I'm trying to sterilize some dirt that I think might have harmful bacteria in it. My goal is to get the temperature above 140°F for about an hour or two to kill off the bacteria. I initially planned to use a blue 55-gallon plastic water barrel and rely on heat from the sun, but I checked this evening and the dirt is only reaching about 110°F. I've mixed in around 3 gallons of coffee grounds to help kickstart the process, but that doesn't seem to have worked well. I've also tried mixing the dirt like a compost tumbler, but I'm not sure if that's helping either. I really only need to achieve a few hours of heat for sterilization. Does anyone have suggestions on how to increase the dirt temperature, aside from using an oven?
1 Answer
The coffee grounds don't really help with sterilization directly; they're more useful for composting. Since you're using a whole barrel, try spreading the dirt out in thinner layers to let the heat penetrate better. It might help if you can put it out in direct sunlight for a while, or even consider using some kind of heating element that won't just cook the outer layers. That should help get the temperature up!
Good point! Spreading it out really does sound like it could make a difference. I'll give that a shot next time I check the temp.