I left my 1-gallon lacto starter overnight with two brew belts wrapped around it, and then a towel around that. This morning it smelled a little bit tart, but not nearly as tart as usual. I checked the temp, and it was at 141*F, so it's probably dead, right? I unplugged one of the belts, and I'll see where the temp is this afternoon and add some more grain.
I've found some pasteurization charts online, but I can't find the highest temp you can hold something indefinitely and not get any pasteurization. Also, has anyone tried to pasteurize wort just by using brew belts and insulation? I'm not sure if two would be able to get 20L or so of wort up to temp.