Pale crusts and burnt bottoms usually start with the oven, not the dough.

The stone deck soaks up liquid. Water or cleaner in the stone can turn to steam when it heats, and that can crack it.

1. Let the oven cool.
2. Scrape burnt cheese and dough off the stone with an oven brush's scraper side. Don't gouge the surface.
3. Brush the loose debris and ash out of the oven.
4. Brush the walls and clean under the doors, where crumbs collect.
5. Wipe the outside and the door handles.

A stained stone is normal. It's the stuck-on, burnt buildup you're after.

Conveyor ovens have more parts and more corners for crumbs. They need cleaning more often.

• The belt. Brush crumbs off it daily. On the manual's schedule, remove it and clean it with the cleaner the maker allows.
• The crumb pans. Empty them daily. They fill up faster than you'd think.
• The air fingers. These blow hot air onto the pizza from above and below. When their holes clog with crumbs and grease, the bake goes uneven. Pull and clean them as the manual describes.
• The fan area. Keep the motor vents clear of dust and flour.

An oven thermometer or an infrared thermometer on the deck tells you whether the dial is honest. Check it the same way, in the same spots, each time. If it's off, or one side runs hotter, the thermostat, burner or element needs service.

On a conveyor oven, check that the belt speed matches the setting. Time how long a pizza takes to go through and compare it to the dial.

• Throwing water on a hot deck to clean it.
• Using harsh cleaners inside the baking chamber.
• Loading the belt with pans hanging off the edges.
• Blocking the vents with boxes of supplies.

• The oven takes longer to reach temperature.
• Pizzas come out pale on one side and dark on the other.
• The belt slows, stops or jerks.
• The fan is loud or the oven shuts off on its own.
• A gas oven won't light, or a pilot keeps going out.
• A deck stone is cracked through.