1 vs 2 Liter Starter

[smyrnaquince]

Starting with one packet of Wyeast yeast, what is the difference (is there a difference) between making a 2-liter starter and making a 1-liter starter, then stepping it up to 2 liters?

For the latter, I assume I can make a 1-liter starter, then a day later add a 2nd liter of wort.

Thanks!

 

[jmark]

As long as the yeast isn't too old (probably at least 50% viable) then you can do the full 2L volume at once without the intermediate step as the inoculation rate (millions of cells per milliliter of wort) is still reasonable enough to get the growth you want.

I use Homebrew Dad's yeast calculator for determining amounts to pitch... it's got features to allow calculations of multiple steps where needed:

http://www.brewunited.com/yeast_calculator.php

 

[Steveg229]

It all depends on the age of the yeast, the initial cell count, and the cell count that you are shooting for. Sometimes it is better just to make a 2L starter and sometimes it is better to step up in 1L increments. I use this http://www.brewunited.com/yeast_calculator.php to figure out starter size for each batch and to overbuild so I can harvest some for future batch.

 

[TheMadKing]

Yeast multiply to consume the available sugars. A 1 L starter will result in some growth, but less than a 2L starter. If you then step-up to a 2L starter you are pitching slightly more cells into the 2L starter than you would have straight from the smack pack. So again, you'll get less multiplication than pitching the smack pack directly into the 2L starter, but your overall cell count might be slightly higher.

In summary, stepping up a 1L starter to 2L is a waste of time IMHO since you'll only get slightly more cells and it's twice the work and twice the time.

If you want more cells, pitch into the largest starter size you can support. If you need even more than that, divide the slurry from the first starter in half, and pitch half of it into the same sized starter again.

The only thing to really avoid is making the yeast multiply by more than 10x in a single step. So if you have a very small starting cell count, you should make sure your cell count isn't going to increase by 10x by using smaller step-starters.

 

[smyrnaquince]

Yeast multiply to consume the available sugars. A 1 L starter will result in some growth, but less than a 2L starter. If you then step-up to a 2L starter you are pitching slightly more cells into the 2L starter than you would have straight from the smack pack. So again, you'll get less multiplication than pitching the smack pack directly into the 2L starter, but your overall cell count might be slightly higher.

In summary, stepping up a 1L starter to 2L is a waste of time IMHO since you'll only get slightly more cells and it's twice the work and twice the time.

If you want more cells, pitch into the largest starter size you can support. If you need even more than that, divide the slurry from the first starter in half, and pitch half of it into the same sized starter again.

The only thing to really avoid is making the yeast multiply by more than 10x in a single step. So if you have a very small starting cell count, you should make sure your cell count isn't going to increase by 10x by using smaller step-starters.

Thanks!

It does seem to me that the final cell count would be the same either way.

What is the reason for not exceeding 10x cell count increase? I'm having a hard time understanding the difference between putting the yeast into a large feedlot/swimming pool than starting them off in a smaller one first.

P.S. Where was your avatar picture taken?

 

[TheMadKing]

Thanks!

It does seem to me that the final cell count would be the same either way.

What is the reason for not exceeding 10x cell count increase? I'm having a hard time understanding the difference between putting the yeast into a large feedlot/swimming pool than starting them off in a smaller one first.

P.S. Where was your avatar picture taken?

That was on the side of Mt. Rainier in Washington (where I was born and raised).

Every time a yeast cell buds, it's cell wall thickness is reduced. So if it is forced to multiply a huge number of times before beginning true fermentation, you get weaker more sickly cells.

So each time you pitch your healthy cells into fresh wort of the proper gravity (1.040) and volume, you end up with the proper number of healthy cells needed to consume the sugars in the wort without stressing their cell walls too much.

 

[smyrnaquince]

Makes sense. Thanks.

Rainier--nice!

 

[kh54s10]

I don't think you get the same cell growth from a second addition as the first.

To know how much you need, use a calculator. A 1 liter starter and an addition of 2 more liters would be way more yeast than you need for most ales.... And would be a waste of money and DME.

I use this calculator:http://www.yeastcalculator.com/

 

[smyrnaquince]

I don't think you get the same cell growth from a second addition as the first.

I'd like to understand why this is not the case.

A 1 liter starter and an addition of 2 more liters would be way more yeast than you need for most ales.... And would be a waste of money and DME.

