Rotational resistance cryogenic control system for chilling in a vacuum tumbler or agitator blender

A method for controlling cryogen flow in a food mixing machine driven by a drive shaft, said method comprising the steps of:

• providing a first measured quantity of food product into said food mixing machine;
• initiating mixing of said food product in said food mixing machine by rotation of said drive shaft and delivery of liquid cryogen onto said food product in said food mixing machine, and establishing a start time therefore;
• measuring the rotational resistance to said drive shaft as said food product is chilled and the viscosity of said food product is increased by said liquid cryogen until a maximum resistance is determined, and establishing an elapsed time T.sub.me from said start time therefore;
• continuing mixing of said food product and delivery of said liquid cryogen onto said food product until said food product has achieved forming point stiffness, and establishing an elapsed time T.sub.f from said start time therefore;
• subsequently operating said food mixing machine for a second measured quantity of food product generally equal to said first measured quantity;
• measuring the rotational resistance to said drive shaft as said second measured quantity of food product is chilled by said liquid cryogen until a maximum resistance is determined, and establishing an elapsed time T.sub.me2 therefore;
• and
• continuing mixing and chilling of said second measured quantity of food product for a total elapsed time T.sub.f2 =T.sub.me2 .times.T.sub.f /T.sub.me.