Pitching rate for Boho Pils

[The-Engineer-That-Brews]

Planning to brew a Bohemian Pilsner next week as my first attempt at a lager.
Slightly gobsmacked to read in this article on byo.com:

"You need around 400 billion clean, healthy cells to properly ferment 5 gallons (19 L) of this beer, which is double what you would use for an equivalent strength ale. For a simple, non-stirred starter, one package of liquid yeast in 2.3 gallons (8.7 L) will result in the right amount of yeast."

Did I read that right... an 8.7 litre starter in a 19 litre batch of beer?

Later on in the step-by-step recipe he says:

Chill the wort to 50 °F (10 °C) and aerate thoroughly. The proper pitch rate is 20 grams of properly rehydrated dry yeast, four packages of liquid yeast or one package of liquid yeast in a 9-liter starter. Ferment around 50 °F (10 °C) until the yeast drops clear.

I can't see anything in e.g. the GH recipe to suggest such a huge starter is needed - am I missing something here?

 

[Rochefort]

One pack of healthy yeast in a ~1.7 L starter is good enough (for ~230 bn cells). Even if you target 400 billion cells, that still only needs a 400/140 = 2.8 L starter culture.

I think a big part of the problem with the 'non-stirred' starter is the assumption that you get very low growth, which isn't true. It is slower and the yeast are less healthy/vital, but you eventually get the same number of cells per ml. 8.7 L is bonkers.

 

[foxbat]

Planning to brew a Bohemian Pilsner next week as my first attempt at a lager.
Slightly gobsmacked to read in this article on byo.com:



Did I read that right... an 8.7 litre starter in a 19 litre batch of beer?

Later on in the step-by-step recipe he says:



I can't see anything in e.g. the GH recipe to suggest such a huge starter is needed - am I missing something here?

Make sure you buy a pack that's as young as you can find based on age and initial cell count. 6 months BBE/100bn on Wyeast and White Labs pure-pitch. 4 months BBE/80bn cells in White labs vials. 5 months BBE/150bn on Omega yeast. 4 months BBE/200bn cells for Imperial yeast. If I'm fermenting cold and not overbuilding I aim for a 2 - 2.5 litre starter based on this calculator. Any bigger and you start getting into multi-stage starters which is a bit of a pain (I'm doing one now).

Or just buy dry lager yeast and pitch 2 packs.

 

[The-Engineer-That-Brews]

Thanks @foxbat @Rochefort ...
For what it’s worth I‘m using the WLP800 for this one - should arrive next week and the supplier says it’s best before 15 sept 2021 - not sure how old that makes it?
I‘ve got a magnetic stir plate, conical flasks of 500, 1000 and 2000ml and plenty of spray-malt; and I was planning to cold ferment at 10°C...
Any advice on the size of starter, how much DME to use and when to put it on would be very gratefully accepted!

 

[The-Engineer-That-Brews]

Make sure you buy a pack that's as young as you can find based on age and initial cell count. 6 months BBE/100bn on Wyeast and White Labs pure-pitch. 4 months BBE/80bn cells in White labs vials. 5 months BBE/150bn on Omega yeast. 4 months BBE/200bn cells for Imperial yeast. If I'm fermenting cold and not overbuilding I aim for a 2 - 2.5 litre starter based on this calculator. Any bigger and you start getting into multi-stage starters which is a bit of a pain (I'm doing one now).

Or just buy dry lager yeast and pitch 2 packs.

OK, that’s really useful info, thanks! I’m having a go with that calculator now - great link.
So with the WLP800, bbe 15 Sept I should have 80bn viable cells if I understand correctly?
What volume would you say is safe to do in a 2000ml flask... a litre?
Thanks in advance...

 

[foxbat]

OK, that’s really useful info, thanks! I’m having a go with that calculator now - great link.
So with the WLP800, bbe 15 Sept I should have 80bn viable cells if I understand correctly?
What volume would you say is safe to do in a 2000ml flask... a litre?
Thanks in advance...

Assuming it turns up in a pure-pitch sachet then use 100bn as the initial cell count and 15 March as the manufacturing date. A bottom-fermenting lager yeast generally won't try to volcano out of a flask but yes, a litre is a safe level. If you're going to be doing a lot of lagers then one of these is a good investment.

It's best to get overnight delivery on liquid yeasts, particularly in the summer. You want them out of the fridge for the least time possible.

 

[DocAnna]

I've spent ages building lager starters with a couple of my previous lagers but have most recently moved to multiple packs of dried CML Hell yeast which was a whole lot simpler.

Anna

 

[The-Engineer-That-Brews]

that’s a really good price on a 5l flask there @foxbat

heh - yes, I’ve built dozens of starters... for my sourdough!
First time I’ll have done one properly for my brewing though.

I‘ve used the WLP pure pitch before in ale, but not done a starter with it which is probably why my brews have sometimes got off to a slightly slow start. Every day’s a school day... brew beer, they said... it’s really simple, they said ... (I Iove it really)
I get my yeast from themaltmiller and they send it out DPD along with a cold pack in the box which seems to work well.
Soooo how long do you allow between steps, stirred, at 20deg? For bread yeast in active mode I‘d normally expect 5hrs or so...

