# yeast starter step up



## rude (29/10/14)

Ok having trouble understanding the yeast calc
I am going to brew a Munich Dunkel down the track so thought I'de play around with the yeast calc
I will be using wyeast 2206 lager yeast wort 25 Litres @ 1050 lets presume the yeast is the latest date ( I know this doesnt happen but just for theory sakes)
Initial cell count 100 billion viable, viable cell count 96 billion
Optimal pitching rate 18.5 million/ml, cells needed 464 billion
Using a stir plate 5 Litres pitching rate 19.2 millions/ml gives me 465 billion cells at the finish
The growth rate is 3.84
After reading a little bit on here ( yeast stepped starter calc by puffer) another thread about (confused about lagering times)
the optimal stepp up is between 5x to 10x Im presuming this is the growth rate
So if I am right in my thinking a growth rate of 5x that would give me 8 Litres at 577 billion cells too much, inoculation rate 12 too low
Mr Malty doesnt give you a growth rate & says I need 5.14 Litres 1 pack for 463 billion cells
So I would need a big flask (only have a 5L) to make this starter because I cant do a 2.5 Litre starter decant then do another 2.5 Litre because I am not stepping up in the right proportions for the best growth 5x for lagers 10x for ales
Not sure I am on the right track here probably not please somebody
I also realise oxygen & nuetrients are very important I want to pitch cold so need the right starter for this
I have had a bit of a go at wyeast pitch rate growth calc but the imperial does my head in


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## siege (29/10/14)

If you want to build your understanding of yeast growth read through some of the experiments at http://braukaiser.com/

If you want a stepped starter calculator use http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/

Is there a reason you don't feel you can decant off the beer from each starter step and just pitch the thin/thick yeast slurry into the next step? 

With only 25L batches you definitely shouldn't need any bigger than a 5L flask if you just decant. I get by with a 1L and a 3L


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## Black n Tan (29/10/14)

My understanding is the 10-fold step is referring to the size of the starter volume. It is more relevant for yeast propagation from slants/petri dishes/very old vials of yeast i.e., very low initial yeast numbers. For example you may start with 10mL starter then step up to 100mL then up to 1L when pitching very low numbers of yeast. This means the pitching rate is ideal for growth. For making a yeast starter from a fresh white labs/wyeast pack it is not so relevant IMO. For starters (excuse the pun) the minimum recommended starter size is typically 1L if you let the yeast ferment out, less than this and the yeast can end up less healthy than they started. So for a 1.050 lager @42L I usually do a 1L starter followed by a 4L starter. Certainly not 10-fold. In reality your yeast will be some weeks old. I use Beersmith to calculate my starter size (IMO it handles the stirplate growth factor increase better than MrMalty, but that is another discussion) and it indicates a 4L starter should be adequate for a 1-month old pack of yeast for 20L @1.050.


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## danestead (29/10/14)

The 5 to 10 x is referring to the increase in size of your starter liquid, no the growth of the yeast. For example, if you were doing a 2 step starter and you started with a 500mL starter, the next step would ideally be 2.5-5L.

I find the yeast calculator at the following link easier to use, especially for stepped starters. If you click the zamil zainacheff option in the aeration method drop down boxes it will use the same growth equations as the mr. malty site (which is zamil). If you dont have a stir plate, just click your applicable option.

http://www.cheapmonkeys.com/yeastcalc/

It is also worth mentioning, ideally, the maximum inocculation rate is 100-200 billion yeast per litre of starter. If you had a 100% viable packet of 100B yeast, this means the smallest starter you would ideally make is 500mL-1L. This results in healthier yeast at the end.

Example.
25L @ 1.050 with Lager yeast
50% viability
stir plate (zainacheff)

First step 500mL starter - smallest id want to go (refer innoculation comment above) = 113B yeast
2nd step 4L starter - 459B yeast (this starter is 8x bigger than the original 500mL therefore fits the ideal)


Edit: Beaten by ^^^^^


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## rude (29/10/14)

Thank you you have made it all seam easy now
Dane I do use that calc I think you put me onto it before
I was going too big first step so 500ml then to the 4000ml
I do ferment out then decant so no prob there siege just got a bit confused with the ratios
Yes I need to do a bit more reading
Thanks all will have a look at beer smith cheers black & tan, Dane & seige


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## solipsist (18/12/14)

siege said:


> Is there a reason you don't feel you can decant off the beer from each starter step and just pitch the thin/thick yeast slurry into the next step?


This is my thinking on stepping yeast starters. Make starter, decant liquid, pour fresh cool wort on top.

