Aim for hardwoods that feature less intense flavors. Oak is conventional—easy on the wallet, easy to find, and burns slowly thanks to its density (honorable mentions: hickory and pecan). However, the flavor profile isn’t that big a deal; pizza doesn’t cook long enough to absorb much smoke flavor, so pick whatever wood is easiest. Never burn soft wood (especially pine) or treated lumber. Soft woods are filled with resinous sap containing chemicals that can cause damage to your respiratory system, and burning treated lumber can cause exposure to toxic ash and smoke.