I mashed the whole grain bill @ 150º for an hour, with 4 gallons it filled my cooler just about to the top. Let the temp drop to 120º put a few handfuls of grain on top of the mash. I put some foil and a dinner plate on top to keep the exposure to air down, put on the lid and let it sit 24 hours.
After 24 hours the temp was still above 100º.
I was expecting a disgusting reeking mess, when I opened the mash tun but, it smelled pretty good.
The top of the mash was just starting too get scummy, scrapped off maybe a tablespoon of crud. Then sparged and boiled as usual.
The wort was nice and sour no nasty smells or tastes. It might actually be too sour.