Yeast calc with slurry in starter

[hawktrio]

I'm wondering how to roughly calculate yeast cell counts in prep for my next brews given my process as follows:

12/7/14 - Pitched rehydrated new single packet S05 into 1.048 blonde ale.
12/19/14 - FG reached of 1.012 cold crashed in primary at 0℃.
12/22/14 - Racked to keg and placed yeast cake into 1 litre mason jar at 4℃.
1/29/15 - Decanted beer from mason jar leaving 400ml slurry which was then pitched into 2 litre yeast starter and placed onto stir plate at room temp.

I'm wondering if I can now let this go for a day or two then cold crash then decant and pitch onto 1 or 2 brews both around 5-6% abv?

 

[WoodlandBrew]

You're probably looking at about 800 billion cells. Viability of the slurry should be very good. The cell density will depend on how much protein was transferred from the kettle to the fermenter.

 

[Sippin37]

Google MrMalty yeast calculator and you can find out the number of cells after adding a few numbers.

 

[hawktrio]

Thanks WoodlandBrew! I ended up pitching 1/3 into a 1.066 American Amber and the other 2/3 in a 1.098 RIS. Sippin37 I'll have a play with that calculator and see if I can work out how WoodlandBrew got his estimation. Probably should've done this before pitching but never mind.

 

[WoodlandBrew]

There's not a whole lot to my calculations. For cell density without using a hemocytometer or cell density meter it's really just a rough estimate. ABV of the beer was low and the yeast was refrigerated for a short period of time so viability should be good. 400ml at 1.5 billion per ml is 600 billion cells. A two liter starter will grow about 200 billion cells.