White labs vial - optimum step up conditions?

[jat147]

Howdy,
I want to use a white labs vial for a lager brew at about 250L/66Gal, and OG 1050.
With my ale brews, I always use a stir plate, and make starters that start at 1L, then step to 5L and then 10L over the course of a week - and they ferment out fairly well. My concern is that the 11L yeast I end up with (well, a thick layer of yeast with 10L of spent wort covering it) wont contain anything like enough cells for a lager.
If you look at the yeast growth calculator at http://yeastcalc.com/
and follow the process that I use above for ales, I'm only half way to the correct cell count.
If I change the numbers around in order to end up with the correct pitching amount for the lager, then I have to start with 3L (which sounds too big for 1 vial?), then add 15L followed by another 16L for the final stage.
That's 34L of wort used!!
Am I getting it wrong here? Anyone else make big lagers from vials? Grateful for any advice.

 

[WoodlandBrew]

Because you are using a stir plate you might want to Kai's calculator on Brewers Friend. It was developed using experimental data from actual stir plate starters instead of simply scaling the stationary starter like Mr. Malty does.

However, in my experience, cell counts I have done show a pretty simple relationship between grams of extract and cells produced. The only time pitch rate matters much in a starter seems to be if you don't let the fermentation run to completion or if your cell density approaches 300 billion per liter.

1g of DME -> 1 billion cells.

If it were me, I would brew a batch 1/10 of the volume of the big batch and then use the yeast produced from that beer for then large lager. There are more details on my blog and in my book ( which will be available very soon). It will take about 3 or 4 days to grow the cells, and as a bonus you have more beer instead of wasted wort.

 

[jat147]

Hey thanks for that. The brewers friend calc spits out fairly similar numbers to the yeastcalc one, so I'm sure they're both right.

That's a good idea about a 1/10th brew, I should do more yeast harvesting - I'm just too lazy. Will a 26L brew create enough (viable) biomass to get to the nearly 4000Billion cells needed? It sounds a little small?

 

[WoodlandBrew]

Will a 26L brew create enough (viable) biomass to get to the nearly 4000Billion cells needed? It sounds a little small?

26 liters of a 10°P wort would grow about 2.6 trillion cells. If it was a 20°P wort it would grow 4.2 trillion cells.

 

[jat147]

Thanks again.
20 plato is about 1083 in old money? At 26L thats a heck of a lot of DME!
If my math is right its over 5.5kg - that's gonna cost

 

[WoodlandBrew]

Agreed. Propagating lots of yeast is costly, but still cheaper than buying it all. Instead of doing a starter you can use 1/10th of you beer wort to grow the cell count over a 24 hour period and then add the remaining wort. The only trick is keeping the wort sanitary over that period. You might consider reboiling the wort after 24 hours.

See here for details:
http://woodlandbrew.blogspot.com/2012/12/no-more-wasteful-yeast-starters.html

 

[jat147]

Good article, well done.
Best regards, James

 

[WoodlandBrew]

Thanks! There are some more techniques in my book which will be out soon!