A typical cooking schedule for smoked meats includes most or all of the following steps:

Conditioning, Drying, Smoking, Color set, Cooking, Finishing.

Many variations of this six-step cooking process are commonly used, with certain steps added or deleted. But the basic purposes for each process should be understood before developing or modifying cooking schedules. Also, when dry-bulb and wet-bulb setpoints are established for any step in a cooking schedule, the strong effect of wet-bulb temperature on product surface conditions and heating rates must be taken in consideration.

Conditioning

The objective of the conditioning step is to create uniform surface conditions for the product load before it is cooked and smoked. In its most basic form, a conditioning step may simply be showering the load of product before cooking. Another effective conditioning method is to run the first stage of a process as a warm, high relative humidity step. A warm, high humidity conditioning step will create a thin layer of condensate on cool product surfaces, resulting in uniform surface conditions for the entire load. An example of a conditioning step would be 15 minutes with a 110°F dry bulb and a 100°F wet bulb.

Drying

The objective of the drying step is to uniformly dry the product surface to a desired moisture level so smoke will be uniformly absorbed and the desired smoked color will develop. More smoke will be absorbed into a moist product surface than a dry product surface. For this reason, if a darker surface color is desired, the drying step should be shortened. If a lighter surface color is desired, the drying step should be lengthened. Longer drying steps will also minimize two-tone color formation on products cooked horizontally in an oven. The temperature setpoints for the drying step will vary greatly, depending on the type of product. Typical setpoints for a drying step would be a dry-bulb temperature of 120°F to 160°F and a wet-bulb temperature of 0°F to 120°F. If a wet-bulb setpoint is used, the humidity valve is often turned off during the drying step so no steam or water humidity will be injected. With the humidity valve turned off, the oven will try to satisfy the wet-bulb setpoint by modulating the fresh air and exhaust dampers to control the level of natural humidity (evaporated product moisture) in the oven. The use of natural humidity alone during the drying step will help prevent any undesired condensation of moisture on the product surface during the drying step, while maintaining a consistent wet-bulb setpoint from day to day and season to season.

Smoking

Either wood smoke or liquid smoke can be used to achieve smoke flavors. When wood smoke is the application of choice, maintaining hot, dry conditions in the oven will enhance the color reaction between the carbonyls in the smoke and the amines in the meat. Enhancing this reaction will promote the development of the desired smoked surface appearance. Typical setpoints during a wood smoking step would be a 120°F to 165°F dry-bulb temperature and a 0°F to 130°F wet-bulb temperature. If the wet-bulb setpoint is higher for this step than for the previous drying step, moisture may condense on the product and re-wet the surface at the beginning of the smoking step. To avoid this complication, it is a good idea to use the same wet-bulb setpoint for smoking that was used for drying. For liquid smoke application in batch ovens, the smoke is usually applied by shutting down the oven and atomizing the liquid into the oven cabinet. A liquid smoke step normally includes an atomized smoke application period followed by a short dwell time, after which the oven is restarted and the process continued. Regardless of the application time for the liquid smoke, the dwell time should not be longer than 10 minutes. Atomized liquid smoke is sometimes applied in two steps rather than one, with a short (15-minute to 30-minute) drying step separating the two applications. If this method is used, the wet-bulb temperature for the drying step should be set at 0°F to create the dry conditions that enhance smoked color development. Applying atomized liquid smoke using two short steps is often more effective than using one long step, even if the actual atomization time is the same. For example, two 15-minute liquid smoke applications separated by 15 minutes of drying time will often be more effective than a single 30-minute application.

Color Set

The purpose of the color set step is to develop and set the smoked surface color before proceeding to higher humidity cooking and finishing. During color set, hot, dry conditions should be maintained in the oven to promote the development and stabilization of the desired smoke color. Typical setpoints for the color set are 140°F to 180°F dry-bulb temperature and 0°F to 120°F wet-bulb temperature. If a process includes a liquid smoke application, it is essential that a color-set period follow the liquid smoke step to promote smoke color development and to set the smoked color immediately after it is applied. To create the dry conditions that promote smoke color development and stabilization, the wet-bulb temperature should be set at 0°F for this step of the color set. In a wood smoking process, a color-set step may not be necessary if the color has been effectively set during the smoking step. If a color-set step is included, it is a good idea to maintain the same wet-bulb setpoint used for the smoking and drying steps to prevent moisture condensation on the product surface.

Cooking

This step is used as a transition between the low humidity color-set step and the high humidity finishing step. Typical setpoints for the cooking step would be a 160°F dry-bulb temperature and a 130°F to 150°F wet-bulb temperature. For some products, this step is unnecessary.

Finishing

During the finishing step, product is cooked to its target core temperature. The wet-bulb setpoint should be set at or slightly higher than the target core temperature. For example, if the target core temperature for a product is 160°F, the wet-bulb setpoint for the finishing step should be 160°F or higher. This will reduce cooking times, improve product temperature uniformity and improve shrink uniformity. If the color has been developed and stabilized properly during the previous steps, the high wet-bulb temperature should have no adverse effect on product surface color. Typical setpoints for the finishing step would be a 170°F to 200°F dry-bulb temperature and a 155°F to 165°F wet-bulb temperature.

Summary