Small Yeast starter

[callback79]

Hi,

I'd like some opinions on this one. Sorry for all the maths.

I have a Wyeast smackpack dated 2012-10-23. I would like to make a starter bigger than what I need for my next batch to keep some fresh yeast for next time (Inspired by THIS). I only need to pitch 107B cells.

I only have a 1.5L jar to make the starter. From YeastCalc calculations, my smackpack contains around 56B viable cells.

My plan is to make a 1L starter, that will give around 167B cells, storing 750ml for future batch (around 112B cells) and keep the remaing (55B cells) to make another starter. A 0,5L starter should give me around 120B of viable cells, a little higher than the 107B I need.

Is the second starter (0,5L) too small ? I read many threads where the smallest starter should be at least 1L, but this is for an entire smackpack. My mind is it can be OK since I only use a portion of the initial pack.

A 1.6L starter will be perfect (Will give 208B cells) but my jar is not big enough.

Any thoughts or recommendations ?

Thanks.

 

[duboman]

Check this out!
https://www.homebrewtalk.com/entries/yeast-harvesting-novel-approach.html

 

[keyman]

Check this out!
https://www.homebrewtalk.com/entries/yeast-harvesting-novel-approach.html

Is there a rule of thumb of knowing how much yeast cake at the bottom is enough? I have about 1/8" of yeast cake at the bottom of a pint jar. Is this enough to make a batch of beer?

 

[duboman]

A general rule of thumb is 1-2 million cells per milliliter.

If you harvest yeast from the starter as the article I provided suggests you will not have enough to direct pitch a batch but will have enough to create a starter like if you were to buy a new vial or smack pack give or take a few million cells

A new vial or smack pack contains 100B cells when new and fresh and a full 5 gallon batch of 1.060 beer could take 250-350B cells for proper pitching rate, hence the need for a starter.

If you are not familiar with these sites you should visit: http://www.mrmalty.com
http://www.yeastcalc.com

 

[keyman]

I am sorry here but maybe I have some sort of brain fart. My question is,,,since I washed the yeast and put it in a one pint mason jar how do I know how many yeast cells I have? Is there a way of measuring to see how many yeast cells I have. The cake is only 1/8" thick, is that enough? will the starter provide enough?

 

[duboman]

I am sorry here but maybe I have some sort of brain fart. My question is,,,since I washed the yeast and put it in a one pint mason jar how do I know how many yeast cells I have? Is there a way of measuring to see how many yeast cells I have. The cake is only 1/8" thick, is that enough? will the starter provide enough?

Did you not read any of the previous posts??

Go to: http://www.mrmalty.com/calc/calc.html, plug in the numbers for your yeast and select "repitch from slurry" to calculate the size of starter and pitch rate you require.

 

[Transamguy77]

Did you not read any of the previous posts??

Go to: http://www.mrmalty.com/calc/calc.html, plug in the numbers for your yeast and select "repitch from slurry" to calculate the size of starter and pitch rate you require.

I understand what the OP is trying to say, I had the same problem when I started making starters.

When you use a yeast calc how it works is it uses the size of the starter at 1.040 to determine the yeast count, it doesn't use how thick your slurry is at the bottom of the jar cause not everyone uses the same jar/flask.

You can just pitch what you have and hope it's enough or make a starter and know its enough.

 

[WoodlandBrew]

Im my experience the viability estimate is lower than what it really is. You probably have more like 75 billion. 1 billion cells per ml is reasonable for a slurry.

The only way to really know how many cells you have is with a cell count.
like this:
http://woodlandbrew.blogspot.com/2012/11/counting-cells.html


Ok I'll do it for you
http://woodlandbrew.blogspot.com/p/normal-0-false-false-false-en-us-x-none.html?m=0