The usual rhythm of the brewing process has been disturbed by leaking mash tun plates passing grain, as you'll clearly appreciate from this photo of the wort collection sight glass.
It's a minor annoyance in the grander scheme but things run best when they run smooth and that applies to this little beer making contraption that I call a brewery, more than most. I don't know the precise cause yet but I suspect I'll find a small plastic riser (er, a raw plug pressed into action the last time this happened, about 3 years ago) slightly out of place when I clean the tun. Grrrr.
We don't want grain in brew; the husks contain polyphenol material that will cause haze problems and possibly a slightly harsh flavour. I'll finish collecting the wort in 9 minutes time, leave the copper to stand for a further 9 and then tap off a gallon from the base of the vessel. This ought to remove much, if not all, of the errant cereal, rendering this batch serviceable.