thats great atlatlman, thanks for sharing. I had to have a play, had no polypore at hand so just been and got some from the local woods (plenty of the stuff by me), also having no beef fat I just used lard instead (I know, impatient to have a go), I filled an empty tea-candle holder (completely clean and free of wax) with lard and inserted a 2cmx2cmx1cm piece of polypore in it, it burned very well indeed with a strong 2.5 to 3 flame for 46 minutes (indoors), after which flame died down to a tiny flicker and took another two minutes to completely extinguish, lard was used up but some polypore was still left. I was surprised at how strong the flame was. I did wonder if you had used dried polypore and thought it might not work with freshly picked, however my polypore was about 90 minutes old from picking and it worked fine. Thanks for the good post resulting in my afternoon entertainment.
This is my effort