A professional who controls vacuum pan sugar boilers to concentrate sugar liquor and grow sugar crystals to specified size. Respnsibilities include:

• Starts vacuum pump, and opens valves to admit specified amounts of liquor and steam into vacuum pan, and water into condenser unit.
• Observes boiling of liquor through sight glasses.
• Adjusts valves to maintain specified temperatures and pressures and obtain supersaturated solution without carmelizing sugar.
• Opens valve to shock solution with panseed (powdered sugar) and start formation of sugar crystals.
• Obtains samples of solution, using proofstick, and observes grain size under microscope to determine when crystals have grown to specified size.
• Opens pan-feed valve to control growth of crystals.
• Samples solution to ensure that sugar crystals remain at specified sizes as pan fills.
• Closes pan-feed valve when pan is filled and continues boiling until solution reaches specified concentration of sugar-crystals and massecuite.
• Turns valves to stop boiling and to break vacuum seal on pan.
• Turns valve to dump sugar into mixing tank or crystallizer.
• Washes and steams pan after dumping strike to remove sugar remaining on coils or calandria.
• Records strike on station log.
• May be designated according to type of liquor boiled as Soft-Sugar Boiler; White-Sugar Boiler; or according to stage in process as High-Raw-Sugar Boiler; Remelt-Sugar Boiler.