I’m brewing 2 different high gravity beers that use the same yeast. I want to just buy one vial of yeast and step it up to the proper amount. I don’t know if 1 2L flask will be enough for essentially quadrupling the vials cell count. What would be the best way to make a yeast starter that I could pitch into both of them and ensure I have the correct amount of yeast going into each carboy.
its a bit of a crapshoot, but very do-able. The problem ultimately becomes, how do you split up the slurry and how much is in each, but if you overshoot the calculated needed yeast by a bit, you can just do it by volume.
Now comes the problem of your flask…its pretty small for that much yeast.
Have you considered making a 5 gallon batch of a small (1.040 max), not-very-hoppy beer like an ordinary bitter from one vial, then you will have more than enough for your boozebombs? I do this a lot when we are brewing a higher gravity beer or lager on our 1/2 bbl system (and I often like the session beer better!)
+1 I was thinking the same thing. 2 batches may be hard, but 3 is a no brainer. The starter batch could even be a 3-gallon BIAB Kit.