Before storing it, and mould

Store it, and deal with mould

The manual, and Kamado Joe's cool-down video for the latch.

1. Make sure the fire is completely out and every surface is cold.
2. Empty the ash drawer.
3. Leave the latch open, to spare the gasket.
4. Cover the grill and keep it in a cool, dry place.
5. If mould or mildew shows inside later, run a clean burn, then brush it out once cold.