[Klegane]

Hi everyone; a little disclaimer first,

[I was just hired as an assistant distiller (!) and I'm trying to get as much education as possible without driving the master distiller/owner totally nuts with my endless questions. I was hoping you all could help me keep the mash tun from stopping up while lautering. Since this has nothing directly connected to distillation, and everything to do with brewing equipment, I figured this forum might be a good resource to check with.]

https://imgur.com/a/nrN16bY

So we fill this mash tun with 170° water and lots of raw, rolled, and milled barley, toss in some enzymes, and cool the mash to about 110° before aerating and pumping the mash to a fermenting tun. This is where production sloooooows down, since even with an electric pump the mash sticks like crazy. My boss says it's not sticking because we can get the flow going again with a boat oar, but folks, I've brewed a bit before and wow... This. is. rough.

My two questions are:
I've been reading a lot about grain beds and mash beds, but we've been running this immersion impeller to stir the mash from beginning to end of operations. Should we be turning it off to sparge/lauter and maintain a grain bed?

Is cooling the mash after adding the enzymes causing glutenization to gum up our hoses? We have to cool the mash at some point before fermenting so the yeast doesn't die... What about that?

Is there something else that I'm not thinking about due to being green? Last time, we had to stop pumping the mash over 6+(!) times to burp the mash with a boat oar. Even then, our flow rate was abysmal.

Any insight on this stuck lauter would be very, very appreciated. Thank you in advance.