Chief perpetrator Steve August on the shores of Pigeon Island in Lake Wakatipu with an earlier prototype tub and burner.

Over five years of development, we’ve evolved through seven models of burner and various modifications to the tub. We’ve done over 100 recorded time trials: every time you change a variable it needs another time trial to see the effect of that change. As a spinoff, this does mean a lot of tub parties.

We reckon we’ve got it right.