Per ananda's recommendations (which I may not have followed perfectly), a couple days ago I made a mash at 65C / 149F for 3 hrs, which tasted very good, better than a mash at 73.5C for 3 hrs. Then I froze the 65C mash for 2 days, because I had to leave town. Tonight I thawed it, and it still tasted as sweet as it did when I made it.
Hey Andy, my books are still in transit, but I read online about a stepped escalation of temps, such as: begin at 60C and escalate to 70C over the course of 3-4 hrs. Do you think that matters for flavor? I have not run all of the potential variations...