Originally Posted by HIlife
Proteins can and will be denatured under high enough temperatures regardless of any previous activity. I don't know the temperatures that the malt proteins denature at mashing pH but I've always been surprised that they're active at all at normal mash temps.
Mash out temperatures stop enzymatic activity either by 1) moving the temperature far enough away from optimal that activity is negligible or 2) denaturing the enzymes and eliminating all activity. I haven't read enough about mash enzymology to know which it is but I would be wary about starting too high.
Ah I see. This is from wikipedia: "When food is cooked, some of its proteins become denatured. This is why boiled eggs become hard and cooked meat becomes firm."
I try to dough in as quickly as possible so I get the mash to the target temp as quickly as possible, mostly because I don't know enough about proteins, starch, and enzymes to know what's going on, specifically what "bad" things might be happening at higher temps. I only tried adding water to the grain once, and missed my temp horribly, so I quickly resorted to preheating my cooler tun with the strike water and then adding the grain (but quickly).