Starter w/ two packs vs. step up

I'm trying to understand something a little bit better... I am getting ready to brew my first lager but I'm trying to gain a better understanding of how to approach my starter; 5.25 gallons of 1.055 lager wort requires ~400B cells. I used some hypothetical variables as I don't actually have any yeast in hand yet therefore, I don't know the date on it. However, I input the above data with a date of 12/8/2015 (completely arbitrary) and it gave me 2 vials in a 3.37 liter starter even with the slider to the far right.

If I jump over to Brewers Friend Yeast Calculator and input the exact same variables (using ProBrewer 1.5 as I assume Mr. Malty is using the same factor for lagers) and use Kai's growth model it seems that I can get to the same pitch rate with 1 vial in a ~2.5 liter starter. That is no problem as I have a 5 liter flask.

So, here are my three options as I see it:

1. Use 2 vials in a 3.37 liter starter
2. Use 1 vial in a ~2.5 liter starter
3. Step up my starter

Please note, I'm not looking for the easiest or cheapest way to accomplish this, I'm looking for the best way. With that in mind, which method is the most advantageous for a quality end result?

The one burning question I have...is there an absolute ceiling on the growth of one vial of yeast in a starter?

I am no expert on yeast, but to the question of a ceiling on the growth of 1 vial of yeast, I believe this would have to be infinite given the availability of food source and suitable conditions. I am basing this on the act you can effectively do a 5 Gal "starter" with 1 vial of yeast. We just tend to call this a batch.

That being said I am sure this is a super-oversimplified response and I'd be interested in the experts opinions.

The limiting factor for yeast growth is the cell density per unit volume. So the maximum size of your starter dictates the highest number of cells which you can grow.

This means that you cannot grow double the number of cells just by adding an extra pack of yeast to your starter. There are limits to yeast cell reproduction but as a general rule we homebrewers don't hit those. If you are hitting those limits you are likely already aware.

PeteNMA said:

The limiting factor for yeast growth is the cell density per unit volume. So the maximum size of your starter dictates the highest number of cells which you can grow.

This means that you cannot grow double the number of cells just by adding an extra pack of yeast to your starter. There are limits to yeast cell reproduction but as a general rule we homebrewers don't hit those. If you are hitting those limits you are likely already aware.

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I assume you're referring to quorum sensing?

Not sure how you calculated that you need 19 million cells per mL when general rule is 12 million per mL for a lager, which is easily achievable with a 2L starter and a single vial. Personally I don't dwell on these things and just pitch two dry yeast packs.

TheBigLebrewsk1 said:

Not sure how you calculated that you need 19 million cells per mL when general rule is 12 million per mL for a lager, which is easily achievable with a 2L starter and a single vial. Personally I don't dwell on these things and just pitch two dry yeast packs.

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Yes, Noonan mentions that pitching rate (12M/mL) but if you're cold pitching it's simply not enough yeast. In fact, it's barely a hybrid pitching rate. If you're making lagers the incorrect way (starting them at a high temp and lowering down to lagering range) this might be enough yeast but still probably not.

Now, you go on to say that you pitch 2 satchets (I'm assuming 11.5g) into your wort, that's over 400+B cells or a pitch rate of around 20M cells/mL. So, we're at the same spot.

If you anticipate brewing more lagers in the future, build or buy a stirplate. It makes a big difference in cell count vs. a simple starter or one that's swirled around every so often.

Ryat66 said:

2. Use 1 vial in a ~2.5 liter starter

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This. The limiting factor for yeast health/ideal growth is your pitch rate into the starter. You will get healthier yeast with a lower pitch rate into the starter to allow for additional growth. You want your initial cells per extract to be 1.5 Billion per gram or less, but lower than that is fine.

I regularly make 10 gallon lagers with one vial into 4.5L on a stir plate (~783billion cells | 1.52M/mL/P on a 1.055 lager).

Pitching additional vials limits your growth. Stepping up is a solution for having a flask that is too small, you don't have that problem--with out that, stepping up is just another opportunity for contamination.

Ryat66 said:

Yes, Noonan mentions that pitching rate (12M/mL) but if you're cold pitching it's simply not enough yeast. In fact, it's barely a hybrid pitching rate. If you're making lagers the incorrect way (starting them at a high temp and lowering down to lagering range) this might be enough yeast but still probably not.

Now, you go on to say that you pitch 2 satchets (I'm assuming 11.5g) into your wort, that's over 400+B cells or a pitch rate of around 20M cells/mL. So, we're at the same spot.

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Your rates are off.

Even wyeast says 10 million per mL on a cold pitch.

https://www.wyeastlab.com/com-pitch-rates.cfm

From experience 2 dry yeast packs eliminates the need for a starter or a single vial starter works as well. Pitching at room temp with a single vial works to. I use all three of these techniques as well as others I know that make copious amounts of lager, I made 6 batches in December and January, my friend has made 12 since this summer and they are all excellent except one pils I made with out of date yeast I bought on clearance.

BigFloyd said:

If you anticipate brewing more lagers in the future, build or buy a stirplate. It makes a big difference in cell count vs. a simple starter or one that's swirled around every so often.

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I should've mentioned in the original post that I do use a stir plate.

RoundKid said:

This. The limiting factor for yeast health/ideal growth is your pitch rate into the starter. You will get healthier yeast with a lower pitch rate into the starter to allow for additional growth. You want your initial cells per extract to be 1.5 Billion per gram or less, but lower than that is fine.

