Harvesting yeast at high krausen?

I have a few unopened bottles with a thick dense cake of Wyeast 1272 American Ale II in the bottom of them. I plan on pitching the yeast from two of the bottles into a 3 gallon cream ale. I was thinking of taking a quart with a wine thief at high krausen and saving it as a starter in a sanitized mason jar. Can I put it in the fridge, then take it out and let it warm up to reactivate the yeast or should I let it ferment out then pour off the beer and top off with sterile water?

I have done yeast washing from primary and secondary after fermentation was complete with good success. Any insight?

Nate

Typically, you want to make a starter when trying to harvest dregs.

The action you are describing with the wine thief is top cropping. I don't think you would need to add sterile water for any particular reason, though I might be misunderstanding your question. With top or bottom cropped yeast, you have a limited window of repitches (i.e., a couple generations) before genetic drift can get to be a problem, but what you are describing here should be fine.