When manufacturing sausage products we essentially do four things; comminute meat (comminute is a fancy word for reduction in particle size i.e. grinding, flaking, dicing or chopping), season the product, manipulate proteins and shape the product. How we perform these four activities produces the wide variety of sausage products available.
Mixing plays a very important role in two of these steps — seasoning the product and manipulation of proteins. When we season a sausage we want the product to have a uniform flavor profile throughout. Improper mixing can result in one part of the batch being too salty or having too intense a flavor while another part of the batch is bland. Non-meat ingredients should be evenly sprinkled over the top of the meat while the mixer is operating. Do not add the seasoning all at one time or on top of the meat when the mixer is not operating. Mixing also achieves even distribution of the fat and lean in the product.