BeerSmith™ Home Brewing Forum

BeerSmith Software => BeerSmith 2 Questions => Topic started by: Grumpyowl on June 10, 2011, 07:52:08 PM

Title: Yeast Starter Formula with Stir Plate
Post by: Grumpyowl on June 10, 2011, 07:52:08 PM
Hello there,
Great software!  Learning the new features.
Just curious if anyone played with the yeast starter yet.
It seems that selecting "stir plate" for liquid yeast results in fairly low starter size needed.
I get less than 1 qt using OG of 1.083 and 5 gallons batch.
Other pitching calculators i have used before give rather higher (1.7 qt) results.
Comments? Insights?
Thanks!
Olivier
Title: Re: Yeast Starter Formula with Stir Plate
Post by: MaltLicker on June 10, 2011, 08:06:23 PM
Verify the date of production is the same, but yea it is different from Mr Malty.

Of the numbers I can see in both, the numbers are very close.  

BSmith has a separate stir plate factor that I don't see in Mr. Malty.  
Title: Re: Yeast Starter Formula with Stir Plate
Post by: maddspoiler on June 10, 2011, 09:51:30 PM
Could it be that stir plates work that well?
Title: Re: Yeast Starter Formula with Stir Plate
Post by: BeerSmith on June 10, 2011, 10:24:05 PM
Hi,
  You can adjust the stir plate factor and also the growth limit from the Options dialog->Yeast starter if you think the defaults are too high.

  In general stir plates are pretty effective.

Brad
Title: Re: Yeast Starter Formula with Stir Plate
Post by: Waldner on June 21, 2011, 01:55:58 PM
I am also enjoying the new software but have also noticed that BeerSmith calculates a smaller starter size than Mr. Malty.  However, when playing with the numbers on Mr. Malty I've noticed that I cannot get the starter size to drop below 1 liter when adjusting either the OG or volume.

Perhaps this is a limitation of the Mr. Malty application and BeerSmith is calculating a little more accurately. Just guessing here, maybe someone else knows for sure.
Title: Re: Yeast Starter Formula with Stir Plate
Post by: merfizle on June 21, 2011, 03:29:18 PM
I don't make a starter any smaller than a liter.  It's good to have plenty of viable yeast!  I did a 1 liter starte for a 1.030 Cali Common and it turned out great.

Mark
Title: Re: Yeast Starter Formula with Stir Plate
Post by: BeerSmith on June 21, 2011, 09:00:47 PM
Hi,
  I did not include starters less than a liter either (in the recommended column) as they don't accomplish much when you are pitching a typical 100 billion cell pack.  However some people working with slants want the ability to work with small quantities, which I'm going to look at in the future.

  I have not done a direct comparison with Mr Malty - most of the equations I derived from the new Yeast book that Chris White and Jamil did.  However, one obvious difference might be where you set the cutoff for starter growth limit (mine is 3.0).  This basically determines how large a starter can get before you give up and toss another packet of yeast in.  If this is too large you end up with the starter being almost as big as your beer.

Brad
Title: Re: Yeast Starter Formula with Stir Plate
Post by: Waldner on June 21, 2011, 09:37:08 PM
Thanks for the explantion Brad but I have a follow-on question.

You said you did not include the ability to calculate starters less than 1L. However, when I input a ale with with 1.047 OG, 2.75 gallons and a viability date of 5/18/2011, using a stir plate in the box titled "starter size needed" I get .39qts or .37L. 

Is this being calculated correctly then or am I misreading the information?

Thanks again