I don't use anything to thicken. I cook it to the thickness I am comfortable with. Usually, when I lift my wooden spoon out a "string" of gel drops and hangs just a bit.

Hard to describe.
I haven't been using any other gel lately. Dewpoints are in the low to mid-60's here right now. All bets might be off though once the summer heat gets here. I'm just enjoying it for now...