Starters

[wepeeler]

So, to make my starters I've been using online calculators for the past 5 years. Most seem to be in agreement with one another. As long as you enter in yeast dates, an OG, a batch size and a starter L size, it spits out how much DME to start with. I just finished reading Chris White's Yeast book, and the information is definitely conflicting. I would trust Chris over most online calculators, but without counting cells, which I'm not doing, I can't be certain.

Basically the general idea from the book says it depends on initial pitch rate into the starter, NOT available sugar (DME). It stresses that the best way to start is with a 2L starter and build up with a multi-step approach. So essentially you start with 100 bil cells (ideally) and with a 2L starter and 200g DME, you'll have a total 205 bil cells in 24 hours - 105 bil new cells. Then cold crash, decant, add 2L new wort and the next step gets you an additional 100 bil new cells, not another 200 bil. So it's not linear.

When I brew a big ale, the online calculators have been telling me to make a 4-4.5L starter from a single vial to get to the 450 bil or so cells. According to the book, if you pitch a single 100 bil pack into a 4L starter you don't get to 450 bil or so. It's MUCH less than that. It's only 276 bil cells! (This is without agitation. I use a stir plate which dramatically increases growth by giving the yeast a constant supply of new oxygen. So maybe the stir plate is the answer!

*Edited - Seems as though the online calculators factor in agitation via a stir plate. I didn't think of that. More on the White Labs test below.

 

[wepeeler]

Just got home and re-read the starter section of Yeast. Looking at the table, White Labs ran a test pitching 100 bil cells into different size starters. Starting at 0.5L all the way up to 20L. 1L results in 52 bil new cells, 152 bil total. A 2L starter produces 105 bil new cells, effectively doubling to a total of 205 bil cells. Jumping up to a 4L starter (which I've been making for my neipas) the growth rate declines and only produces 176 bil new cells with a total of 276 bil cells. In order to get 400 bil cells, one would need to build an 8L starter from the initial 100 bil cells. That's obviously not ideal for the average homebrewer. There's another chart on the next page that shows how many packets of 100 bil cells you'd have to pitch in X size starter in order to get X number of cells. Looks like 2 100 bil packs would need to be pitched in a 4L starter to get 400 bil cells. White Labs also claims each yeast strain grows differently.

Wonder why online calculators don't use this information? If I trust the book, I'm wildly underpitching, and I should step up starters, or pitch more yeast into the 4L starter. This is especially important when brewing lagers!

Stir plates!!!

Food for thought, in case anyone was interested.

 

[hottpeper13]

When I step up my starters I do by the 10x method. That is 1- 15 ml wort sterile tube, 2- 150 ml flask, 3 -1500 ml flask. That is always enough yeast for a small beer of 1.040- 1.050. The yeast cake from the small beer then ferments the big beer. You get a beer you can drink while the big beer ages and you don't decant(waste) anything.

Have you used Brew Dad's calculator? It has step options and you can change the cell count if you do overbuild starters and save the yeast.

 

[CascadesBrewer]

Wonder why online calculators don't use this information?

What online calculator are you using? Give this one a try: Homebrew Dad's Online Yeast Starter Calculator

Your post is a bit confusing. How large of batch and what gravity of batch do you think requires an 8L starter?

Personally, if I need to get to the 400B cell range I either 1) use 2 packs of dry yeast or 2) make a smaller beer and pitch harvested yeast. In theory the entire yeast cake of a 2.5 gallon batch or half the yeast cake from a 5 gallon batch should be in the 400B cell range.

 

[wepeeler]

When I step up my starters I do by the 10x method. That is 1- 15 ml wort sterile tube, 2- 150 ml flask, 3 -1500 ml flask. That is always enough yeast for a small beer of 1.040- 1.050. The yeast cake from the small beer then ferments the big beer. You get a beer you can drink while the big beer ages and you don't decant(waste) anything.

Have you used Brew Dad's calculator? It has step options and you can change the cell count if you do overbuild starters and save the yeast.

That's the one I use. I've had to step up a few starters. Much easier making larger starters now that I have a 5L flask.

What online calculator are you using? Give this one a try: Homebrew Dad's Online Yeast Starter Calculator

Your post is a bit confusing. How large of batch and what gravity of batch do you think requires an 8L starter?

