Stepped Yeast Starter Calculator

[Amber Fluid]

Strange how everything is in ml and liters but the batch volumes are in US Gallons. :blink:

 

[stux]

Strange how everything is in ml and liters but the batch volumes are in US Gallons. :blink:

In the US, Yeast starters are often done in metric

I assume this is the yeast scientists doing

 

[dustinsullivan]

In the US, Yeast starters are often done in metric

I assume this is the yeast scientists doing

Americans are a little confused when it comes to measuring things.
I love the metric system, very easy to use. Unfortunately I grew up using U.S. system, I have a hard time visualizing the metric system, but I'm getting better. Homebrewing has helped a lot in that area. I am working on putting a menu in to change the volume units to metric. Thanks for the input.

 

[Steve@PMF82]

A very good idea. Here is my take on the whole thing YeastCalc

I have to agree with stux, this is very neat! Bookmarked!

Seems to use the same calculations on inoculation rates producing X amount of cell growth as i had been doing from the charts out of the yeast book.
I still make initial assumptions on my small amounts of saved yeast cell count with Mrmalty.

Its so handy i dont mind having to convert the gallons

 

[dustinsullivan]

I have to agree with stux, this is very neat! Bookmarked!

Seems to use the same calculations on inoculation rates producing X amount of cell growth as i had been doing from the charts out of the yeast book.
I still make initial assumptions on my small amounts of saved yeast cell count with Mrmalty.

Its so handy i dont mind having to convert the gallons

I added a conversion menu today, just for you aussies . It looks a little clunky, but maybe I can refine it some. And you are correct, it is based on the same data. I plotted the data on page 140 of White's 'Yeast" book, in excel and came up with a nice exponential curve that seemed to fit Mr.Malty's growth rate as well.

 

[Amber Fluid]

Good work Sulli. Thanks

 

[stux]

What was the source for the yeast viability vs age?

 

[dustinsullivan]

Chris White

 

[dustinsullivan]

Hello Gents,

I put together some charts showing how I got at the formulas that I'm using in my calculator, thought it might be of interest to some of you. Anyway, check it out, and let me hear your thoughts.

Growth Charts

 

[stux]

I enjoyed your growth charts

The problem with the viability is if you enter June 3rd, 2011, then it spits out 0% viability. Mr Malty spits out 10% viability, and BeerSmith2 spits out 28.85%

Vast difference

Looking at my 4month old vials, I can certainly say that they are better than 0%

And I don't think there is a way for me to override the viability :-\

Might be worthwhile doing a similar curve analysis against the Mr Malty calculator, as I think its numbers are fairly good...

PS: I haven't read "Yeast", its on my Christmas wishlist

 

[stux]

I enjoyed your growth charts

The problem with the viability is if you enter June 3rd, 2011, then it spits out 0% viability. Mr Malty spits out 10% viability, and BeerSmith2 spits out 28.85%

Vast difference

Looking at my 4month old vials, I can certainly say that they are better than 0%

And I don't think there is a way for me to override the viability :-\

Might be worthwhile doing a similar curve analysis against the Mr Malty calculator, as I think its numbers are fairly good...

PS: I haven't read "Yeast", its on my Christmas wishlist

More so, Although White Labs say that the Shelf Life for their yeast is 4 months, that is not the same as the viability, rather its based on a retail realities of expectations of minimum viability

"
The shelf life for White Labs Yeast is four months. Yeast used after this point is usually fine, but lag times will be longer. There will be living yeast in most vials for 6-12 months, so if a starter is made to activate the yeast, successful fermentations can be carried out with aged yeast.
"

So, I would guess that at a minimum viability should be >0 for 6-12 month old yeast

From my quick checks Mr Malty uses 1% for >365 days and 10% for >4 months

 

[Steve@PMF82]

I enjoyed your growth charts

The problem with the viability is if you enter June 3rd, 2011, then it spits out 0% viability. Mr Malty spits out 10% viability, and BeerSmith2 spits out 28.85%

Vast difference

Looking at my 4month old vials, I can certainly say that they are better than 0%

And I don't think there is a way for me to override the viability :-\

Might be worthwhile doing a similar curve analysis against the Mr Malty calculator, as I think its numbers are fairly good...

PS: I haven't read "Yeast", its on my Christmas wishlist

I had the same viability issue.

I just punched in what ever date made it say the viability i get from Mr malty, then use the calculator as normal.

 

[dustinsullivan]

I agree the viability seems a little on the high side. I personal have made starters from really old yeast and they fermented out just fine, I think viability is a pretty generic number and is very hard to pin down due to so many variables on handling and storage. my calculator uses 0.6% viability lost per day, and I thought that's what mr. malty used as well, I'll be looking into this some more. it would be very easy to lower it. But one way around it is to set the date to anytime in the future, the viability then goes to 100% and you can just manually enter a cell count to correlate with whatever viability you want.

 

[dustinsullivan]

Okay, I made some adjustments. Turned out to be easier than I thought. Give it a try now, it should be pretty close to mr. malty's calculations for viability.

 

[stux]

Cool

Viable Cell Count seems to be ignoring Initial Cell Count when its in the 10% viable range

So, if you are at 84% viability, then modifying initial cell count seems to work as expected, but if its in the 10%, then it seems to assume 100billion Initial Cells and ignores the Initial Cell Count (which could be 50 or 25 billion for example)

The red/green cell counts is a nice touch

PS: this is about to become my go-to yeast starter calculator

 

[Hogan]

Nice job Sulli. I like it.

Cheers, Hoges.

 

[dustinsullivan]

<br />Cool<br /><br />Viable Cell Count seems to be ignoring Initial Cell Count when its in the 10% viable range<br /><br />So, if you are at 84% viability, then modifying initial cell count seems to work as expected, but if its in the 10%, then it seems to assume 100billion Initial Cells and ignores the Initial Cell Count (which could be 50 or 25 billion for example)<br /><br />The red/green cell counts is a nice touch <img src="http://www.aussiehomebrewer.com/forum/style_emoticons/default/smile.gif" style="vertical-align:middle" emoid="" border="0" alt="smile.gif" /><br /><br />PS: this is about to become my go-to yeast starter calculator <img src="http://www.aussiehomebrewer.com/forum/style_emoticons/default/wink.gif" style="vertical-align:middle" emoid="" border="0" alt="wink.gif" /><br />

<br /><br /><br />

Ah, I see. I'll have to go back in and fix that, good catch. I'm glad you find it useful, I hope other people will as well.

 

[dustinsullivan]

Okay, I think I've got it. Give it a go now. I really appreciate you blokes giving me some productive feedback on this thing, I've posted it on several different brewing forums, and you guys are the only ones who have been helpful in working out the bugs. Thank You.

 

[Yob]

can you add an option to use L for batch size?

you didnt look too hard unless it was just done...

 

[Steve@PMF82]

you didnt look too hard unless it was just done... yes mate he made the addition earlier just for us aussies

View attachment 49793

Americans are a little confused when it comes to measuring things.
I love the metric system, very easy to use. Unfortunately I grew up using U.S. system, I have a hard time visualizing the metric system, but I'm getting better. Homebrewing has helped a lot in that area. I am working on putting a menu in to change the volume units to metric. Thanks for the input.

I added a conversion menu today, just for you aussies . It looks a little clunky, but maybe I can refine it some. And you are correct, it is based on the same data. I plotted the data on page 140 of White's 'Yeast" book, in excel and came up with a nice exponential curve that seemed to fit Mr.Malty's growth rate as well.