It's pretty shocking when the rip off the cover off your cooker in spring to discover the interior is covered in white fuzz. Weber Smokey Mountain (WSM) owners are especially vulnerable to this jolt.
That's because mold loves moisture and grease. When you are done with a cook, superheat your cooker. Add fresh coal if necessary. Burn off all that food residue. Scrape grease off the interior with a plastic putty knife regularly, especially if you don't plan to use it for a while. Store your cooker with the vents open and in a dry place so moist air is not trapped inside. On the WSM, remove the side door.
One of the major causes of mold is your cover! It traps moisture that causes mold and rust. If your grill or smoker is tight and well painted or stanless steel, don't use a cover! If you have a cheap unit with spraypaint, or a unit that leaks like the lid on the Weber Smokey Mountain, then you must use a cover. Otherwise, leave your cooker nekkid. I will not fall apart.
If you do get mold, and you have a ceramic cooker, do not use chlorine or solvents, do not powerwash, and do not use a metal scraper or a wire brush on the ceramic parts. Heat is your only tool. If you have a grill or smoker made of metal and you have a mold infestation, here's what to do:
1) Discard any charcoal, lava rocks, ceramic briquets, or other porous materials.
2) Fire it up as hot as possible to kill it and burn off all grease and mold. Use a double load of charcoal. If you try to scrape it off or powerwash first you might inhale a lot of spores and have an allergic reaction, and you will still have a lot of mold on the floor.
3) Let it cool and now scrape and scrub everything in sight with a wire brush or a pressure washer. Remove parts and scrape or pressure wash them. The only desirable grease is elbow grease.
4) Then wash everything down with soapy water. Then rinse thoroughly.
5) Finally, fire it up one last time to burn off any mold, grease, and soap residue. You're now ready to cook. Click here to learn more about setting up your Weber Smokey Mountain, setting up your charcoal grill, and setting up your gas grill.