Personally, if I need to get to the 400B cell range I either 1) use 2 packs of dry yeast or 2) make a smaller beer and pitch harvested yeast. In theory the entire yeast cake of a 2.5 gallon batch or half the yeast cake from a 5 gallon batch should be in the 400B cell range.

That's the calculator I use. Seems pretty straightforward, and I've also been in contact with the guy who runs the site. Very nice guy and very eager to help. (He used to post here awhile back.)

I only mentioned the 8L starter in regards to building up proper cell count, directly from the book. I failed to mention the test was done without agitation so growth was limited. 1 100 bil pack resulted in 400 total cells (300 new) in an 8L starter. No one is doing that. Without adding oxygen, either directly or via a stir plate, the max number of new cells is greatly limited. The addition of a stir plate is most likely the reason we can make 300 bil new cells in a 4L starter. Most people do a 2L starter, but a lot of my beers are over 1.070. Obviously I go smaller when I make lower gravity beer. 2L for a 1.048 OG is fine.

Another thing the book mentions is that a lower cell count of healthy yeast is much better than the proper amount of sluggish yeast. So underpitching with a healthy culture is most likely ok, at least on the homebrew level.

 

[McMullan]

make a smaller beer and pitch harvested yeast.

Excellent strategy vs wasting 8L. Half a batch (12L) of beer. A win-win. I brew my Milds this way for this very reason.

 

[McMullan]

I use a stir plate which dramatically increases growth by giving the yeast a constant supply of new oxygen.

A stir plate isn't very good for oxygenating starter wort. You might get better results if you oxygenate the wort before stirring. Ideally with pure O2, if you use it. Shake vigorously if not. The main benefit of the stir plate is it keeps yeast cells in suspension where they get a better supply of nutrients for growth. Just enough RPM to prevent any yeast sedimenting on the bottom of the vessel therefore losing free access to nutrients, like in a basic 'set and forget' starter.

 

[Shenanigans]

[QUOTE="wepeeler, post: 9179935, member: 255654"
Another thing the book mentions is that a lower cell count of healthy yeast is much better than the proper amount of sluggish yeast. So underpitching with a healthy culture is most likely ok, at least on the homebrew level.
[/QUOTE]

I`d agree with this.

Mostly I´m making a starter from yeast harvested from a previous batch up to a few months before or sometimes from a new pack.
I never really get hung up on the numbers, I just want to check the vibility and give it a bit of a head start.

I'm sure I'd get stessed if I did all the calculations and in the end they would be just rough estimations anyway

I just wait until there is good activity and visibly a lot more yeast thanI started with and then pitch it.
Normally im at this stage after 3 days and have 500 to 1000ml liquid.
If the yeast has dropped clear then I decant off some of the liquid before shaking and adding.

Not saying what I do is best practice but is most convenient for me and seems to work fine.

 

[wepeeler]

A stir plate isn't very good for oxygenating starter wort. You might get better results if you oxygenate the wort before stirring. Ideally with pure O2, if you use it. Shake vigorously if not. The main benefit of the stir plate is it keeps yeast cells in suspension where they get a better supply of nutrients for growth. Just enough RPM to prevent any yeast sedimenting on the bottom of the vessel therefore losing free access to nutrients, like in a basic 'set and forget' starter.

The motion of the stir plate is constantly sucking air into the flask though. It's not pure oxygen, but it's continuously providing the yeast more oxygen. Yeast consumes all the available oxygen within 30 minutes of inoculation, so even a burst at the start is only so good. You want aerobic fermentation for growth. Anaerobic causes you to make beer, instead of focusing on growth.

 

[McMullan]

The motion of the stir plate is constantly sucking air into the flask though. It's not pure oxygen, but it's continuously providing the yeast more oxygen. Yeast consumes all the available oxygen within 30 minutes of inoculation, so even a burst at the start is only so good. You want aerobic fermentation for growth. Anaerobic causes you to make beer, instead of focusing on growth.

I see.

 

[Noob_Brewer]

@wepeeler I don't have the yeast book but were all those white lab tests you mentioned in your second post run with no agitation?

 

[wepeeler]

@wepeeler I don't have the yeast book but were all those white lab tests you mentioned in your second post run with no agitation?

