# How much do you trust those web yeast calculators?



## carniebrew (30/1/14)

I split a pack of 3068 with a mfr date of Aug 29, 2013 two ways back when I bought it. Made a starter with the first half using yeastcalc.com, and everything worked out fine. Top cropped it after a few days, and the resultant yeast is now sitting in a 50ml test tube, next to the original split. Both look to have about the same amount of yeast in them.

I'll be brewing another hefe in a week or so, and went to work out my starter size for the 2nd half of the split. yeastcalc.com is now dead, and someone put me onto Brewer's Friend instead. However, BF says that a liquid yeast with a mfr date of Aug 29 is officially kaput, 0% viable cells. In fact is tells me any liquid yeast older than 143 days is 0%.

I find that very hard to believe. I found a 2565 Kolsch yeast in my fridge a couple of weeks ago with a Mfr date of October 2012. I smacked it for fun, and although it took 4 days, it swelled up more than I've ever seen a Wyeast activator swell before, so much so that I was almost certain it was going to burst (I put it in the fridge and am thinking of doing some stepped starters with it). That yeast is over 400 days old, and is obviously viable.

Mrmalty.com tells me my 154 day old 3068 is 10% viable, which at least gives me something to work with (5 billion cells given it was a 50/50 split). Just wondering if anyone has a better model to work on for liquid yeast viability?


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## MartinOC (30/1/14)

:icon_offtopic: Yeastcalc is dead?? Any details? Anyone?


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## Online Brewing Supplies (30/1/14)

I dont trust web yeast calcs, the only way to know is do a cell count via a microscope and a viability test.
Way to many variables in the punch in your date and get an answer in packs, you will probably pitch more than you need.
Nev


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## carniebrew (30/1/14)

MartinOC said:


> :icon_offtopic: Yeastcalc is dead?? Any details? Anyone?


A few days ago it was coming up with a page not found type error, now it's one of those generic ISP pages trying desperately to re-direct you to another site vaguely related to yeast.


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## slcmorro (30/1/14)

http://www.mrmalty.com/calc/calc.html


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## slcmorro (30/1/14)

Sorry. Didn't read the thread at all it seems!


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## MartinOC (30/1/14)

Could some bright spark with greater computer knowledge than me please explain how to achieve what they're saying in posts #7, 14 & 15 (or better yet, save it for the benefit of all here)?

http://www.homebrewtalk.com/f163/yeastcalc-com-456442/

I know we're not supposed to reference or discuss other forums, but this piece of kit is worth saving!


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## adryargument (30/1/14)

If you left 1000 people in the arctic for 60 days with no food the survival rate is 0%.
Doesnt mean bear grills aint gonna go starwars, live inside a yeti fight rebel troops until help arrives, beating all odds.

Theres always going to be a bunch of super-yeast that will outlive the others.

In the end its a vial of dead yeast = a vile of food for the left over yeasties.

4 days is 8 birth cycles for yeast, When you compare that to todays teens where 50% are knocked up at 12 you may as well call it 12 birth cycles for the yeasties. No wonder it welled up nice and big with all that extra food.

Its a calculator thats based on the normal behavious of yeast. Different strands will have different viability rates / individual cell viability rates.
When your going for a 2-8 week old pitch test its going to be failly accurate. If your using it to calculate 8 month old yeast then your on your own buddy.


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## brewtas (30/1/14)

From the Braukaiser blog:




> I expect yeast growth calculators to have an error of +/- 15% or more.


It's just a passing comment in a post talking about yeast growth rates in stirred starters that's worth reading in its own right.


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## carniebrew (30/1/14)

MartinOC said:


> Could some bright spark with greater computer knowledge than me please explain how to achieve what they're saying in posts #7, 14 & 15 (or better yet, save it for the benefit of all here)?
> 
> http://www.homebrewtalk.com/f163/yeastcalc-com-456442/
> 
> I know we're not supposed to reference or discuss other forums, but this piece of kit is worth saving!


The good news is someone's copied the yeastcalc.com calculator onto their own website, here: http://www.cheapmonkeys.com/yeastcalc/

Basically it just seems that whoever it was that owned yeastcalc.com either forgot, or decided not to pay their domain name renewal fee. Looks like Mr Cheap Monkeys is going to host it until yeastcalc.com comes back (or until someone who owns the IP threatens to sue him...)

Good find on that topic. Oh, and I don't believe AHB have any rule about discussing or referencing other forums. Rather the "rule" is that you don't come here spruiking other forums, with posts like "AHB is shite, you should give it up and come over to xyzbrew.com instead".


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## carniebrew (30/1/14)

Oh and what's interesting is that yeastcalc.com thinks my Aug 29 packet of 3068 is 28% viable, which I think would be much more realistic.


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## Black Devil Dog (30/1/14)

At least with yeastcalc you have the option of selecting which scale you want to use, (Jamil's or Kai's) Kai's seems a lot more scientific and more realistic. Hope it comes back up soon.


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## elcarter (30/1/14)

http://www.brewersfriend.com. 

Has always provided me with good results.

Variables will always be there at the home brew level without a lab but if you always use the same calculator you add a constant to the equation.


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## Markbeer (3/2/14)

Agreed. When i stumbled on this a year and a half ago i have used it since. A nice flexible realistic calculator.




elcarter said:


> http://www.brewersfriend.com.
> 
> Has always provided me with good results.
> 
> Variables will always be there at the home brew level without a lab but if you always use the same calculator you add a constant to the equation.


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## Wolfman (7/2/14)

carniebrew said:


> The good news is someone's copied the yeastcalc.com calculator onto their own website, here: http://www.cheapmonkeys.com/yeastcalc/
> 
> Basically it just seems that whoever it was that owned yeastcalc.com either forgot, or decided not to pay their domain name renewal fee. Looks like Mr Cheap Monkeys is going to host it until yeastcalc.com comes back (or until someone who owns the IP threatens to sue him...)
> 
> Good find on that topic. Oh, and I don't believe AHB have any rule about discussing or referencing other forums. Rather the "rule" is that you don't come here spruiking other forums, with posts like "AHB is shite, you should give it up and come over to xyzbrew.com instead".


Looks like this link not working either?

As I split all my yeasts I am now in trouble! Yeastcalc worked out the % of viable yeast, yes it may not have been accurate but worked for me.

Any other calcs people use that allows split yeast?


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## brewtas (7/2/14)

As was posted earlier in this thread: brewers friend. It's probably the best calculator of the lot.


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## Wolfman (7/2/14)

brewtas said:


> As was posted earlier in this thread: brewers friend. It's probably the best calculator of the lot.


Yes tried that Calc. But it does not ask for the starting XXXBillion of yeast cells.

When splitting with Yeastcalc I would input 20 here as I split them into 5's. Yeastcalc also gave you the preferred limits on growth rate.


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## brewtas (7/2/14)

It does both of those things, you need to have a proper look at it. It's got more options that yeastcalc did.


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## Wolfman (7/2/14)

Of ok. So where it says "packets/vials" do I just input .2?


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## brewtas (7/2/14)

Scroll down and the first thing under "Part 2" where the starter making info is you should see a box where you can enter the starting yeast count.


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## dicko (7/2/14)

Wolfman,
If you input .25 instead of 1 into the number of yeast packs then it will calculate as one quarter of a full pack relative to the date.

I use this calculator and that is what I do when I split a pack 4 ways.

Cheers


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## dicko (7/2/14)

Yes .2 will give you the calcs for a fifth of the pack.


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