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Viability Calculations with different calculators

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mclaughlindw4

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I am currently comparing yeast calc to mr.malty. I put in a production date of 11/18/2012. Yeastcalc gives me 60% viability and Mr.Malty gives me 30%

So I made a 1.5 L starter for a 1.041 OG beer. According to Mr.Malty I am right on with my counts but according to Yeastcalc I overpitched by 60 billion cells (or about 36%). Now I am concerned I may have overpitched which would be a bummer because I am making a saison.

The weird thing is, I used yeast calc the other day and I swear it gave me 30% and not 60%. Am I just going crazy?

I have searched through threads and read both sites as well as wyeast and white labs sites for faq and can find very little info on this topic.
 

Kaiser

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Don't put to much trust into these yeast calculators. there are many factors for yeast growth that are not considered. I also think that the Mr malty calculator underestimates yeast growth in stirred starters for lower innoculation rates.

Kai
 
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mclaughlindw4

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I can find tons of info about pitching rates, growth rates, etc, and I suppose I could do my own calculations in this respect. But if I don't know what baseline I am starting with then everything else is meaningless.

Wyeast and white labs have basically no info (that I could find) about viability of their product as it ages. Wyeast basically says you don't need a starter, unless you do. Mr.Malty and YeastCalc tell you nothing about how they came up with the calculations they use (for viability), in addition to the fact that the do not agree with eachother.

I am just looking for some guidance or opinions on how to determine viability of my yeast, as this seems to me like it would be the basis for attempting to get the right pitch rate.
 

iaefebs

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This may not be the correct timeline, but it is how I saw this issue evolve over the last couple years. 1st thing to happen was White labs and Wyeast sold yeast to us homebrewers in 5 gallon pitchable containers. Everyone was happy. Then Jamil started to say that we needed more yeast cells and argued for a higher pitch rate and came up with a online calculator.. Chris White, didn't agree and asked for homebrewers input. Beersmith was using it's own calculations. Chris and Jamil then eventualy collaborated to write a book together. If you get the book "Yeast" by Chris White and Jamil Zainasheff it has great information. That left Beersmith and MR Malty at odds with each other and Beersmith challenged Mr Malty saying their formula was more accurate. Now Beersmith and Mr Malty agree, Beersmith uses Mr Malty calculations. I didn't come across YeastCalc till late in the game when I started doing step starters, viewing past history I'm going to guess that one day YeastCalc will agree on the viability issue. I use Beersmith and Mr malty for my 1st step and use Yeastcalc for the next steps. I could use Mr Malty or Beersmith for step starters but YeastCalc looks easier. Until I actually decide to start doing my own cell counts I have a blind faith in the people that have done the previous research. What I try to keep in mind is that we brewed some great beers back in the day when you pitched a vial or smack pack just by getting the freshest yeast at the LHBS. Some of the members here have gotten into cell counting and maybe they can offer some additional info on non laboratory results.
 

Kaiser

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This gives some insight into the work I'm doing right now: http://braukaiser.com/blog/blog/2012/11/03/estimating-yeast-growth/

The problem with the yeast calculators out there is that there is very little information on the research that supports their models. To my knowledge there are 2 major sources: White/Zainacheff and Wyeast. I asked both if they used stir plates for their stirred starter curves and did not get an answer back. Because still and stirred starters behave differently when it comes to yeast growth one cannot derive the "stirred starter" curve by extrapolating the non stirred starter curve. You really have to do a lot of stirred starters and that's a bit more resource and time intensive than simply using an array if non agitated starters inoculated with different amounts of yeast.

mclaughlindw4, I put your data into the Brewer's Friend yeast calculator, which implements my model, and I get about 290 Billion cells if I assume that the yeast in the vial is about 50% viable. That's just another point for you.

As for assessing yeast amount w/o counting, try weighing the slurry. Simply note the empty weight of the flask and the weight of the stir bar. Then when the yeast has settled decant the starter beer and weigh the flask. Ale yeasts like WLP001 have about 2-3 Billion cells per gram sediment. Lager yeasts are more like 4-5 B/g. WLP 002 also has about 4-5 B/g. I'm still working on refining these numbers and include more strains.

Kai
 

iaefebs

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If I remember correctly, when Beersmith 2.0 first came out the differences in the calculators was for the growth factor on a stir plate. MrMalty used less than 2 and Beersmith used greater than 2.5. I know that Brad and Jamil got together on this.
 
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mclaughlindw4

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Ok thanks everyone! Lots of good info to think about.
 

Kaiser

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iaefebs said:
If I remember correctly, when Beersmith 2.0 first came out the differences in the calculators was for the growth factor on a stir plate. MrMalty used less than 2 and Beersmith used greater than 2.5. I know that Brad and Jamil got together on this.
thanks for that info. Do you know how this growth rate is defined? I.e what do the 2 and 2.5 mean?

Kai
 

thadius856

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Wyeast and white labs have basically no info (that I could find) about viability of their product as it ages. Wyeast basically says you don't need a starter, unless you do. Mr.Malty and YeastCalc tell you nothing about how they came up with the calculations they use (for viability), in addition to the fact that the do not agree with eachother.
Wyeast gives out this information, just in an odd way. They have both a homebrewer and a commercial customer base. They seem to feel the need to dumb down the science of the Activator smack packs to make their product more accessible to less experienced brewers. Guess what, it works. I went through at least 5 packs of 1056 before I realized I could get by with US-05 cheaper and without a starter.

