I'm sure that this issue has come up before, and I've searched the forum and not really found a straight answer, so I'll ask it here and hope for great help!! I do 8 gallon mashes, and my most recent cornmeal batch has not turned out so well. I boiled 5 lbs of white cornmeal into 3-or-so gallons of water, with intent to cook my 5 lbs of sugar into as well, then dump in my fermenter and fill the rest of the way with cold water. However, the entire potful has turned into a giant muddy paste. I've seen guys mention cornmeal paste in posts, but haven't really seen what they do with it. I've thought that maybe with another 4 gallons of water added, it will thin the whole thing out, and by the end of the ferment it will all settle enough to still give me 5-6 gallons of liquid once siphoned off the top. What do you guys think? BTW, I let the water come to a rolling boil before adding cornmeal, and even then it was only a little at a time.

Sounds like you were making polenta. I would use flaked corn not corn meal. Just an opinion.

This is how I do it also somewhat
don't boil it you don't want it over 155*F for converting the starch to sugars I let my water come up to temp and maintain that temp for nearly 20 min then I stir in cornmeal stick my thermometer in the mixture stirring all the while till it gets back up to temp 150 -155 add amylase stir in well let it maintain for a bit add extra sugar if you want stirring in good then let it cool till around 120 pour into fermenter let it continue to cool to 100 then bring the temp down with your extra water to 90*F pitch your yeast and stir the crap out of it to aerate at 85*F lock it off and keep an eye on it for several days it will overrun your lock if you don't leave some good head space. hope this helps. I have fermented it thick once like yours ended up it eventually settled in the bottom and left small approx. 1/3 amount of cleared to siphon off wasn't worth the effort though and dumped.