I’ve read in Mosher’s Mastering Homebrew that a direct fire set-up, wherein the flame actually touches the kettle (I use stainless steel) will effect the flavor of the beer. He doesn’t go too deeply into the subject, but I’m concerned that this might have an effect on the beers I produce.
I’ve used aluminum in the past and the brews have not had any overly metallic or scorched flavors. Is this something to take seriously? In what conditions?
And to add to the metallurgy concerns, I also drop my copper wort chiller in the boil about 15 minutes before flame out. Anyone see a concern here?