Want to double my yeast vial to make 2 batches

[mthhurley]

I have a single vial of WLP001 and I'm going to brew two different batches.
I'm in no hurry here, so is it possible to continue to step this up to get me to 500 billion cells and just split it in half?

I've already pitched this vial and done my first 2L start, so I'm around 200-250 billion cells. I decanted it down to just the yeast and looking to pitch it into another 2L starter. Will that get me to 500 billion or some smaller number? I do not have bigger flask than this 2L in case someone suggests making a 4L

Thanks!

[robert4136]

that sounds good to me, I don't think you'll get the same rate of growth because the second starter will be staring with more yeast while the volume and gravity of the starter will be the same. I believe that the more yeast you initially pitch, the less growth you will have.

[Oktober]

Use Jamil's Yeast Pitching Calculator, which will give you a good idea how much yeast you will have after any given starter. If you have your starter on a stir plate, you'll see the yeast growth accellerate too.

And yes, if you have 500 billion cells, you can easily just split it between two seperate batchs - its a great way to stretch a single vial of yeast.

[mthhurley]

Use Jamil's Yeast Pitching Calculator, which will give you a good idea how much yeast you will have after any given starter. If you have your starter on a stir plate, you'll see the yeast growth accellerate too.

And yes, if you have 500 billion cells, you can easily just split it between two seperate batchs - its a great way to stretch a single vial of yeast.

Maybe I'm missing how to use Mr Malty for this, but I don't get how to use that calc to back into this. I know it can tell me how many cells I need and how many liters I need based on OG...but how do I say "I want 500 billion cells and am starting with 100 billion"?

[a10t2]

You just have to trick it a little: Two-Stage Starter Calculations