I'd like to mix my D-76 with with distilled water but am wondering what is the best way to raise it to the recommended 125F for mixing.

I am considering using the microwave but I remember that years ago when I tried to heat water for instant coffee in it, it was awful. It seemed to introduce a sort of weird micro-carbonation into the water. I'm afraid that this would have a bad effect on the solution.

Does anyone have any thoughts on this?