Sausage making is one of the oldest forms of food preservation and has become an art form over the centuries. It can provide a means of converting less tender, lower grade trimmings of meat into value-added products that are flavourful, attractive, and affordable. Smoking of sausage products has been developed to provide a variety of colours, flavours, and aromas while limiting oxidation, which enhances shelf life by. Although smokehouses can vary from basic homemade to commercial grade ovens, the smoking process is the same and should include the five fundamental steps of reddening, drying, smoking, cooking, cooling.
- Reddening takes place at 35% relative humidity and a smokehouse temperature of approximately 50° C. This step warms the sausage, stabilizes the cured color and prepares it for drying.
- Drying should be completed at 0% relative humidity and a smokehouse temperature of approximately 60° C. Moisture evaporates as it moves from the mixture to the surface of the sausage. The casing prevents the loss of dissolved protein and causes the formation of a protein skin on the outside of the sausage- inside the casing. Once cooked, this protein layer will give the sausage its characteristic and appealing “Snap” or “Bite”. Drying also prepares the sausage for smoking. Optimum drying makes the product feel sticky/tacky thereby creating a surface that smoke particles will adhere to. The smokehouse should be vented during this step to allow excess moisture to escape.
- Natural smoking is done at a temperature of approximately 60°C – 70° C. If the previous drying step was excessive, 35% humidity can be added (even by placing a pan of water in the smokehouse) to provide moisture for the smoke to adhere to. Hardwood chips or sawdust produce the best smoke and can be placed dry or wet depending on the smoke generation source. All smoke should be evacuated after the desired colour has been reached. This will prevent streaking on the outside of the casing during the cooking step.
- Cooking improves the texture and palatability of sausages. By cooking the product to an internal temperature of 71°C, harmful microorganisms are destroyed, extending the shelf life and enhancing food safety. Cooking can be done at a relative humidity of 40 – 50% and an internal smokehouse temperature of approximately 80°C- 85° C. Maintaining a suitable humidity is essential in the cooking process because moist air contains up to six times more heat energy than dry air, cooking more efficiently and evenly.
- Showering or soaking the sausage in cold water will stop the cooking process and eliminates the risk of protein denaturing or fat separation due to excessive internal temperatures. Showering also cools the product rapidly which reduces casing wrinkle and moves the product through the food safety danger zone very quickly. Showering should cool the product to a final temperature of at least 40° C where it is then put in a cooler or refrigerator to further reduce the temperature to 4° C or colder.
Note: The time required in the smokehouse depends on the diameter of the meat, the heat source (electric/ gas/fire), external temperatures (if the smokehouse is outside), air flow, etc. It is important to check temperatures in different locations of the smokehouse to ensure all products reach a safe, ready to eat internal temperature of 71C.