Author Topic: yeast starter tool is off ?  (Read 6796 times)

Offline aschecte

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yeast starter tool is off ?
« on: January 28, 2012, 08:06:24 AM »
This may have been posted before but I'm not finding it. I have punched in all my numbers batch size, OG , ale, etc and double checked all yeast starter settings which show the accepted "rule of thumb" numbers ie. .75mil/mil plato for ales 1.5 for lagers etc. now for my question beersmith 2 says I need to make a 1.14 liter starter with 1 smack pack or vial on a stir plate. Now for comparison on mr .malty or ANY other starter program for the same exact settings with the same batch size and the same OG (1.069 ) all programs say I need 261 billion cells but allt eh other programs require a 2.64 liter starter for 1 pack on a stir plate. This is more than double the size that beersmith says I need. why ? either beersmith is correct and everyone else is wrong or I'm doing something wrong or beersmith is off in its calcs. Please anyone that knows about this please help. Thanks.
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Offline jomebrew

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Re: yeast starter tool is off ?
« Reply #1 on: January 28, 2012, 11:05:50 AM »
Actually, there is something wrong with the calculator

in the starter pack cell count box, increment through the numbers starting at 1 billion and watch the starter size needed change going up and down.  e.g.

Vol 5.5, gravity 1.069, liquid yeast, harvest 1/23/2012 (92.30 viability), use stir plate.
Starter Pack cell count 6 billion, starter size 1.44L
Starter Pack cell count 7 billion, starter size 1.17L
Starter Pack cell count 8 billion, starter size 1.29L
Starter Pack cell count 9 billion, starter size 1.44L
Starter Pack cell count 50 billion, starter size .98L
Starter Pack cell count 100 billion, starter size .46L
Starter Pack cell count 200 billion, starter size .98L



Offline aschecte

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Re: yeast starter tool is off ?
« Reply #2 on: January 28, 2012, 09:00:07 PM »
Well I kinda fel better. I comprimised as I didn't know which program to trust and  as I'm brewing tomorrow ..... I made a 2L starter. I'm underpitching but I'll be better off than if I didn't make one at all. Do you or anyone else know if there will be an update with a fix for this ? I love and live by this program and I would hate for this portion of the tools not to be trusted or to function properly.
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Offline jomebrew

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Re: yeast starter tool is off ?
« Reply #3 on: January 29, 2012, 10:46:49 AM »
The BS2 tool is very thorough and complex.  I prefer to use the simpler tools like the one on my web page.  I am not plating cells and counting them under a microscope. 

I know I need a lot of healthy yeast cells and they healthier they are the better they will perform their alchemy on my wort.

I know a 2L yeast starter will yield about 250 billion cells in 2 days from one vial.     For a 1.070 beer and under, this will be fine.  Over 1.070 is risky but that does not mean it will not work.

I just brewed a 1.108 Imperial Oatmeal Stout and poured in 1.6 liters of a 2 liter starter that was 48 hours on a stir plate.  The yeast attenuated 80% of the fermentable sugars with WPL001.  The Vial was 30 days old.  I Used O2 on the work for 90 seconds.  chilled the wort to 58F and pitched the active 001.  I added a heating pad after 24 hours to start warming.  After 24 more hours, it was in the mid 60's and fermenting nicely.  I checked the gravity after 6 days and it was at 1.020.

  • Mr Malyty tells me I need 2 vials and a 2 liter starter. 
  • Beersmith 2 says 1.3L and 1 vial.
  • My simple calculator says I will need a big starter and 2-3 packs.
  • The math tells me I should start with 400 billion cells.  1 vial in 2L starter should produce up to 250 billion .  I need 400 billion so I need 2 vials in a 2 to 4L starter (which is how general I wanted my tool to be).

Reality is that a very active, healthy starter in a well controlled fermentation environment produced a very good beer and I got lucky.


Offline Kevcor

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Re: yeast starter tool is off ?
« Reply #4 on: March 31, 2012, 07:47:23 PM »
Interesting stuff on yeast starter. I am fairly new to the SW I just added a recipe for an 10 gallon IPA. I was told by the local brew store that on pack of wyeast 1056 using a 2L starter/stir plate would produce enough yeast cells. On the Yeast Starter tab in my recipe it says I need 12 packs with starter??? There must be some settings I need to change. Any thoughts. I have used the 2L one pack for sometime and seem to have good success, but if I should be adding more then one package it would be good to know.

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Offline kgs

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Re: yeast starter tool is off ?
« Reply #5 on: April 15, 2012, 08:18:51 AM »
I too was puzzled by the starter calculations... 19 vials if I don't make a starter? I always make a starter if I use liquid yeast, but... seriously?

I think I know where the problem lies (maybe...). In calculating the starter for a 6-gallon batch of 1.068 OG (a foreign extra stout), using WLP002, I noticed that within the yeast description for WLP002 it said that it had 100 billion cells BUT that the viability for these cells was 5%.

I am no scientist, but I think I would have to buy yeast past its pull date and walk around with it in my purse for a couple of days to hit 5% viability. Just a hunch that this is driving some of the results seen from the yeast starter calculator.

Edit: I realized the date of the vial in the calculator was set to 3/1/2011... so it was past its pull date! I set it to 3/1/2012 (deleted and re-added yeast to my recipe) and viability jumped to 67%; I set the yeast package date to today (I know, not realistic, just testing), and viability jumped to 96%.  At 67% viability, the calculator claims I would need 5 vials without a starter and 2 with; at 96% viability, it's 2 vials/1 vial.

The viability rates accord with what I see in Mr. Malty, and the recommended starter amounts correspond as well.  So in this case it was the user who was broken.
« Last Edit: April 15, 2012, 09:04:14 AM by kgs »

Offline makenzi

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Re: yeast starter tool is off ?
« Reply #6 on: April 16, 2012, 06:50:09 AM »
try this...
http://www.yeastcalc.com/index.html
I'm pretty satisfied with it.