A general rule of thumb is to grind lean meats two times. Grinding reduces the diameter of the muscle fibres to the size of the chosen plate. Although the diameter is now smaller, the muscle fibres and connective tissues are still very long, and can be tough or chewy. This may be desirable in some sausages (and I demonstrate this in sausage classes to show the difference in a final product). The second grind will not reduce the diameter of the product if the same plate is used- but will cut the length of the muscle fibres, making the product tender and more palatable. The second grind is also great for sausage making as it creates more surface area of cut surfaces that ultimately results in more protein extraction. The second grind will also help mix the product together, giving it a pleasant appearance.
Our instructor recommends that lean products are ground twice. They can be ground in a course plate first (to slowly break down the diameter) and then through the desired plate the second time. Or they can be run through the same plate twice- this depends on plate sharpness and grinder capabilities.
There are two exceptions to this:
- Fats should only be ground once through the desired plate diameter to prevent warming and smearing.
- Poultry for sausage products should only be ground once through the desired diameter- unless they are very cold and plates/knives are extremely sharp.