Grinding
Before grinding, it is important to trim the meat of glands and sinew. Although the process of “cleaning” the meat of these items makes more work, it will help produce a better sausage.
The screw is the main working part of the grinder. It steadily pushes meat down the shaft and toward the blades. The blade and plate are what do the actual grinding. The key to doing a good job grinding is to use sharp blades and plates that match. The blade is a small, cross-shaped piece with a sharp edge on each arm that rotates against the plate (also called the die).
The sausage may be ground twice, especially if two meats, such as a fat meat and a lean meat, are being used. The fist-size chunks of lean meats are first ground by running them through a 3-6 mm grinder plate while fat trimmings or fatty tissues are reduced through a 6-9 mm grinder plate. Grinding improves the uniformity of the product by distributing the ingredients and making the particles the same size.
Ideally, meat should always be chilled between 0-2ºC for a clean cut. Since refrigerator temperatures are roughly 3-4º C, meat should be placed in a freezer for about 30 min just before grinding.
Mincing
After grinding, the meat is minced in to a very fine particle size for easy protein extraction. Proteins have the function of binding the water surrounding fat droplets and keeping them dispersed.
Mincing mechanically disrupts these protein structures and enhances the sensory tenderness of the finished product. The disruption of cellular membranes allows a rapid distribution throughout the meat particles of subsequently added salt (usually around 1% of the meat weight in a mince or a hamburger patty) or other spices, flavors, or additives for fresh sausage manufacturing.
The time of mincing, the lean meat should be chopped for a sufficient period, normally not less than 6-8 minutes. Chopping is then continued until the batch is thoroughly chopped.
Manufacturing of meat sausage: Grinding and mincing
