Oh well, I've tried three separate times now and every time I've got brown sludge. It looks brown before I reduce it, doesn't change when I reduce it and doesn't change when I attempt to burn it off. It just sits there and looks brownly at me.
I've also tried not reducing it as I thought the hot head might be doing that naturally but it made no difference.
Only thing I can think of it that I'm using doubled up leaf (have even tried quadrupled leaf with no success) as I have no foil and if that's the problem I'll just have to wait until I'm rich enough to buy some foil. Grumble mumble humph.