A typical smoked meat production process usually includes most or all of the following process steps: conditioning, drying, smoking, color fixation, pre-cooking, and cooking. In actual applications, these six process steps can be combined in many forms, and specific steps are often added or deleted, but for smoked meat manufacturers, the basic functions of these process steps should be understood to optimize the production process.
01 Conditioning
The purpose of conditioning is to form a uniform surface on all products in the oven before smoking and cooking. The most basic form of conditioning process is spraying, which can also be used to clean dirt on the surface of the product; another effective conditioning method is to use warm air and high relative humidity in the first step of entering the oven. This process step is also called flushing or heating. This warm air and high relative temperature will establish a thin layer of condensed water on the cooler surface of the product to complete the uniform product surface conditioning of the entire oven product, such as using a dry bulb temperature of 43°C and a wet bulb temperature of 37°C for ten minutes.
02 Drying
The purpose of the drying step is to form a uniform dry product surface to ensure that the product surface has the desired moisture content during the smoking process, which will affect the product's absorption of smoke during the smoking process and form a uniform desired smoke color. During the smoking process, a moist product surface absorbs smoke better than a dry product surface. Therefore, if the product surface requires a dark color, the drying step should be shortened; if the product surface requires a lighter color, the drying step should be extended. Longer drying steps can also reduce color inconsistencies on the product surface, especially when the product is laid flat on the smoking cart for production (such as some fish products). The temperature setting of the drying step also varies with the type of product, and typical drying temperature settings are 48-71°C dry bulb temperature and 0 to 48°C wet bulb temperature.
If the wet bulb temperature value is set in the drying step, the humidity control function (such as steam humidification) will be turned off, resulting in no steam or moisture entering the smoker. When the humidity control function is turned off, the smoker needs to adjust the fresh air and exhaust dampers to control the natural humidity of the product in the smoker in order to achieve the wet bulb temperature set point. Whether in daily production or in the presence of seasonal changes, natural drying (without humidification) will reduce moisture condensation on the product surface and can also ensure a stable wet bulb temperature.
03 Smoking
The smoking step can be natural smoking or liquid smoking. Keeping the smoker hot and dry during natural smoking will cause the carbonyl compounds in the smoke to react with the amino compounds in the meat to undergo a Maillard reaction, which will form a tea-brown color on the product surface, but excessive surface drying will also reduce smoke absorption and extend the smoking time. Typical natural wood smoking temperatures are 48-73°C dry bulb temperature and 0-53°C wet bulb temperature. If the wet bulb temperature setting for smoking is higher than the setting of the previous drying step, moisture will condense on the surface of the product and re-wet the surface of the product at the beginning of the smoking step, so it is best to use the same wet bulb temperature setting to avoid this.
When using liquid smoke in a batch smoker, the smoke liquid aqueous solution is sprayed into the smoker by atomization. The liquid smoking step usually includes an atomization stage and a condensation stage, and then the smoker proceeds to other steps. Regardless of how long the liquid smoke is, the liquid smoke condensation time is preferably no more than ten minutes. Using two shorter liquid smoke steps is more effective than one longer liquid smoke step, especially when the atomization time is the same, the intermediate drying process should be set to 0 wet bulb temperature so that the damper is open to create a dry environment to promote color development. For example, 15 minutes of liquid smoke, 15 minutes of drying, and 15 minutes of liquid smoke are more effective than a single 30-minute liquid smoke process.
04 Fixation
The purpose of the color fixation process step is to generate and fix the smoke color on the product surface before the high humidity cooking process. During this step, the hot and dry environment in the smoke oven should be maintained to generate and stabilize the desired smoke color. Typical color adjustment temperature settings are 60-82℃ dry bulb temperature and 0-49℃ wet bulb temperature. If the process step includes liquid smoking, the color fixation step must be performed immediately after the liquid smoking step to generate and fix the smoke color. In order to generate a dry environment in the smoke oven, the damper needs to be opened and the wet bulb temperature can be set to 0. In natural smoking, if the color generation in the previous smoking step is already very good, then the color fixation step may not be necessary, but the same or slightly higher dry bulb temperature setting during the necessary exhaust process after smoking can also play a role in color fixation. If the color fixation step is used, it is best to set the same wet bulb temperature to prevent moisture condensation on the product surface.
05 Pre-cooking
The pre-cooking step is used as a transition from the low humidity color fixation step to the high humidity cooking step. Typical temperature settings are 70-85℃ dry bulb temperature and 54-64℃ wet bulb temperature. Some products do not need this step and can be omitted.
06 Cooking
During the cooking step, the product will be heated to the desired core temperature. In this step, the wet bulb temperature should be set to the desired core temperature or higher. For example, if the desired core temperature of the product is 71℃, then the wet bulb temperature should be set to 71℃ or higher, which will help reduce the cooking time, enhance the consistency of product temperature, and enhance the consistency of product weight loss. If the color has been generated and fixed in the previous step, cooking at a high wet bulb temperature will not affect the smoke color on the surface of the product. Typical temperature settings are: 76-90℃ dry bulb temperature and 68-77℃ wet bulb temperature.
Summary
In today's meat processing industry, thousands of different smoked meat products are produced every day using a combination of the above process steps. If everyone uses the same process steps, we cannot develop products and enrich the market variety through specificity. If the above is used to develop or optimize the cooking and smoking processes of a product, then a successful and more stable process should be achieved.
