Stepped Yeast Starter Calculator

[stux]

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.

Welcome

Its good to have someone responsive to feedback

I think the tab order could use a bit of improvement too

I think it should go from the Top left cell across and down

at the moment it goes from the yeast cells, back up to the top, then back down to the steps... which I think could be on purpose... but I keep on clicking in the batch size, and then tabbing and it skips straight to the steps over the yeast, which is not what I expect

 

[Brad Churchill]

That is one brilliant calculator Sulli.
Well done and thanks!!

Cheers Brad

 

[dustinsullivan]

To be perfectly honest, I haven't even set the tab order. I hadn't tried tabbing through the application till now. I see what your saying; the order doesn't make any sense. It definitely needs to go from top left across and down, that makes the most sense to me as well. I'll work on it tonight. Thanks again.

 

[dustinsullivan]

Got it. Nice suggestion Stux. That's much better.

 

[stux]

Heya sulli,

I noticed that you've now registered the domain http://www.yeastcalc.com, nice

Also, you don't have a contact/suggestions link that I can see

Perhaps put a link to a thread on this forum

Anyway, I have a suggestion

I would like to see the multiplication factors between steps,

So, for example, I'm stepping up from 9.75B cells to 40B, I'd like to see the growth factor of x4.1

I figured a good place would be to just put some text next to the result field for each step

 

[dustinsullivan]

Heya sulli,

I noticed that you've now registered the domain http://www.yeastcalc.com, nice

Also, you don't have a contact/suggestions link that I can see

Perhaps put a link to a thread on this forum

Anyway, I have a suggestion

I would like to see the multiplication factors between steps,

So, for example, I'm stepping up from 9.75B cells to 40B, I'd like to see the growth factor of x4.1

I figured a good place would be to just put some text next to the result field for each step

Hello Stux,

Yes, I have been wanting to put a Feedback/Contact link up for awhile, it is done now. :beerbang:

Not sure about the growth factor though, how useful is this information really? I also think it could create a slew of questions from less knowledgeable users.

 

[cdbrown]

sulli,

excellent site, am now basing my starters and steps on your info. A potential improvement is to state clearly on the site to try and get the 50-100 target innoculation rate. It's not mentioned on the care and feeding page even though it states the innoculation rate is important, and unless you hover over innoculation cell the user wouldn't really know if the rate is right. Is it possible to have the colour change when outside the target just like the total finished cells is red when it's below target.

Also what is the impact of say stepping up a starter where the first step innoculation is only 17M/ml compared to trying for 50M/ml?

Cheers
-cdbrown

 

[stux]

Hello Stux,

Yes, I have been wanting to put a Feedback/Contact link up for awhile, it is done now. :beerbang:

Not sure about the growth factor though, how useful is this information really? I also think it could create a slew of questions from less knowledgeable users.

I try to keep my steps between 4-5x increase

Being able to see the increase as a multiple makes it easier for me to keep my steps even, generally favouring large steps early on rather than later

 

[cdbrown]

I try to keep my steps between 4-5x increase

Being able to see the increase as a multiple makes it easier for me to keep my steps even, generally favouring large steps early on rather than later

Do you find that in order to get the 4-5x increase in the first step or so your innoculation rate is about 15-20M/ml? An example is a lager yeast from November last year = 27B viable cells. 1.5L starter on stir plate produces 135B cells with an innoc rate of 18M/ml. Targeting a 50 innoc rate, the starter would be 0.5L and the outcome 82B viable cells (x3 growth).

 

[hando]

Is this going to be airlocked?

Well done - it's a great calculator!

 

[stux]

Do you find that in order to get the 4-5x increase in the first step or so your innoculation rate is about 15-20M/ml? An example is a lager yeast from November last year = 27B viable cells. 1.5L starter on stir plate produces 135B cells with an innoc rate of 18M/ml. Targeting a 50 innoc rate, the starter would be 0.5L and the outcome 82B viable cells (x3 growth).

I find the biggest factor is actually time. If there are enough nutrients and constant O2, then the yeast will continue growing until they use up the nutrients, or reach a certain density.

