A week ago, I was trying to harvest the WLP005 I had used to brew an english bitter. I had a really hard time separating the yeast from the trub.
This was one of our first all-grain beers and for whatever reason, there was a lot of trub in this beer. The WLP005 is highly flocculation, so I think it was sticking to the trub quite a bit and being difficult to wash out. It took a couple tries, but I eventually got a couple of thin yeast layers that got pitched into a starter a couple days later. (1 qt @ ~1.041) It was a little slow to start, but in retrospect the growth cycle was about the same as the original generation out of the tube.
Now the starter is in the fridge, and there is maybe a half-centimeter or quarter inch of yeast on the bottom. I'm guessing the "thick slurry" is 1.5+ oz 50 ml or so. That would put me too low for repitching according to the Mr Malty calculator. (1.060 for the next beer)
Then again, it doesn't account for the fact these yeasties are not just harvested, but regrown in a starter... If I assume I could bump the harvest date up to the day I stuck it in the fridge, I could just barely be in the ballpark.
BTW, we checked out the starter wort this morning, and it seems fully fermented and the flavors left behind seem normal.
So I'm brewing Fri. or Sat. and I'm thinking I either pitch as-is with my finger crossed, step it up with a 1.5 qt @1.060 starter, or beg you-know-who to swing by the homebrew store since they all close before I can get home.