I've never tried fermented tobacco so I set up an experemental chamber consisting of:
1- old dish washer destined for dump
2-1 old outdoor light fixture {the motion detector kind w/out motion detector, disassemble so your only useing 1 side if double fixture, leave base for mounting, leave metal shroud for bulb}
3-60 watt bulb
4-insulation for exterior {I'm using old shipping blankets} would recommend ac duct insulation
5-12in. deep frier thermometer
I removed bottom rack ,and bent wires over in top rack to give flatter surface and more space, drilled small hole in one side about centered top to bottom, front to back to accomidate wire for light fixture, screw fixture to side.. add water to bottom of dish washer and plug drain hole {plastic and rubber bands}. Mine has another 3/4 in.hole in front bottom, I fill to this level, just before starting to leak. Aim light fixture straight down to heat water and cause evaporation. The bottom hole allows air to enter from bottom and top of door has vent that I contol with rag to make smaller or bigger, also allows for insertion of temp gauge. I lay an old towel in tray and pile tobacco and cover with another cloth or towel. check morning and evening. Mine has been maintaining about 120 degrees +, If feels to dry sprinkle a small amount of water on top cloth, if to damp uncover top cloth. By turning once or twice a day my tobacco has maintained a not to wet, not to dry feel to it. Will be interesting to see if I can tell the difference in a week or so. I have mine located under covered back porch. Have had no problem with heat build up where fixture mounts to plastic side of washer.