020, 12:12:37 AM by BrewnWKopperKat »

Offline erockrph

  • Official Poobah of No Life.
  • *
  • Posts: 6520
  • Chepachet, RI
    • The Hop WHisperer
Re: Trub volume between batches with different pitch rates
« Reply #12 on: July 28, 2020, 12:52:17 AM »
...from the page linked above: (I believe‘progressively’ would indicate as your filling vs after the fermenter is completely filled. The instructions go on to describe an ideal situation where the fermenter is partially filled)
  I see your interpretation. For larger (commercial?) fermenters, especially where time is a factor, this would be value in using this option.

I also know from my experiences that I can sprinkle the yeast on top of the wort and walk away.  The yeast settles quickly and goes to work in about a day.  FWIW, I'm not concerned about fast starts - I tend to brew / bottle on the weekends, so 12-14 days in the fermenter is generally the plan.

To your point, I feel that "getting a fast start" is a primary priority for yeast labs, and that leads to some of the pitching, pitch rate, and temperature recommendations they make. I also have a "no rush" philosophy when brewing, and I'm less concerned with how rapidly fermentation starts up, and more concerned with the flavor of my finished beer. I tried rehydrating, but I find that the "sprinkle and walk away" method yields no noticible difference in flavor. With dry yeasts, I pitch either "about half" or 1 full packet of yeast for a 3 gallon batch, depending on yeast strain, gravity, and my previous experience. That's close enough for government work, AFAIC.
Eric B.

Finally got around to starting a homebrewing blog: The Hop Whisperer

Offline BrewBama

  • Official Poobah of No Life.
  • *
  • Posts: 3761
Trub volume between batches with different pitch rates
« Reply #13 on: July 28, 2020, 12:44:09 PM »
I think it’s great that there are so many paths to the end goal.

I certainly understand relaxed brewing. My processes are all designed with that in mind.  Using the mfr recommendation is just another way for me to relax.

Does the recommended qty matter?  Maybe. Maybe not. ...but I have experienced a difference in performance. 

Before, when one pkg of Bry-97 sprinkled on top and no nutrient was ‘good enough’, I’d get very long lag (I’ve seen 36 hrs), sluggish fermentation, and slow completion.

A pleasant byproduct of using the mfr recommendation, yeast nutrient, and the pitch method is a very predictable 14-18 hr start and complete fermentation in about a week as well as a beautifully clear, great tasting beer.

That predictability is very relaxing.

Sent from my iPad using Tapatalk
« Last Edit: July 28, 2020, 12:51:27 PM by BrewBama »
“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 goose

  • Brewmaster
  • *****
  • Posts: 830
Re: Trub volume between batches with different pitch rates
« Reply #14 on: July 28, 2020, 01:19:59 PM »
With dry yeasts, I have always used the "sprinkle and walk away" approach in a full fermenter but have been toying with the idea of pitching the yeast during the filling of the fermenter.   Ironically, this idea just popped into my head a few days ago before this thread started.  Full disclosure, I normally use liquid yeast and make starters for most of my beers, but liked the results that I got in my RIS with S-04 the last time I brewed it.

Just for grins, I am going to try pitching S-04 in a partially full fermenter when I brew my coffee porter next week.
Goose Steingass
Wooster, OH
Society of Akron Area Zymurgists (SAAZ)
Wayne County Brew Club
Mansfield Brew Club
BJCP Certified
AHA Governing Committee Member