Here is a quick guide on using the same container for multiple step ups (ie. 1x starter size steps - a lot less than the 5x to 10x that is discussed for optimum growth). http://billybrew.com/stepping-up-a-yeast-starter

For instance, you can use a 3L Erlenmeyer to get to 450 billion cells with 3 consecutive 3L starters, decanting between each. Obviously there is a limit to how many times this can be repeated (ie. when you are reaching inoculation rate of 100 mil cells / ml of starter).

I'm guessing the 5x to 10x step up size is for maximum growth (if you are not limited by container size), but as long as you are below 100mil cells / ml inoculation rate you aren't affecting yeast health by having smaller steps than 5x.


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## TheWiggman (18/12/14)

solipsist said:


> This is my thinking on stepping yeast starters. Make starter, decant liquid, pour fresh cool wort on top.
> 
> Here is a quick guide on using the same container for multiple step ups (ie. 1x starter size steps - a lot less than the 5x to 10x that is discussed for optimum growth). http://billybrew.com/stepping-up-a-yeast-starter
> 
> ...


This was my approach and I don't believe it's the right one. If the yeast gets exposed to a small quantity of wort it effectively gets 'trained' to that volume and become less and less suitable for full volume (when it's eventually pitched) the more you do it. Unless you're suggesting you split off 2/3 of the yeast slurry and then do 3 separate 3l batches, which is ugly. 
I've watched the video and it lines up with what you're saying. Discussions on the forum previously as linked above, specifically comments made by MHB, don't support this approach as it apparently compromises the health of the yeast.


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## Bomber Watson (18/12/14)

Off topic a little bit, but how do you measure the innitial yeast volume to work out starters?

I have been harvesting yeast and storing it in specimin containers from the local doctors supply (think the ones you pee in, there 60c each so IMO ideal). 

These are 75ml, but once its all said and done my "yeast" layer settles out to about a millimiter layer on the bottom, which some real rough maths tells me is probably around the 10ml mark. 

So do i go by the total 75ml volume and make a 500-750ml ish starter, or do i go by the rough yeast volume and make a 100ml starter for the first step?

If this has been covered feel free to tell me off but please point me in the right direction, only just got a stirplate/flasks etc so playing around atm. 

Cheers.


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## rude (2/1/15)

Ok I'm back again another yeast starter question sorry
I made my starter for a Kolsch brewed it & was very happy with the results one of the quickest yeast fire up ferments I've had
It was so tasty I want to brew it again
I have 6 pint stubbies of it bottled on the 14/12/14
So for my starter was going to pour beer off make a 300ml starter in the stubby then step up to a 1.5 Litre starter
then ferment out & pitch into a 1045 og wort
I've used yeast calc & put the manufactured date as the 14/12/14 ,hybrid yeast , stir plate Zainesheff .
What I'm worried about is the number of cells in the stubby , yeast calc is for packs or vials at 100billion cells
Using the method above with yeast calc I need 268 billion cells so for 300ml 118 bill then 1.5 L 300 bill at 83% viability
Should I be calculating yeast in the stubby at 50% viability or even less?
Should I just step up to 2 Litre starter or even bigger ?
Advice greatly appreciated cheers


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## elcarter (2/1/15)

Just my personal opinion but I'd only resort to reviving the bottle yeast if the yeast in that stubbie cant be economically purchased from a local brew store.

Feels like to much stuffing around and possible failure to make the $10-$12 saving worth it. 

Every time we've tired to re culture the Coopers pale ale yeast from the bottle it's giving us inconstant results every time. 

That said if your just bored and want to experiment then give it a try and see what you get.


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## rude (2/1/15)

No worries elcarter $16 for a smack pack here so if I squeezed another brew out of it that would be great
Inconsistency spose comes down to no way of knowing the number of cells & viability of the yeast in the stubbies
Will give it a try though treat it as 50% viability & will do a 2 Litre starter
Used to do the coopers stubbies ages ago but was underpitching then


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## solipsist (2/1/15)

TheWiggman said:


> This was my approach and I don't believe it's the right one. If the yeast gets exposed to a small quantity of wort it effectively gets 'trained' to that volume and become less and less suitable for full volume (when it's eventually pitched) the more you do it.


The only factor that could influence this is concentration of yeast. The yeast couldn't know or care what the full volume of starter is, so I can't see how they could become any more or less suitable for a particular volume. Everything I've read points to a few basic tips: 5x to 10x step up size for maximum growth in total number of yeast cells (good if you are not limited by container size), but as long as you are below 100mil cells / ml inoculation rate you aren't affecting yeast health by having smaller step up volumes. This same principle could be 100 bil cells in 1L, or 1 tril cells in 10L.


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