A powerful Wolf gas flame should be pure blue with a tight, sharp inner cone. If your rangetop is producing a lazy, yellow flame that leaves black soot on your cookware, the burner is suffering from an improper oxygen-to-gas ratio. In Houston’s heavy, humid air, or after a deep cleaning, the manual air-shutter beneath the burner may be knocked out of alignment, or the tiny gas orifice is clogged. A master mechanic must manually tune the air-shutter to achieve perfect combustion.