Yes. I failed to mention that until after I posted and brainstormed some more. I re-read the starter part of the book and had a derp moment.

 

[Noob_Brewer]

SO Ive used both brewers friend and brew united online calculators for making my starters and it seems that if you assume that yeast are 100% viable at the time of making the starter and starting with 100B cells, for a 2L starter with ~200g DME and "no agitation" selected, the calculators would give you 208b cells (brewers friend) and 179b cells (brew united). So I think these are within the range of what the White Labs tests you posted. I am assuming that the white lab tests actually counted the cells for these benchmark tests, whereas the software calcs model the total cell count based on formulas from others (braukeiser and/or white). Would have been great if white labs re-ran these benchmark tests and used agitation ie stir plate though.

 

[wepeeler]

I agree 100%. The book was written in 2010, so there has definitely been strides of progress made since then. I know the science is sound, but practices may have evolved a bit. The stir plate is huge in getting a constant flow of oxygen into the starter, therefore helping growth occur, not just fermentation. Would be very interesting to see a revamped test!

 

[McMullan]

The stir plate is huge in getting a constant flow of oxygen into the starter

Where did you get that idea from?

Without controlled airflow into a vessel the oxygen transfer rate to liquid media is going to be very inefficient and unlikely to reach a concentration sufficient to support much biomass increase. This might explain why you need to use an 8L 'starter' to get enough cells to pitch. And you're probably under pitching your starter wort therefore pushing the process towards fermention rather than culturing biomass/yeast cells. This isn't explained very well in White & Zainasheff's book, but, to be fair, it can be very difficult to anticipate how different readers are going to interpret what you write. Regardless of a vortex, the turbulence it promotes at a liquid's surface, it's going to have minimal effect on rate of oxygen transfer at the air-liquid interface, unless the air/O2 level inside the vessel is continuously replaced by managing the airflow.

If you begin with starter wort that has sufficient dissolved O2, before pitching enough healthy yeast cells, you'll be able to culture enough cells in much smaller volumes of wort, even if you leave it on a countertop and forget about it for several days.

 

[hottpeper13]

With the Homebrew Dads calculator you can play with most of the imputs. So I put in values for a step starter where the first step was 1.5 L on a stir plate. The second was a 20 L static. What I noticed was that when you pitch less then the 10x method the multipul is like 1.5 - 2 times. You want 3-5 times for having very viable yeast,so doing a 1.5 L and decanting then adding another 1.5 L is not making healthy yeast.
I sometimes (more then not) thak my staeter no mater what size and decant it on brew day then take a qt of wort after 10 min boil ,chill and pitch onto starter, let get to high krausen then pitch the whole thing. Guaranteed to be going in 4-8 hrs.

 

[wepeeler]

Where did you get that idea from?

Without controlled airflow into a vessel the oxygen transfer rate to liquid media is going to be very inefficient and unlikely to reach a concentration sufficient to support much biomass increase. This might explain why you need to use an 8L 'starter' to get enough cells to pitch. And you're probably under pitching your starter wort therefore pushing the process towards fermention rather than culturing biomass/yeast cells. This isn't explained very well in White & Zainasheff's book, but, to be fair, it can be very difficult to anticipate how different readers are going to interpret what you write. Regardless of a vortex, the turbulence it promotes at a liquid's surface, it's going to have minimal effect on rate of oxygen transfer at the air-liquid interface, unless the air/O2 level inside the vessel is continuously replaced by managing the airflow.

If you begin with starter wort that has sufficient dissolved O2, before pitching enough healthy yeast cells, you'll be able to culture enough cells in much smaller volumes of wort, even if you leave it on a countertop and forget about it for several days.

I thought the book explained it very well. The stir plate is sucking in air, even if it's an inefficient transfer. CO2 out, O2 in. They even offered the idea that some people do this in plastic soda bottles without stir plates. Vent it every few hours, squeeze the bottle to push out CO2 and release to suck in O2. Definitely not the most efficient way. Chris even said, without lab control, it would be impossible to grow yeast the way they do. Leaving a starter on a counter without any type of agitation is the least effective way to grow yeast, as shown by the test they did.

