"Black Rye Flour," DE T2500?
I have been enjoying baking from Lutz Geißler's blog quite a bit. I'd like to make his 100% "Malzkruste." While I don't have a Cooking Chef or any other means to stir while maintaining saccharification (65C, optimal b-amylase activity), though that would be as cool as it gets, static, prolonged "mashes" have worked out well.
This is the first recipe I've come across actually calling for "black rye flour," Type 2500. Anyone familiar with this, what are its characteristics? Is it a variety of rye, or is it altered in some way? Any possible means to emulate the flour here in the US?