Large yeast starter - too many steps?

I made my first yeast starter over two weeks ago and I wasn't able to use it at the time, and sine then I have just kept stepping up every few days and then chilling/decanting just to keep it going. It is Wyeast 1056. I have gone from a pint , to a liter, then another liter, and am currently up to two liters.

My question is, I have a high gravity beer I want to make this weekend (1.080) that yeastcalc says needs a 3.6 liter starter, so should I just make the next one at that size and call it good using what I have grown so far, or have I been doing this long enough that there are too many hanging out in there? I don't know how to measure them and I don't want to pitch 600 billion instead of 287-300 billion and have possible off flavors.

Does anyone know the approximate amount of slurry to pitch from a 4 liter starter? I figured that would be the easiest method if I could just portion the slurry and save the rest.

If all else fails I will probably just split this batch and use half to make the 3.6 liter starter.

 

Did you start with a smack pack tossed into a 1-pint starter? You should have either done a 1L and then up to 3.6L or 4L, or just gone directly into a 3.6L starter.

Are you decanting the liter of spent wort and then adding another liter of wort on top of the slurry? If so, you aren't getting any growth. The yeast has already produced a large enough colony for 1L, so it is just eating the new sugar with little to no cell divisions before going dormant again.

Take a look at this thread for some guidance on making starters: http://www.homebrewtalk.com/f39/how-make-yeast-starter-pictorial-76101/

For a 3.6L starter, you need to inoculate 3.6L of starter wort and that will yield the correct number of cells. If it is more practical with your equipment, you could also do 2 separate 2L starters. When you pitch, add the entire slurry from one of the starters and 3/4 of the slurry from the other.

 

That's exactly what I was looking for, thanks!