Several questions here...
First time I've harvested yeast to use at a later date. I usually just pitch right on the cake. I have a 800ml (24oz) jar that has settled into 300ml of thick yeast with about 300ml beer that was left on the slurry on top. The yeast was harvested 12/28. It's 3rd gen 1056. I plan to use it in a cream ale OG 1054.
Mr.Malty calculator says I need 600ml slurry based on the date. He says it's only 10% viable. That amount is just slurry- not slurry in a starter, correct? So if I put the slurry I have in an SG 1035 1.5L starter on a stir plate I should be pretty close, yes? I probably won't double the volume so it may be an underpitch, but it should still be enough, yes?
I'm also making a second batch of the same cream ale and using WLP001. That is the exactly the same as 1056, yes? The only reason I'm buying WL is because I got a coupon. Not that there is anything wrong with WL. I have just always been a Wyeast guy. I will make a starter with that tube.
I'm looking at this as a yeast experiment. Theoretically the beers come out exactly the same. We shall see. And it is also kind of an experiment with the stir plate. First time using it. And it's homemade. I figure I'm really putting it to the test throwing 300ml thick slurry in 1.5L starter.