Homebrewers Association | AHA Forum

General Category => Yeast and Fermentation => Topic started by: micsager on April 02, 2010, 02:20:00 PM

Title: Starter/stir plate 10 gallon batches
Post by: micsager on April 02, 2010, 02:20:00 PM
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?
Title: Re: Starter/stir plate 10 gallon batches
Post by: Hokerer on April 02, 2010, 03:03:44 PM
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.
Title: Re: Starter/stir plate 10 gallon batches
Post by: a10t2 on April 02, 2010, 03:04:58 PM
Are you familiar with the MrMalty calculator (http://www.mrmalty.com/calc/calc.html)?

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.
Title: Re: Starter/stir plate 10 gallon batches
Post by: micsager on April 05, 2010, 02:38:41 AM
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.

Can descibe "step up" for me.  I get the basics, but do you have specific instructions?
Title: Re: Starter/stir plate 10 gallon batches
Post by: a10t2 on April 05, 2010, 03:26:49 AM
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: http://seanterrill.com/2010/03/23/yeast-ranching-and-you/
Title: Re: Starter/stir plate 10 gallon batches
Post by: micsager on April 05, 2010, 03:30:32 PM
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: http://seanterrill.com/2010/03/23/yeast-ranching-and-you/

Thanks Dude, happy brewing.