I asked about the difference if I make a 2-liter starter or if I "make a 1-liter starter, then a day later add a 2nd liter of wort". The second option gives a total of 2 liters; it is not a 1-liter starter, then the addition of 2 more liters.

 

[Steveg229]

I'd like to understand why this is not the case.



I asked about the difference if I make a 2-liter starter or if I "make a 1-liter starter, then a day later add a 2nd liter of wort". The second option gives a total of 2 liters; it is not a 1-liter starter, then the addition of 2 more liters.

This is correct. When you feed "X" amount of yeast cells a 1 liter starter, they multiply enough times to consume all of the sugar in the 1 liter. Now if you add another 1 liter starter you already have enough yeast to consume that 1 liter, so the need to multiply is substantially lower, resulting in least yeast growth.

If you take "X" amount of yeast and pitch into a 2 liter starter, they will multiply enough to consume that whole 2 liters.

 

[kh54s10]

I'd like to understand why this is not the case.



I asked about the difference if I make a 2-liter starter or if I "make a 1-liter starter, then a day later add a 2nd liter of wort". The second option gives a total of 2 liters; it is not a 1-liter starter, then the addition of 2 more liters.

I don't know but with the calculator I linked if you did a 1 liter then another one it gives different growth factors. The authors of thedifferent equations for methods of aeration are highly respected.

For the second part, sorry, I misread the amounts.

Answer to the original: Why mess around with 2 one liter starters when you can do a two liter starter? When I do stepped starters it is because I am starting with a very small quantity of yeast, old yeast or the size of the total is bigger than my flask. I freeze small yeast samples with glycerin/water mixture. When I make a starter for those I make a 250 ml initial starter of 1.020 wort. Then step up the size and gravity. I use the calculator linked.

 

[Denny]

I have moved past yeast calculators and stir plates. I now make a 1 qt. SNS start for almost all my beers and it works great. Faster and easier, too. https://www.experimentalbrew.com/blogs/denny/old-dognew-tricks

 

[smyrnaquince]

But how do you know if a 1-quart starter is big enough?

 

[Denny]

But how do you know if a 1-quart starter is big enough?

It is....that's the point. If the beer is big (>1.080) I'll do 2 qt. But I've successfully used the method on ales up to 1.076 and lagers up to 1.060.

 

[kh54s10]

I have moved past yeast calculators and stir plates. I now make a 1 qt. SNS start for almost all my beers and it works great. Faster and easier, too. https://www.experimentalbrew.com/blogs/denny/old-dognew-tricks

Have you done any side by side tests since 2015?

I think I would still prefer using the stirplate so that I didn't have to think about shaking. I could still pitch at high krausen.

 

[Dcpcooks]

Get the yeast book, it breaks it all down for you!

View attachment ImageUploadedByHome Brew1485992794.530899.jpg

 

[Dcpcooks]

Here is the another look, number of packs is in the middle. View attachment ImageUploadedByHome Brew1485993125.086837.jpg

 

[MerlinWerks]

Have you done any side by side tests since 2015?

I think I would still prefer using the stirplate so that I didn't have to think about shaking. I could still pitch at high krausen.

Look at the forum post linked at the end of Denny's article for a detailed explanation of the SNS starter. I believe the shaking part is meant to be a low tech way to initially oxygenate the starter wort, after that no shaking required. I don't mind a little tech so I skip the shaking and hit the starter wort with O2 at .5 LPM for about 30 seconds...

 

[kh54s10]

Look at the forum post linked at the end of Denny's article for a detailed explanation of the SNS starter. I believe the shaking part is meant to be a low tech way to initially oxygenate the starter wort, after that no shaking required. I don't mind a little tech so I skip the shaking and hit the starter wort with O2 at .5 LPM for about 30 seconds...

I see. Shaken usually means shake it up every time you pass by.....

 

[Denny]

Have you done any side by side tests since 2015?

I think I would still prefer using the stirplate so that I didn't have to think about shaking. I could still pitch at high krausen.

Yep. Still of the same opinion. I pitched a 1 qt. SNS starter into a 1.080 beer yesterday about 3 PM at 63F (WY1762 Abbey II) and by 6 this AM it was blowing off.

 

[Denny]

I see. Shaken usually means shake it up every time you pass by.....

Not this method...read the article and link.

 

[kh54s10]

Not this method...read the article and link.

I missed the link at the end that described the shake till it is mostly foam.

I will certainly give this a try.

 

[Denny]

I missed the link at the end that described the shake till it is mostly foam.