I regularly make 10 gallon lagers with one vial into 4.5L on a stir plate (~783billion cells | 1.52M/mL/P on a 1.055 lager).

Pitching additional vials limits your growth. Stepping up is a solution for having a flask that is too small, you don't have that problem--with out that, stepping up is just another opportunity for contamination.

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So, it looks like you do subscribe to Kai's growth model. I have been back and forth for quite some time between Kai's and Dr. Chris White's theories on growth. I want to believe Dr. White because of his experience and background but after reading Kai's study on growth on a stir plate, there's some very compelling conclusions

In any event, this is very helpful. Thank you!

Ryat66 said:

I should've mentioned in the original post that I do use a stir plate.

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According to research by Woodland Brews a stir plate gets you to the final amount of yeast quicker but does not increase the number of cells if you just wait longer.

http://www.woodlandbrew.com/2015/02/yeast-starters-stirred-vs-not.html

I also question the necessity of the big starter. Gordon Strong has said that he often makes a lager with a single smack pack, no starter involved. If he can make a good lager with so few cells, why do you feel that you have to have so many? Are you just not creating the conditions for yeast growth in your beer?

TheBigLebrewsk1 said:

You seem highly confused about making beer and pitch rates. Even wyeast says 10 million per mL on a cold pitch but you probably know more than the professional yeast manufacturer which is why I assume you are trolling on a message board. Read and learn.

https://www.wyeastlab.com/com-pitch-rates.cfm

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Whoa...**white flag**

The yeast knowledge I have comes straight from the Yeast book. So, when I talk about pitch rates it's verbatim what Dr. Chris White and Jamil have written. I've also read Kai's study on stir plate growth and respect that as well. Having said that, I started this thread looking for some opinions on the best way to get to where I need to be.

I'm not here to troll. Do I come across as a know it all on message boards? Probably. It's not intentional but I like to talk numbers; I am not a rule of thumb brewer.

Zainasheff uses conservative pitching rates (i.e., more cells), so I prefer to use his numbers. His rule of thumb is also pretty easy: 0.75 million cells/mL/°P for ales, double that for lagers. So for a 1.055 lager, that'd be roughly 14° P, so 1.5 million cells/mL * 19,000 mL * 14° P = 399 billion, or almost exactly what the OP stated in his first post. That's the number I'd use.

I'd make a 5L starter with 1 pack of liquid yeast and let it ride the stir plate. It's an overpitch, but with lagers, it's hard to really overpitch. I'd rather overpitch than underpitch.

kombat said:

Zainasheff uses conservative pitching rates (i.e., more cells), so I prefer to use his numbers. His rule of thumb is also pretty easy: 0.75 million cells/mL/°P for ales, double that for lagers. So for a 1.055 lager, that'd be roughly 14° P, so 1.5 million cells/mL * 19,000 mL * 14° P = 399 billion, or almost exactly what the OP stated in his first post. That's the number I'd use.

I'd make a 5L starter with 1 pack of liquid yeast and let it ride the stir plate. It's an overpitch, but with lagers, it's hard to really overpitch. I'd rather overpitch than underpitch.

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This is extremely helpful and exactly what I had bouncing around inside my head. Sometimes I just need some validation because I am relatively new to brewing, at least I feel like I am.

Next question...In your experience, how much does lager yeast foam up on the stir plate? I ask this because I am not a fan of using Fermcap-S unless absolutely necessary. While I am just dipping into lagers, I am somewhere around 25 ale batches and it seems like every strain behaves a little bit different on the stir plate. For instance, WLP001 (WY1056) foams up like crazy while WLP002 (WY1968) generates almost no foam. How do the lager strains behave?

I am just trying to get a sense of my maximum starter size in a 5L flask. Thoughts?

RM-MN said:

According to research by Woodland Brews a stir plate gets you to the final amount of yeast quicker but does not increase the number of cells if you just wait longer.

http://www.woodlandbrew.com/2015/02/yeast-starters-stirred-vs-not.html

I also question the necessity of the big starter. Gordon Strong has said that he often makes a lager with a single smack pack, no starter involved. If he can make a good lager with so few cells, why do you feel that you have to have so many? Are you just not creating the conditions for yeast growth in your beer?

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This is an interesting read, thank you for sharing.

I never use Fermcap-S with my starters. I've found that the action of the stir plate alone serves to prevent a fluffy krausen from foaming up and getting too out of control. That said, I usually only go to about 4000 mL in my 5000 mL flask. If I were to go all the way to 5000 mL (as I'm actually planning to do tonight or tomorrow night), I would probably take the insurance and just hit it with a couple drops of Fermcap-S, unless I was going to be around to keep an eye on it (I'm not).

kombat said:

I never use Fermcap-S with my starters. I've found that the action of the stir plate alone serves to prevent a fluffy krausen from foaming up and getting too out of control. That said, I usually only go to about 4000 mL in my 5000 mL flask. If I were to go all the way to 5000 mL (as I'm actually planning to do tonight or tomorrow night), I would probably take the insurance and just hit it with a couple drops of Fermcap-S, unless I was going to be around to keep an eye on it (I'm not).

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Thank you for the advice.

Ryat66 said:

Next question...In your experience, how much does lager yeast foam up on the stir plate?

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Not much when using the plate.