 

[Brewnaldo]

I've spent ages building lager starters with a couple of my previous lagers but have most recently moved to multiple packs of dried CML Hell yeast which was a whole lot simpler.

Anna

And cheap as chips into the bargain. I'm considering trying MJ Cali lager yeast for my next brew but i've got more Hell than a Hellery so might stick for now

 

[Rochefort]

Soooo how long do you allow between steps, stirred, at 20deg? For bread yeast in active mode I‘d normally expect 5hrs or so...

At 20 C you are looking at maybe 3-4 hours for the number of cells to double up to a maximum density of 140-160 billion cells per litre.

For 1-in-10 steps I usually leave 14-16 hours to account for any lag phase and 3.5 doublings (3.5*4 = >14 hrs).

If you are adding 80 bn to 2 L the maximum cell count is going to be ~300 bn or just under 3 doublings and take a minimum of 12 hours.

 

[foxbat]

Soooo how long do you allow between steps, stirred, at 20deg? For bread yeast in active mode I‘d normally expect 5hrs or so...

@Rochefort has got the timings right. If you're stepping up by adding more wort to a big flask then no probs. If you're stuck with a small flask then multiple steps are going to take much longer because you'll need to let each step flocculate so you can decant off the spent wort to make space in your flask for the next step.... so buy that big flask!

 

[The-Engineer-That-Brews]

so buy that big flask!

The way this is going, I'll just do it in my spare fermenter

 

[The-Engineer-That-Brews]

OK...

So it looks like I need to target the cells from about 4L of starter, but I'll build in 1 litre quantities so as to keep the innoculation levels around the 50-100 million/ml mark.

I'm thinking of doing 15hr growth each day on the stirplate, then chilling overnight in the fridge to precipitate out the cells. Then I'll re-pitch the correct proportion of the sediment to repeat the following day, holding back the rest in the fridge until I've got built up enough of the little fellas (presumably they won't come to any harm for a few days in the fridge?).
The BrewUnited calculator is helpful but I'll have to play with it a bit to do a progressive build as it seems to be based on re-pitching all the cells each time.

One final question: as my wort is likely to have an OG of around 1050, should I propagate the yeast in the same kind of conditions? I remember reading somewhere that a sudden change in sugar concentrations can make the yeast cells rupture due to osmotic pressure... EDIT: this study on brauskiser seems to suggest that going over 10º Plato (s.g. 1.040) for the starter isn't advisable

 

[The-Engineer-That-Brews]

Here's the plan...

Does that look relatively sane please?

 

[The-Engineer-That-Brews]

Am I being stupid, or is the BrewUnited pitching calculator off-beam here...?

Surely a batch volume of 1 litre pitched at 1.5 million/ml is 15 Bn cells, not 19 Bn

 

[The-Engineer-That-Brews]

Interestingly, various xBmts on brulosophy (eg: this one) seem to indicate no flavour differences between quite significant amounts of ‘under’ and ‘over’ pitching ... however there is no doubt that the more highly-pitched brews consistently get off to a much faster start, and complete their fermentation sooner. Doubtless this reduces the chances of less desirable microorganisms getting a foothold too.

 

[foxbat]

Am I being stupid, or is the BrewUnited pitching calculator off-beam here...?

Surely a batch volume of 1 litre pitched at 1.5 million/ml is 15 Bn cells, not 19 Bn

View attachment 47076

There's a multiplier in there to account for your OG. Can't remember what it is per degree plato.

 

[foxbat]

Interestingly, various xBmts on brulosophy (eg: this one) seem to indicate no flavour differences between quite significant amounts of ‘under’ and ‘over’ pitching ... however there is no doubt that the more highly-pitched brews consistently get off to a much faster start, and complete their fermentation sooner. Doubtless this reduces the chances of less desirable microorganisms getting a foothold too.

Yes very true. Wyeast Labs tell us that ester production is directly proportional to pitch rate and that 2 packs, or a starter, are required to do a lager... and that's for US customers that get the packs within weeks of production.

 

[foxbat]

I'm thinking of doing 15hr growth each day on the stirplate, then chilling overnight in the fridge to precipitate out the cells. Then I'll re-pitch the correct proportion of the sediment to repeat the following day, holding back the rest in the fridge until I've got built up enough of the little fellas (presumably they won't come to any harm for a few days in the fridge?).
The BrewUnited calculator is helpful but I'll have to play with it a bit to do a progressive build as it seems to be based on re-pitching all the cells each time.

To be honest if I was doing a 23l batch and was stuck with a 2l flask and the pack of yeast that you have then I'd just do a 0.8 litre first stage starter, chill, decant, add a 1.4 second stage and call it close enough. 1.5 litres of lager yeast in a 2 litre flask shouldn't overflow.

 

[Northern_Brewer]

For what it’s worth I‘m using the WLP800 for this one - should arrive next week and the supplier says it’s best before 15 sept 2021 - not sure how old that makes it?

Just to confuse things further, WLP800 is a funny one, it's actually an ale yeast that gets sold for lager (conversely WLP051 is a lager yeast that gets sold as an ale yeast). And anecdotally it stays clean even at more "ale-y" temperatures, which would reduce the cell count needed to start with.