I have washed 3 and reused 2 yeasts ... one being the WPL005 mentioned above, and the other was some "Funktown" ...
I am pretty sure I washed, sanitised, everything correctly, and don't feel that there is anything wrong (colour or smell) ... both of these yeasts have gone off like a fire cracker compared, to the first time I used them. The Funktown was bubbling away as I poured it into the wort, and the wort seemed to start fermenting within an hour ... this morning it had blown a heap of junk out the blow off, and has pounded away all day, and filled a second/replacement blow off tube with junk too ... the wort is swirling away like crazy all day.... not that I have not seen any of this before, but nay sir, never this volatile.
So my question is, is that all fine ... maybe an over pitch? ... I pitched half of what I washed (one of 2 jars) which was 180 - 200ml into a 5L wort (at 20C)
cheers