Yeast starter question about what to pitch...

I am brewing up a fairly big IPA tomorrow OG should be around 1.070ish... I am currently making a 1600ml starter of Wyeast 1056 with 160grams of LME... my question and forgive me if its a total noob question is after the fermentation gets going in my starter, do I pitch the entire contents of the 1600ml flask into my primary or do I pour off the top lets say 1400ml and only pitch the little yeast cake at the bottom??? Thanks for your help!

In a perfect world you will keep the starter going for 2 - 3 days ( with a stirplate or the shake it every time you see it method). Then refrigerate for 24 hrs, decant liquid, swirl yeast into suspension and pitch. I just did a 1L starter and pitched entire thing into 1.068 wort after only 24 hrs and batch is happily fermenting away.

so you think pitching the whole slurry of 1.6L should be okay? For a heady IPA I don't think it should matter that much as if it was a very light beer... I have just been getting some sweetish beers that have had higher OG's and i think it was due to just pitching one Wyeast pack straight into the wort...

if you pitch the starter WHILE it is fermenting (krausen, etc) then you need to pitch the whole thing. If you wait until AFTER it has fermented, you can decant the top and pitch the bottom