A professional who tends equipment that mixes and churns ingredients to produce margarine. Respnsibilities include:

• Turns valves to admit preweighed ingredients, such as milk, water, and oil, into mixing vat.
• Weighs or measures additives, such as emulsifier, preservatives, salt, and vitamins, according to formula, using scale or graduate.
• Dumps additives into mixing vat.
• Starts agitator that blends and emulsifies ingredients.
• Observes temperature gauge and adjusts steam valve to maintain specified temperature in vat.
• Stops agitator after specified period of time, and turns valve to transfer ingredients to cooling unit.
• May pasteurize milk.
• May harden emulsion.
• May test milk for acidity.
• May disassemble and clean stock lines, and change filtering apparatus.
• May mix ingredients for vegetable shortening and be designated Shortening Mixer.