I will certainly give this a try.

You kind of have to suspend your disbelief..at least I did. We've all had it so ingrained that you need calculators and stir plates that sometimes you just have to try it yourself and do what works!

 

[kh54s10]

You kind of have to suspend your disbelief..at least I did. We've all had it so ingrained that you need calculators and stir plates that sometimes you just have to try it yourself and do what works!

If you have done this and it gets your approval that is all the convincing I need.

I just missed the part about how the shaking is done.

I am at a standstill at the moment. Anticipating a relocation. When settled I am going to do this method.


I have frozen samples of 5 ml yeast in 5 ml glycerin and 10 ml water. Do you have any suggestions on how to start those with this method?

 

[jmark]

What are thoughts as to WHY this works? Is it because the yeast gets so dispersed across all the surface area that there's less 'localized' competition when pitched? Forgive me if I missed that in the AHA thread.

 

[TheMadKing]

It works because it aerates the starter thoroughly, just like a stir plate would. In wort, oxygen is usually the limiting growth factor as opposed to sugar or mineral nutrients.

I don't see the advantage of the shake method over doing a vitality starter on a stir plate.

 

[IslandLizard]

It works because it aerates the starter thoroughly, just like a stir plate would. In wort, oxygen is usually the limiting growth factor as opposed to sugar or mineral nutrients.

I don't see the advantage of the shake method over doing a vitality starter on a stir plate.

I wonder if there's there any research on yeast propagation by just oxygenating 1 to 2 liter of starter with pure O2 to say 20-40 ppm and let it stand. Perhaps repeat every hour? I guess it should not be shaken or stirred, or you'll lose the O2 to the atmosphere.

 

[jmark]

It works because it aerates the starter thoroughly, just like a stir plate would. In wort, oxygen is usually the limiting growth factor as opposed to sugar or mineral nutrients.

I don't see the advantage of the shake method over doing a vitality starter on a stir plate.

I don't get this... so shaking and then pitching immediately (which is what I thought was happening here) wouldn't have any bearing on growth... it's not like the yeast miraculously grows exponentially in that few minutes between shaking and pitching? Maybe I'm missing something?

 

[TheMadKing]

I don't get this... so shaking and then pitching immediately (which is what I thought was happening here) wouldn't have any bearing on growth... it's not like the yeast miraculously grows exponentially in that few minutes between shaking and pitching? Maybe I'm missing something?

I don't think he's shaking and pitching immediately. And no the yeast is certainly not multiplying instantly.

A vitality starter refers to giving the yeast a few hours on a stir plate before pitching, and you can get away with a lower cell count because you're pitching yeast with full oxygen reserves that are already awake and ready to roll.

There's been little actual scientific studies of this method, but anecdotally it does seem to result in a shorter lag phase and no ill effects on the beer.

 

[TheMadKing]

I wonder if there's there any research on yeast propagation by just oxygenating 1 to 2 liter of starter with pure O2 to say 20-40 ppm and let it stand. Perhaps repeat every hour? I guess it should not be shaken or stirred, or you'll lose the O2 to the atmosphere.

It's not exactly a rigorous study, but a pro-brewer friend of mine says that he leaves an oxygen stone bubbling in his starter while it's on a stir plate for the entire duration and he claims that he gets 1.5-2x more cells from the same volume of starter wort.

 

[jmark]

I don't think he's shaking and pitching immediately. And no the yeast is certainly not multiplying instantly.

A vitality starter refers to giving the yeast a few hours on a stir plate before pitching, and you can get away with a lower cell count because you're pitching yeast with full oxygen reserves that are already awake and ready to roll.

There's been little actual scientific studies of this method, but anecdotally it does seem to result in a shorter lag phase and no ill effects on the beer.

Thanks - that makes sense... I obviously completely misread Denny's article, but going through that AHA thread again helped. I'm still more comfortable using my regular starter method as I usually overbuild my starters so that I have some extra yeast to build up the next batch' starter and I'm not sure this approach is conducive. That being said, when I'm not overbuilding, it's nice to know there's another option!

 

[Denny]

If you have done this and it gets your approval that is all the convincing I need.

I just missed the part about how the shaking is done.

I am at a standstill at the moment. Anticipating a relocation. When settled I am going to do this method.


I have frozen samples of 5 ml yeast in 5 ml glycerin and 10 ml water. Do you have any suggestions on how to start those with this method?

Boy, that's a tough one....I think you'd need to prop them up to the 100b cell range, then do the SNS starter.

