I'm planning on brewing a Scottish ale (80/- export) this weekend and am planning on mashing at 158 F. I calculate the strike water to be ~172 F (using beersmith). This would be as high of a mash temp as I have used. I don't expect any problems , as I haven't heard anyone else mention anything, but the thought crossed my mind. At what point do you have to start being concerned about denaturing the enzymes with a high single infusion mash? I've always added grain to water to reduce dough balls, and I guess that could make a difference. I'd also guess the time spent at the high temperature would play a big role.
Has anyone had an issue with mash efficiency at higher mash temps?