It's the same reason you keep your fermentor sealed. Oxygen ingress. It's not the same as direct injection via pure O2, but it provides the yeast with enough constant oxygen to promote growth not just ferment to make beer. Yeast consume all available oxygen within 30 minutes of pitching (which is incredible!), so unless you have a constant flow of O2 into the vessel, they start anaerobic fermentation, and begin to make beer, not just grow.

 

[McMullan]

I thought the book explained it very well. The stir plate is sucking in air, even if it's an inefficient transfer. CO2 out, O2 in. They even offered the idea that some people do this in plastic soda bottles without stir plates. Vent it every few hours, squeeze the bottle to push out CO2 and release to suck in O2. Definitely not the most efficient way. Chris even said, without lab control, it would be impossible to grow yeast the way they do. Leaving a starter on a counter without any type of agitation is the least effective way to grow yeast, as shown by the test they did.

It's the same reason you keep your fermentor sealed. Oxygen ingress. It's not the same as direct injection via pure O2, but it provides the yeast with enough constant oxygen to promote growth not just ferment to make beer. Yeast consume all available oxygen within 30 minutes of pitching (which is incredible!), so unless you have a constant flow of O2 into the vessel, they start anaerobic fermentation, and begin to make beer, not just grow.

Mmm! It’s a bit difficult to explain things well when they’re wrong, to be fair. That’s what I’ve always thought anyway. Ask anyone who’s actually worked with bioreactors in labs and pilot plants. If a lot of what you claim is actually published in White & Zainasheff’s book (I didn't read much of my copy) then either it wasn’t reviewed properly, by someone who had a clue, which was my initial impression, or they were exercising some kind of ‘artistic licence’ so as not to complicate issues for home brewers at the time of publication. I think home brewers have willingly complicated their lives since then and many have upped their games considerably. Honestly, I think it’s excellent.

It’s not so much that O2 promotes (aerobic) respiration as it is glucose concentrations greater than about 1% (w/v) promote fermentation, regardless of O2 levels. Sure, a lot of cells are going to be expressing 'respiration' traits under O2 conditions, but here’s why. The fact O2 is toxic to living cells is the reason why O2 gets removed so quickly. Less than 40% or so goes into potential biomass. Presumably what’s left is what cells can process by other means within about 30 minutes or so, to render the oxygen ‘safe’. Yeast evolved eons ago, before oxygen polluted the primordial atmosphere. For a long time it was assumed fermentation was less efficient (in terms of producing cellular energy) than respiration, but actually, at least for yeast, fermentation is actually more efficient because the ‘cost’ charged by the proteome to ferment is much lower. Clever little f*ckers really.

As far as experiments go, generally, (not to be confused with Brülosophy's opinions!) it’s very important to appreciate that they are always limited by their design and procedures. That’s not to say they’re wrong, far from it; just that they hold 'true' under the conditions they were conducted in, hopefully. So, for example, in the experiments I run, a different design is used with a different set of procedures and although the same general pattern is observed, my starter left on the countertop for several days might actually finish with a higher cell count than someone else’s stirred starters, including White & Zainasheff’s.

I hope this opens your mind to improve your brewing practices therefore your beers.

Cheers!

 

[wepeeler]

Mmm! It’s a bit difficult to explain things well when they’re wrong, to be fair. That’s what I’ve always thought anyway. Ask anyone who’s actually worked with bioreactors in labs and pilot plants. If a lot of what you claim is actually published in White & Zainasheff’s book (I didn't read much of my copy) then either it wasn’t reviewed properly, by someone who had a clue, which was my initial impression, or they were exercising some kind of ‘artistic licence’ so as not to complicate issues for home brewers at the time of publication. I think home brewers have willingly complicated their lives since then and many have upped their games considerably. Honestly, I think it’s excellent.

It’s not so much that O2 promotes (aerobic) respiration as it is glucose concentrations greater than about 1% (w/v) promote fermentation, regardless of O2 levels. Sure, a lot of cells are going to be expressing 'respiration' traits under O2 conditions, but here’s why. The fact O2 is toxic to living cells is the reason why O2 gets removed so quickly. Less than 40% or so goes into potential biomass. Presumably what’s left is what cells can process by other means within about 30 minutes or so, to render the oxygen ‘safe’. Yeast evolved eons ago, before oxygen polluted the primordial atmosphere. For a long time it was assumed fermentation was less efficient (in terms of producing cellular energy) than respiration, but actually, at least for yeast, fermentation is actually more efficient because the ‘cost’ charged by the proteome to ferment is much lower. Clever little f*ckers really.

