Additionally, the bowl and blade of the food processor should be chilled in a refrigerator before using. Some mechanical stuffer is required. Some grinders have sausage stuffing attachments that can be used for occasional projects. Small commercial stuffers are available from restaurant supply stores at a reasonable price. No matter what type of stuffer is used, it is important to be sure to pack the meat mixture into the stuffer without creating air pockets.
Air pockets result in air bubbles in the finished sausage.
Use the largest stuffing tube that works with the casing being used so that the meat mixture is not heated by forcing it through too small of a tube. Sufficient casing is slipped onto the stuffing tube and a knot tied in the end before the stuffing starts. Push the mixture into the casings at a steady rate so that the sausages are even in shape and texture. Inspect the surface of the individual sausages and puncture a small hole with a very sharp skewer over any air bubbles. Some recipes call for evenly puncturing the entire surface of the casing.