Author Topic: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool  (Read 6946 times)

Offline Waldner

  • BeerSmith Brewer
  • ***
  • Posts: 36
When using the yeast starter tool to determine the size of the starter needed, are you supposed to take the percentage generated in the "Yeast Viability" box based on the package date of your yeast and calculate the number of viable cells in your package (i.e. 1,000,000,000 x .75 = 750,000,000) and put this number in the "Starter Pack Cell Count" field to get the correct starter size needed or does BeerSmith do this automatically?

Also, the label reads "billion" so would you still type in 750,000,000 even though it's actually only millions?

I'm just a little confused as to whether or not I'm using this tool correctly.

Thanks and cheers!

Offline bperetto

  • BeerSmith Brewer
  • ***
  • Posts: 26
  • KotMF
    • Twin Hills Brewery
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #1 on: October 30, 2012, 01:59:14 PM »
I have a somewhat similar question.  I'm just wondering how viability is calculated between a tube and a smack pack.  The latter obviously being like a mini starter. Wouldn't a fully expanded smack pack that's, say, 3 months old have more viable cells than a tube that's 3 month old? The cells that are viable are likely to reproduce in the smack pack and increase the overall count of viable cells.

Right now, they both types of products have around 81% viability.

I'm not really worried about my pitch rate like some of you.  Those absurd pitch rates generated by mr malty are based on professional production where they try to push beer out in a hurry.  I'm just more curious than anything. My beer is just fine and from what I've had of Zainey's commercial offerings, better than his.

Bryan "Sir Vorlauf" Peretto
Celebrating 10 years of the fermenting arts.

www.KotMF.com - Knights of the Mashing Fork

Offline Waldner

  • BeerSmith Brewer
  • ***
  • Posts: 36
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #2 on: November 02, 2012, 07:35:47 AM »
I don't believe the activating or "smacking" of the Wyeast pack increases the cell count significantly. I pulled this off the Wyeast web site:

"4. Does the cell count increase when the package is activated?

The cell count does not increase significantly when the package is activated..  The smack-pack is not designed to dramatically increase the cell count, it simply “activates” the yeast metabolism."

You can check out more at this link:  http://www.wyeastlab.com/faqs.cfm?website=1#r16

Hopefully, someone will be able to address my question as well.

Cheers

Offline Waldner

  • BeerSmith Brewer
  • ***
  • Posts: 36
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #3 on: November 08, 2012, 06:47:47 AM »
Getting ready to do my next starter but I'm still not sure how these two areas tie together or if they even impact each other. Does anybody have an idea as to whether or not the "Yeast Viability" percentage is supposed to be used to adjust the "Starter Pack Cell Count" in the section below?

Thanks

Offline philm63

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 371
  • Agis Quod Adis!
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #4 on: November 08, 2012, 12:33:35 PM »
If you are referring to the yeast's pop-up window (the one that shows up if you double-click on the yeast); no, you do not need to change that cell count because that is the starting count for that pack or vial - they'll typically start at 100 billion.

The calculators will use the Package Date you enter and do all the math for you including the starter size needed. Enter the recommended starter size in the "Starter Size" box and the number of cells it reads below that should match what is required above.

If you check the Stir Plate box, this will change your cell count dramatically and you'll have to readjust the starter size to get your cell count where it should be based on the recommendations.
On Tap: Oatmeal Stout, IPA
Fermenting: Air
On Deck: Kolsch

Offline Waldner

  • BeerSmith Brewer
  • ***
  • Posts: 36
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #5 on: November 08, 2012, 12:42:12 PM »
Thanks Phil, but I'm referring to the "Yeast Starter" tool under the "Tools" tab.

Do you know the details on how that is supposed to function?

Thanks again

Offline philm63

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 371
  • Agis Quod Adis!
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #6 on: November 08, 2012, 12:54:40 PM »
I just ran a little experiment and it seems to work fine if I leave the pack cell count at 100. It seems to force the starter size based on the viability calculated by your package date.

The Volume, Production Date, and OG seem to be the important variables - you set those based on what you know - and the software calculates your starter size. It'll even change it for you if you select Stir Plate. The starter pack cell count still seems to be tied to the typical cell count for a single pack or vial, so I don't think you need to change that.
On Tap: Oatmeal Stout, IPA
Fermenting: Air
On Deck: Kolsch

Offline tom_hampton

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 929
  • BeerSmith 2 Rocks!
    • Tom's Miata Racing Blog
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #7 on: November 08, 2012, 01:41:25 PM »
I'm not really worried about my pitch rate like some of you.  Those absurd pitch rates generated by mr malty are based on professional production where they try to push beer out in a hurry.  I'm just more curious than anything. My beer is just fine and from what I've had of Zainey's commercial offerings, better than his.

Wow.  You might want to get your facts straight. 

The pitching rates are NOT based on professional production.  They are based on Jamil's personal experiments as a homebrewer.  They were published LOOONG before he even thought about starting heretic.  he has been preaching 0.75 mil/ml/Plato for ales and 1.50 mil/ml/plato for Lagers since 2006....for HOMEBREW.

Chris White recommends 0.50mil/ml/plato and 1.0 mil/ml/plato for professional brewers.  The explanation that he has given  for the differenct (and lower qty's) is the different hydrodynamics, depth, and aspect ratio of the professional fermenters.  Essentially, more CO2 is held in solution in professional fermenters which suppresses ester production on the professional scale.  Therefore, they need to stress the yeast more to get the same flavor profile as homebrewers---or rather homebrewers don't need to stress the yeast as much.

The leading experts in the field all agree within a few percentage points on the desired pitching rates...from leading beer schools, to the heads of both major homebrew yeast companies (Charlie Bamforth, Chris White, Dave Logsdon, etc).   The pitching rates are in NO WAY designed around fermentation DURATION.  All of the above listed experts have stated that they were specifically designed around getting the best FLAVOR profile...For both Homebrewers, and professional brewers.  The exact numbers differ as described above.  But, NOT A SINGLE ONE would call the above recommendations absurd.   

I don't really care what you do...but, if you are going to get on here and "refute" the documented advise of worldwide respected experts...you owe it to everyone to back up your claims with facts and hard data.  Simply stating "my beer is better than his" really means absolutely nothing.  Great, you like your beer.  Does anyone else?  Have you won the Ninkasi, or Hombrewer of the Year?  How about a measurable fraction of as many NHC medals as JZ?  Have you done series after series of fermentation trials at different pitching rates, followed by double blind, triangle taste tests? 

JZ has done the tests, and has won the awards as a result.  He's shared every bit of knowledge that he gained in that pursuit.  It's rather comical that someone with no known reputation or credentials, would get on here (or anywhere) and simply say "That's crap. I don't do that, and my beer is way better than his." 
R.I.P.:Belgian Blonde
On Tap: Apfelwein, Kolsch(v2), Pumpkin Ale, Belgian Specialty 
Aging/Storing: Coffee Porter, Chocolate Porter, Flanders Red, English Barlywine
Fermenting: Maggie's Altbier
Next Up: PtE(1.1), Belgian Dubbel?

Working thru all BCS recipes

Offline Waldner

  • BeerSmith Brewer
  • ***
  • Posts: 36
Re: Yeast Viability vs. Starter Pack Cell Count in Yeast Starter Tool
« Reply #8 on: November 08, 2012, 02:09:39 PM »
Thanks Phil!

I never thought of trying that, it works! The yeast viability percentage must be tied into the calculation below it. Just as you said, each time I adjust the date without changing the starter cell pack count the starter size adjusts automatically.

Cheers!