First yeast starter help

I'm going to make my first yeast starter. I plan on brewing on Friday or Saturday. Just want to make sure Ive got everything figured out.


Making a 1.055 beer, 5 gallons

I will make the starter 24 hours in advance....so on Thursday. Plan on brewing friday...or saturday.

1 liter starter: 4 cups of water and 1 cup of DME to hopefully come out around 1.040. Is it worth the trouble to measure the SG, I figure it should be close within reason. Would a 1.5 liter wine bottle be large enough, if not I can use a 1 gallon wine jug.

My unknown and real question:
I am using old slurry of US-05 that I bottled in a 12 oz beer bottle from December. It was not washed but had minimal hops. I used a hop sack and it was from a centenial blonde batch. In the 12 oz bottle the liquid separated and I would say I have 8 oz of slurry. If it was only a week or two old I would just use it, but I figure being 2 months old I will make a starter to verify its viability.

I looked at Mr malty and I need about 200 billion cells?

I'm estimating 50% viability for being 2 months old
20% non yeast material
average yeast thickness

That tells me I need 175 ml of slurry
1 oz = about 30 ml so I only need about 6 oz of slurry.

But I want to wake it up and make it healthy with a starter. So I was thinking of taking 6 oz of slurry and making a 1 liter starter. But will i overpitch if I do this?? Will a 1 liter Starter vary significantly with the amount of initial yeast introduced?

My other thought is to make a one liter starter and then only use 6oz of the slurry and save the rest if there is enough?

Also does 24 hours sound long enough to do this?
Should I take my stored yeast slurry out of the fridge now to get it acclimated to ambient temps.

thanks in advanced.
I'm probably making this too hard. I'll also have a pack of dry us 05 ready in case I mess up the starter.

 

check out MrMalty to figure out how big of a starter to make. check out this thread to see how to put together that starter.

 

Gotcha!

My plan now:

I need about 200 billion cells

according to Mr Malty a 1.72 liter starter will double 100 billion cells to about 200 billion cells.

So I need 100 billion cells from my 2 and 1/2 month old slurry.
Mr Malty assumes 10 percent viability past 2 months old which I am refusing to believe. My assumptions in Mr malty calc are 50 percent viability, 200 billion cells per ml (thin), and 25 percent non yeast material (not washed). This tells me I need 235 milleters of slurry for a direct pitch. But I only want half of that to propagate more with the starter. so I need about 115 ml of slurry in the starter which comes to about 4 oz of slurry.

so I will be pitching 4 oz of slurry into a 1.7lt starter.

Does that sound reasonable to you folks that make starters from slurries?

 

yeah, i rarely pay attention to the viability when making a starter from slurry, i pitch around 100 ml of solids into the starter. if it's a big starter or older yeast, i do it in two steps, half size fermented fully, decanted and i pitch that slurry into the brewing size starter.