As far as experiments go, generally, (not to be confused with Brülosophy's opinions!) it’s very important to appreciate that they are always limited by their design and procedures. That’s not to say they’re wrong, far from it; just that they hold 'true' under the conditions they were conducted in, hopefully. So, for example, in the experiments I run, a different design is used with a different set of procedures and although the same general pattern is observed, my starter left on the countertop for several days might actually finish with a higher cell count than someone else’s stirred starters, including White & Zainasheff’s.

I hope this opens your mind to improve your brewing practices therefore your beers.

Cheers!

Yeast is a bunch of clever little f*uckers! Lol.

Let me back up a touch. I posted my OP because I knew I was missing something. I couldn't understand the difference between the starter information in the book vs online calculators. After having my own ah-ha moment, I realized the difference was the stir plate. I understand it's not the most efficient way of introducing oxygen to the starter, but it's better than just letting it sit on a countertop. Makes sense, as this information is also a variable on any online calculator. ie Homebrew Dad's Online Yeast Starter Calculator Stir plate vs no stir plate = dramatic difference in final cell count.

I understand what you're saying. I get that the homebrew community has evolved beyond the traditional scope of the early days. It's what makes us better! I'm try to keep an open mind in all aspects of life, as that's really the only way to improve! I just have a really hard time believing that Chris White (the founder of one of the largest yeast labs in the world) and his colleague Jamil Zainasheff (the Brewmaster and owner of Heretic Brewing Company) would have written the definitive yeast guide and be touting incorrect information. And if they were, why wouldn't there be advances in the science and someone calling them out? Chris made sure to explain in the book that even yeast of the same strain and cell number may act differently in 2 separate matching samples of wort. His test with making starters without agitation is telling. It's conclusion is that inoculation rate is the driving force behind growth rate. The same inoculation rate in different volume starters results in different growth factors. That was really my issue with my first post. I thought I was doing something wildly incorrect, and I wanted to see if someone could figure out what it was.

Thanks for the convo!

 

[McMullan]

Yeast is a bunch of clever little f*uckers! Lol.

Let me back up a touch. I posted my OP because I knew I was missing something. I couldn't understand the difference between the starter information in the book vs online calculators. After having my own ah-ha moment, I realized the difference was the stir plate. I understand it's not the most efficient way of introducing oxygen to the starter, but it's better than just letting it sit on a countertop. Makes sense, as this information is also a variable on any online calculator. ie Homebrew Dad's Online Yeast Starter Calculator Stir plate vs no stir plate = dramatic difference in final cell count.

I understand what you're saying. I get that the homebrew community has evolved beyond the traditional scope of the early days. It's what makes us better! I'm try to keep an open mind in all aspects of life, as that's really the only way to improve! I just have a really hard time believing that Chris White (the founder of one of the largest yeast labs in the world) and his colleague Jamil Zainasheff (the Brewmaster and owner of Heretic Brewing Company) would have written the definitive yeast guide and be touting incorrect information. And if they were, why wouldn't there be advances in the science and someone calling them out? Chris made sure to explain in the book that even yeast of the same strain and cell number may act differently in 2 separate matching samples of wort. His test with making starters without agitation is telling. It's conclusion is that inoculation rate is the driving force behind growth rate. The same inoculation rate in different volume starters results in different growth factors. That was really my issue with my first post. I thought I was doing something wildly incorrect, and I wanted to see if someone could figure out what it was.

Thanks for the convo!

I approach matters from a different angle, that's all. I'm not selling anything. I have the upmost respect for White Labs and Wyeast. They made big things happen for home brewers. So much so I wouldn't even consider entertaining copycat firms hoping to cash in. Leave it to the founders, I say. Running a successful business like White Labs on a global scale requires business acumen more than anything. I'm not criticising anyone on any level here. Just pointing out a little bit of what's not right in a static publication from tens years ago. I'd be very surprised if Chris White's views hadn't changed too. I know mine have. And I know that's a good thing. So there's no need to waste time being an apologist for anyone here. Plan your next brew with a fresh open mind. It might surprise you