I'm contemplating a HERMS system and I have a couple of questions that I haven't seen answers to:
If I want to warm the mash by pumping wort through some kind of heat exchange (like a HERMS), how hot is it safe to make the wort? A couple of degrees higher than my desired temp? If I warm it substantially (like say 150 when I'm still doing a protein rest at 120) will I denature the enzymes doing protein conversion? If I warm it to 170 will I denature all the enzymes?
I'd like to be able to step the temperature up quickly, but I don't want to denature everything that goes through the HERMS. Speaking of which, isn't that exactly what a decoction does? Why doesn't that denature all the enzymes in the part that is heated? Is the assumption that the enzymes left in the rest of the mash are sufficient to complete the mash? Or are we assuming that enzymes don't denature right away and that the time spent at high temperature isn't sufficient to cause a problem?
Primary: Beer / Secondary: Beer / Lagering: Old beer.