As for percolators, yuck! I've never had a cup of percolator coffee that didn't suck. Always tastes burned.
Have only seen this with dirty percolators or stovetop versions that are left one too long.
Just cleaned mine last night by running 1/2 vinegar and 1/2 water and it tastes great.
I go by the Hazel Burke rules - a clean pot makes good coffee, and 1 spoon per cup plus 1 for the pot. Darn tootin' !
It's true that "gourmets" will never get the water too hot for their coffee.
Then again I'm not willing to spend $10 on anything less than 3 pound of coffee

Like beer, I don't drink it for the fine nuance in taste LOL.
That's what fine whiskey, Bordeaux, and espresso are for on special occasions.
Good read on the cold coffee.
How long can you store the concentrate, say if you froze it ?
Going to have to make some to try it heated up by adding hot water instead of milk.