Lean muscle tissue (meat) contains several proteins that serve different functions.
Myofibrillar proteins (muscle fibre proteins) are responsible for muscle contraction and are abundant in lean meat. Myofibrillar proteins are very important because they are salt soluble; meaning that they can be dissolved with salt and are extracted from the lean mixture through mixing and agitation. In sausage making, these proteins provide very stable binding qualities that results in improved fat and moisture retention, texture, appearance and yield.
Sausage making is a continuous sequence of events in which each step is an integral part of the whole; and mixing is no exception. Fat released from fat cells (damaged during grinding), tends to separate from the sausage mixture unless it is tightly bound. Mixing ensures that the myofibrillar proteins that are extracted from the lean meat are drawn to the fat and moisture when the batter is heated. The resulting protein layer minimizes the loss of fats or moisture during the cooking process.
The proteins are best extracted at a lean meat temperature between 4°C to 7°C. Therefore it is important to keep the temperature of the batter cool for as long as possible to ensure maximum protein extraction.As mixing causes friction, thereby heating the batter, we can control temperatures by starting the process with meats at approximately 1°C to 2°C. Minimal handling and sharp grinder plates will aid in maintaining these temperatures prior to mixing. If the meat warms during grinding, place it back in the refrigerator/freezer until it has cooled again.
During mixing, the temperature can be controlled by the addition of ice cold water. The water temperature is achieved by placing ice cubes in the water, and then straining the ice off just prior to use. We want to eliminate any ice in the batter as these will create "pockets" inside the sausage after the cubes thaw, providing a place for fat and water to escape.
- Place lean meats in the mixer- turn for a few rounds.
- Add the measured salt to the lean meats- mix until there is a strong meat balling effect through protein extraction.
- Add the fat- mix until it disperses throughout the batter.
- Add 1/2 of the spice and 1/2 of the water- mix until dispersed.
- Add the remaining 1/2 of the spice and water- mix until fully bound and the batter turns to a dull sheen.
- If a binder such as milk powder, toasted wheat crumb, or rice flour is used, add it to the batter just before mixing completion. These binders will cause the batter to warm rapidly and do not assist in protein extraction.
- Be careful not to mix above 12°C as this will cause the proteins to denature and binding capabilities will be lost.
- Remove the batter from the mixer and stuff.
Note: The same steps can be completed by hand in a mixing tub by tossing the meats over each other, ensuring not to squish and smear the proteins between your fingers.
Although there are several methods to making a sausage batter, the above example ensures optimal protein extraction, colour retention and mixture stability.