A professional who cleans or replaces stones in carbonating-stone assembly used to introduce carbon dioxide into tanks of beer. Respnsibilities include:

• Carries stone to work area.
• Climbs into aging tank and disassembles frame and stone assembly, using handtools.
• Examines stone to detect faults or breaks.
• Scrubs stone, using brush and cleaners.
• Reassembles stone in frame.
• Discards faulty stones.