Hi, Dame Hilda Bracket here!
This will sound a little strange (well, perhaps not coming from me), but how do you test for biodiesel besides doing a 3/27 or running it in an engine?
I've been playing with my soap (don't bother with the bath-time jokes) and I think I may have produced biodiesel. It gives a respectable 3/27 result, but as I only have about 50ml running it in a car isn't piratical.
Anyone any ideas?