That's been my experience anyway, but this means spending 36-48 hours on a step

BUT its not like I'm pulling out a microscope and counting cells

I tend to do 2 or 3 step starters over a period of week because I'm starting from generally very old 1/4 packets of wyeast. From readings I've done, the advice is to do the bigger steps first

http://www.maltosefalcons.com/tech/yeast-p...s-and-practices

 

[stux]

Example of a yeast step i just did this morning

 

[dustinsullivan]

sulli,

excellent site, am now basing my starters and steps on your info. A potential improvement is to state clearly on the site to try and get the 50-100 target innoculation rate. It's not mentioned on the care and feeding page even though it states the innoculation rate is important, and unless you hover over innoculation cell the user wouldn't really know if the rate is right. Is it possible to have the colour change when outside the target just like the total finished cells is red when it's below target.

Also what is the impact of say stepping up a starter where the first step innoculation is only 17M/ml compared to trying for 50M/ml?

Cheers
-cdbrown

The 50-100 million cells/ml target inoculation rate is based off of data from Chris White's book "Yeast". It appears to be the most effective inoculation rate for optimizing the health and growth rate of the yeast. Ideally, you want to grow your yeast in a large enough volume of wort to ensure optimal yeast health and to get a decent amount of growth for your trouble. As the inoculation rate decreases the growth rate increases, this places more and more stress upon the individual yeast cells as the number of divisions per cell increases. So, in other words, you will get the most bang for your buck in the 50-100 million cells/ml range, but decreasing or increasing the inoculation rate will still produce yeast cells capable of doing their job.

 

[Wolfy]

BUT its not like I'm pulling out a microscope and counting cells

I have two microscopes, but to be totally honest have never yet bothered to use them for counting yeast.
However, if you don't count cells and test your formula and theories how do you know that the information you have published is correct?

 

[stux]

I have two microscopes, but to be totally honest have never yet bothered to use them for counting yeast.
However, if you don't count cells and test your formula and theories how do you know that the information you have published is correct?

Yeast slurry volumes

 

[TSMill]

Do you find that in order to get the 4-5x increase in the first step or so your innoculation rate is about 15-20M/ml? An example is a lager yeast from November last year = 27B viable cells. 1.5L starter on stir plate produces 135B cells with an innoc rate of 18M/ml. Targeting a 50 innoc rate, the starter would be 0.5L and the outcome 82B viable cells (x3 growth).

The 50-100 gives you the best hang for your buck, all else being equal. yes in that example the 1.5L starter results in a higher yield, but a 0.5L starter followed by a 1L starter gives you more cells (206) for the same 1.5L total word used.

 

[stux]

Alright Stux, because I like you, and because I'm curious to see what kind of reactions I get. I'm calling it "doublings" because thats what it is, but it is the same as growth rate.

Just so you know, this might be coming back down if I get too many noob questions about what it is and why it is there.

Still getting version 2.15 at the moment

 

[dustinsullivan]

Still getting version 2.15 at the moment

Try refreshing your browser.

 

[dustinsullivan]

Nevermind, I can't get it up on my laptop either, it must not have posted to the server correctly. I'm in class right now, but I'll try to get it working when I get home in a few hours.

 

[Steve@PMF82]

The new version is online now, but I've been thinking about this growth rate number today, and I don't think it is such a good idea. I think it is going to confuse people. If you make a 1.5 liter starter with 100 billion cells on a stir plate you get a growth rate of 1.76, but if you make a 3 liter starter with 100 billion cells on a stir plate you get a growth rate of 2.8; obviously a 2.8 growth rate is better than 1.76 growth rate, in fact the bigger I make my starter the bigger the growth rate becomes, and we all know that bigger is better right?
Wrong. Bigger is not better; bigger starters put more stress on the yeast, resulting in less healthy yeast cells.
Joe brewer is going to be confused by this seeming paradox, which makes the growth rate number meaningless.
The number you should be looking at is the inoculation rate.

Can you make the inoculation rate number go red/green if it falls outside/inside the recommended range?
Like the pitch rate and finished cell count.