I was perusing a catalogue in my local home brew shop recently and came across an immersion heater that you basically plug in and drop in a bucket. It was designed for beer use, but I was thinking of the possibilities of using it for wine and mead. I usually only use enough hot water to dissolve the sugar and, depending on the wine, cover the fruit/vegetable matter for extraction. I would advise removing the heater before adding sugar. My next batch of mead will probably use a raw local honey so I could use it to heat water up enough to pasteurise it, should I wish to do so.
Has anyone got any experience with these? Any other thoughts? It would be a lot easier than filling up a few large pans for hot water, and it was less than half the price of a 2 gallon kettle I was looking at recently.