The advanced information is out there from Wyeast, you just have to go to their commercial version of the site. Here's a very good interview... a full hour of nothing but yeast. Super informative. Make sure to pause at times when information starts to get thick.


As for a baseline, they state that they measure the cell count on each batch, then concentrate or dilute to get you 100 billion cells in each Activator pack on packaging day. They don't provide viability information that I know of, probably because it's strain-dependent and based more on how it's handled than anything else.

White Labs, from best I know, is 75 - 150b cells per vial. Makes no sense to me that they'd do that. All my vials have been about 35% solids by volume, which is odd, because of the great variability in the solids sizes of each strain.
 
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highgravitybacon

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I wonder about this topic. Maybe its more fuss than necessary. Clearly too little yeast is bad, too much yeast bad also. But yeast are adaptable. How too few is really To Few? Same with too much? What is the fat part of the curve where it really doesn't matter?

If you brew varied beers, with different yeast strains, are the calculators going to even be comparable? I dont think in these cases it is.
 
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mclaughlindw4

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Mr. Malty and YeastCalc are now agreeing with eachother on 30% viabilty for yeast from
11/28/12. I don't know what happened yesterday, I re-entered everything 3 or 4 seperate times and they were not in aggreement.

I will use the calculators for now and see how things work, as long as they aren't randomly disagreeing with eachother.

This is really a different topic but, one question I have is why are people using microscopes to count cells? I used to do that stuff for work and we used petrifilm, it seems more difficult and expensive to use microscopes. In addition how would you know if the cells you were looking at were alive or dead?
 

Kaiser

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This is really a different topic but, one question I have is why are people using microscopes to count cells? I used to do that stuff for work and we used petrifilm, it seems more difficult and expensive to use microscopes. In addition how would you know if the cells you were looking at were alive or dead?
Microsopes are the quickest of the more affordable ways for home brewers to count cells. It alsos allows you to count cells that clump together b/c you are looking at the cells.

There are staining techniques that can help you to identify dead cells. While they are not perfect they are oftentimes good enough. My take on dead cells is that if you have to worry about a large percentage of the yeast being dead you should grow a fresh culture. That way you know that most of the cells are alive.

What's petrifilm? is that a technique where you count colonies grown from a sample?

Kai
 
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mclaughlindw4

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Here is a link (hope it works) if not just google 3M yeast and mold petrifilm:

http://solutions.3m.com/wps/portal/...S7P92O3O87000000_nid=VMHC06ZPSZbe29BDXSBJ7Fgl

Briefly: You would make serial dilutions of your slurry, and 1 mL of it goes onto the film. Dilute by factors of 10 or 100 at a time and apply the dilution factor to the final count (i.e for a 1 to 100 dilution you would multiply your count by 100). You need to dilute enough to get the count down to around 100 cells on the film so you can easily read them. For 100 billion cells would be many dilutions (to lazy to do the math now).

The problem I guess is you have to incubate for 3 to 5 days at 25 C so results aren't immediate. Now that I think of it I guess you need pipettes for this, but I don't see how you wouldn't for the microscope method either. All I know is that I used to work in a food micro lab, we had microscopes but we only used them for identification. Counts were done on plates or film, not sure exactly why but there must be a reason. I would guess its more accurate and probably faster (not from an overall time but from a labor standpoint).

Aside from the pipette all you would need is to buy the film, and most people that are doing counts (I am sure) already have a way to incubate something at 25 C. In addition I believe you would only be looking at live cells I think (good way to do some viability experiments!)
 
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mclaughlindw4

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Now that I think of it, it is definetely faster. Maybe not more accurate if you have good technique and know what you are doing with microscope.
 

Kaiser

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Now that I think of it, it is definetely faster. Maybe not more accurate if you have good technique and know what you are doing with microscope.
Thanks so much!!!

I was looking for that stuff. I have seen it used on a kids science show my daughter watches but didn't know what to look for. I think Steve (woodlandbrew) would be interested as well since he wanted to compare staining to plate counts.

It's kinda expensive ($80 for pk of 50) but may be worth it if it has a good shelf live.

But you still want a microscope if you use this since you have to make sure that your sample doesn't have clumps of yeast. Each clump of yeast would show up as only one colony and you would count less cells than there actually are.

Kai
 
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mclaughlindw4

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no problem, thanks for all your input too. I was planning on maybe waiting for the next yeast counting thread to suggest this idea as well. I guess I didn't know it was that expensive since I never had to buy it!

Not sure about the clumps of yeast. It was nothing we ever thought about it. We use sonication at my current job to keep things from clumping:
http://www.sonicator.com/sonicatorQ55.aspx
I think these things are really expensive though and not sure how they would work on yeast (might just destry them)
 

Kaiser

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I think sonication works for breaking up yeast clumps but there are less expensive ways to do that through the use of chemicals that can disrupt flocculation.

Kai
 

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