Has anyone used black food grade coloring, in place of cocoa or coffee, to get the black color? Would the food dye kill the SD beasties?
Don't know what I would do with that dark matter. I try to stick to natural ingredients and natural ways of getting the dark color in my food. I don't even like the idea of putting dyes in bread or food. It's artificial.
Serve your rye on a white plate, then it will look darker!
darkness comes with a long cooking at low temperatures (max 150C)
I've used caramel coloring. Bought a small bottle in an asian food store. You can also melt/cook/burn sugar in a pan on the stove and use that to darken your rye. I've also done that. I don't remember specifics re: high heat vs.low heat, etc. but you could probably google it.
... use whole grain dark rye flour. you won't need artificial coloring of any kind.