I’ve decided to try and “dial in” an american amber ale from JZ and Palmer’s book “brewing classic styles” I have a ten gallon system.
I have a stir plate, with a 2000ml flask.
Should I start with two vials or smack packs, or can I grow enough yeast for a 10 gallon batch with only one?
You can grow enough yeast from just a single cell if you want so you certainly don’t need two smack packs. It’s all about how many times you step up your starter.
Are you familiar with the MrMalty calculator?
According to that, 1.8 L on a stirplate will get you up to about 1.040, and with two packs up to about 1.060.
Can descibe “step up” for me. I get the basics, but do you have specific instructions?
Essentially, you do everything the same, but you repeat the steps, increasing the size each time.
Generally you want to pitch a starter around 10-100 million cells/L. So even if you’re starting from a very low cell count, say a billion, you could pitch that into about 25 mL of starter wort, let it ferment, then go to 100 mL, then 500 mL, then 2 L, and be back up to what you’d need for full five gallon batch. (Roughly, I didn’t bother to do the math.) Which is handy when you need to build back up from an old and/or small slurry, like what would be at the bottom of a bottle. I actually do propagations like that pretty frequently: Yeast Ranching and You « SeanTerrill.com
Thanks Dude, happy brewing.