Thanks for the quick replies, guys. I think there
is too much water in it. I've already add another package with a smaller ratio of water, but I may prepare an even thicker mixture with cool water and add it to the rest to thicken it out, ala Osage's advice. For the moment I'm letting it heat to see what happens.
I'm also curious about saving the leftover, Osage. What I had read was that you could stick it in the fridge to cool it, and then pour it out over wax paper to let it dry into flakes, which can then be stored in an airtight jar. Does that jive with what you know?
Most of what I know comes from TBB1&2, and a bit more from here, but I haven't actually put any of that 'book knowledge' into practice yet, sooooo.......