 

[Denny]

What are thoughts as to WHY this works? Is it because the yeast gets so dispersed across all the surface area that there's less 'localized' competition when pitched? Forgive me if I missed that in the AHA thread.

Just a SWAG, but I'd say that there is so much oxygen on there due to the shaking that you get plenty of cell growth. In addition, not using a stir plate means you get no cell shear so the yeast is healthier.

 

[Denny]

It works because it aerates the starter thoroughly, just like a stir plate would. In wort, oxygen is usually the limiting growth factor as opposed to sugar or mineral nutrients.

I don't see the advantage of the shake method over doing a vitality starter on a stir plate.

For me it's a little easier. And theoretically at least, you get healthier yeast by not using a stir plate.

 

[Denny]

I don't get this... so shaking and then pitching immediately (which is what I thought was happening here) wouldn't have any bearing on growth... it's not like the yeast miraculously grows exponentially in that few minutes between shaking and pitching? Maybe I'm missing something?

No, you wait 24 hours and pitch at high krausen. Or close to it...doesn't seem to make a lot of difference.

 

[TheMadKing]

For me it's a little easier. And theoretically at least, you get healthier yeast by not using a stir plate.

I don't understand, how does using a stir plate harm the yeast?

Edit: Ah cell shear, I didn't see that earlier post at first.

"Cell shear is an issue with bacteria which have weaker cell walls than yeast. So when culturing bacteria in the lab they use a shaker table instead of a stir plate. Yeast also have a much higher demand for oxygen than bacteria and the stir plate is more effective at maintaining dissolved O2 levels. So, yes, cell shear does exist and it can theoretically happen to yeast, but you would need to be running an insanely powerful stir plate for it to affect your cell counts in any measurable sense. They wouldn't use stir plates in professional yeast growth if it was killing their cells, since other options are available."

-just asked microbiologist SWMBO and that was her reply.

 

[kh54s10]

Boy, that's a tough one....I think you'd need to prop them up to the 100b cell range, then do the SNS starter.

This looks like time for an Exbeeriment. Try the SNS with a weak wort for a step up then again for the pitch.

Or it is a traditional step up then a SNS starter.

I will have to look at this later in the year.

 

[Denny]

I don't understand, how does using a stir plate harm the yeast?

Edit: Ah cell shear, I didn't see that earlier post at first.

"Cell shear is an issue with bacteria which have weaker cell walls than yeast. So when culturing bacteria in the lab they use a shaker table instead of a stir plate. Yeast also have a much higher demand for oxygen than bacteria and the stir plate is more effective at maintaining dissolved O2 levels. So, yes, cell shear does exist and it can theoretically happen to yeast, but you would need to be running an insanely powerful stir plate for it to affect your cell counts in any measurable sense. They wouldn't use stir plates in professional yeast growth if it was killing their cells, since other options are available."

-just asked microbiologist SWMBO and that was her reply.

Well, research has shown that shear does occur at the homebrew level, but I don't know how much of a concern it really is. Yeast manufacturers use shaker tables. I can tell you that I used to use a stir plate for many years and still would if the results were better than the SNS method.

 

[TheMadKing]

Well, research has shown that shear does occur at the homebrew level, but I don't know how much of a concern it really is. Yeast manufacturers use shaker tables. I can tell you that I used to use a stir plate for many years and still would if the results were better than the SNS method.

http://webpages.mcgill.ca/staff/deptshare/FAES/066-Bioresource/Theses/theses/264BarryvanBergen2001/264BarryvanBergen2001.pdf

you got me curious, tons of really interesting info in here, even if it's a long read. One in particular, you can judge yeast slurry viability through pH measurement. If it's above 4.6 don't pitch it.

 

[masaba]

This looks like time for an Exbeeriment. Try the SNS with a weak wort for a step up then again for the pitch.

Or it is a traditional step up then a SNS starter.

I will have to look at this later in the year.

They have done something similar (twice) and it failed to show any difference either time.

http://brulosophy.com/2016/08/15/ye...ility-starter-in-a-lager-exbeeriment-results/

http://brulosophy.com/2015/06/29/ye...e-cell-count-vs-vitality-exbeeriment-results/

Of course, even their exbeeriment where they compared a starter to a single vial of white labs into a 1.063 beer failed to show significance. I'm of the belief that the yeasts nowadays are high enough quality that there is a lot of wiggle room here, but with that said, I still always make a starter.