Where do melanoidins come from in beer? What characteristics do they bring to beer?
Melanoidins are created by Maillard reactions, but melanoidins themsleves add only color, not flavor to beer. The Maillard reactions that create melaniodins are what cause the flavors. Wort does not caramelize in the kettle. Caramelization requires temps in excess of 360F and exposure to O2, neither of which happens in the kettle.
The very first BrewStrong episode was all about melanoidins. Very useful.
They are also created during malting, so you can carry them through from the malt into the beer.