I've really tried to maintain the water bath above the 112-115 temp range to keep the mash temps elevated above 110. This evening so much gas was being pushed up through the mash that it created air/gas pockets throughout the mash and raised it's overall height by about an inch. It's become quite thick, perhaps too thick, so I added about 11 oz. boiling water and mixed it in well before returning the mash to my cooler-water bath of 123 degree water.
I'm amazed this smells much cleaner than I expected as I was expecting the full on nastiness of what I get from grain left in a mash tun for 4 days. It's really quite clean with a pure sourness to it. Very good news!