While there are numerous ways to make kibble and other dry pet food products, the most commonly used process is extrusion. This process was adapted for making pet food in the 1950s based upon technology used in the production of puffed breakfast cereals. The diagram below on Making Dry Pet Food by Extrusion illustrates the process.
Making Dry Pet Food by Extrusion
- Ingredients are brought together in a mixer. Dry ingredients may be ground prior to incorporation with wet ingredients. Once mixed together, they form a moist dough.
- The dough is heated in the preconditioner prior to introduction to the extruder.
- The extruder, similar to a giant meat grinder that is heated, is where the primary cooking phase for dry extruded pet food products occurs. The dough is cooked under intense heat and pressure as it moves toward the open end of the extruder. At the end of the extruder, hot dough passes through a shaping die and knife (similar to the action of a meat grinder) where the small pieces expand rapidly into kibble once they are under standard air pressure.
- Kibble is dried in an oven until its moisture content is low enough to make it shelf stable like a cookie or cracker.
- The drying oven is followed by a cooling phase.
- After cooling, kibble may pass through a machine that sprays on a coating, which is generally a flavor enhancer.
- Packaging (bags, boxes, pouches, etc.) is filled during the last step to precise amounts to meet the weight advertised on the label. The final result is finished pet foods or treats.