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**alfista** · 07-19-2012, 06:38 PM

Hi all,

I'm trying to use yeastcalc or mrmalty to figure out how to scale a fresh vial of yeast from 100bn cells to 800bn using a 1.8L flask and a stir plate. I can't seem to find a good guide on how to do this. Any thoughts, tips?

Cheers,

Jason

**tally350z** · 07-19-2012, 06:47 PM

You would have to do a multiple step starter. Maybe even like 5 or more, 1-1.5 liter starters. Might be best to use more than 1 vial if you have access to more..

pabloj13 · 07-19-2012, 06:54 PM

3 1.8L starters would get you to ~750 billion cells. Of course, you won't be able to fit that much in your flask. Probably 4 steps as much as you can fit in the flask will get you close. I would get a larger flask, personally. 2 3L starters would get you there.

**tally350z** · 07-19-2012, 07:00 PM

Just out of curiosity what are you going to make that requires 800B cells?

**osagedr** · 07-19-2012, 07:04 PM

Well there might not be any tips outside what you already know given your equipment.

A couple of other thoughts: (1) make a smaller beer, then use slurry in your big beer. (2) use dry yeast. Neither of those might be optimal, but either of them will work to get you to 800 billion+ cells if you don't want to take the time to make multi-step starters.

**alfista** · 07-19-2012, 07:51 PM

Thanks all for the tips.

The thought was to replicate some yeast without going through the yeast washing process, for a few upcoming batches of beer. I don't mind the time and effort as my stir plate and flasks have more downtime than the carboys, and I thought it would be a fun thing to do from an educational perspective. From a process perspective, I was interested in the math of the stepping process to not over-stress the yeast.

pabloj13 · 07-19-2012, 09:01 PM

Quote:

Originally Posted by alfista

Thanks all for the tips.

The thought was to replicate some yeast without going through the yeast washing process, for a few upcoming batches of beer. I don't mind the time and effort as my stir plate and flasks have more downtime than the carboys, and I thought it would be a fun thing to do from an educational perspective. From a process perspective, I was interested in the math of the stepping process to not over-stress the yeast.

Honestly I would do it a different way. Rather than step up to such a huge amount of yeast. I would just get up to 20-30 billion yeast in a jar per batch. Then you can just do a quick two-step starter when you are ready to roll. 500mL > 1.5L and you are up over 200 billion cells. A lot easier, IMO.

duboman · 07-19-2012, 10:48 PM

Keep in mind that the idea of a starter is not just to grow yeast but to grow HEALTHY yeast that performs optimally. By trying to just grow a huge amount of yeast to have on hand over time you are actually being counterproductive(IMVHO)

**msa8967** · 07-20-2012, 02:54 AM

Quote:

Originally Posted by duboman

Keep in mind that the idea of a starter is not just to grow yeast but to grow HEALTHY yeast that performs optimally. By trying to just grow a huge amount of yeast to have on hand over time you are actually being counterproductive(IMVHO)

Could you expand more on explaining the difference between increasing the yeast cell count and increasing the amount of healthy yeast cells? I would like to know about the proper way to raise more healthy yeast cells or at least things one should avoid in building up a starter.

pabloj13 · 07-20-2012, 10:40 AM

Quote:

Originally Posted by msa8967

Could you expand more on explaining the difference between increasing the yeast cell count and increasing the amount of healthy yeast cells? I would like to know about the proper way to raise more healthy yeast cells or at least things one should avoid in building up a starter.

It's all about inoculation rate or the number of cells per mL of wort. The OP can step up starters over time to achieve 800B cells in that small flask, but those cells will be competing for a limited amount of nutrients, oxygen, etc. This will stress them out and weaken them. Ideally you would just keep a smaller amount of yeast stored in the fridge and do a quick step up before brew day.