Welcome to the world of cold smoking!
There are 2 key factors to a successful cold smoke. The first is keeping your coal base going and the second is the color of the smoke.
It's important to note that depending on the ambient temperature (room temperature) and weather conditions, cold smoke may not always be possible. Cold smoke usually runs about 30-60°F hotter than the ambient temperature.
STARTING AND MAINTAINING YOUR COAL BASE
Start by adding 2 charcoal briquettes (or similar sized charcoal chunks) to the smoke box. Add 2-3 chunks of desired wood on top of the Charwood in the smoke box. These chunks should be similar size to the charcoal briquettes. Insert the smoke box all the way into the grill and open the damper by turning the handle counter-clockwise a quarter turn. Open the lid of the grill and select SET TEMP from the main menu. Rotate the dial and select 220°F as your temperature. Let your grill run through startup and run for another 10 minutes to get your coal base started (keep your lid open). After 10 minutes, select SET TEMP from your main menu and roll back the menu until you see FAN ONLY and choose fan speed 5. Close the damper, open your smoke box and add a few more chunks of wood. Reinsert your smoke box into the grill and open your damper. Keep your lid open for another 9 minutes or add a pan of ice into the grill to cool it down. Depending on what you are cold smoking, you can put it in when you reach your desired temperature during the last 9 minutes. For example: Once the grill temperature is under 90°F, you can insert cheese. Once you insert your food, close your lid.
Note: You can also manually start your coal base with a torch. To do this, remove your smoke box and add charcoal and raw wood. Use your torch to start the coal base until it has red glowing embers. This can take a few minutes. Once coal base is started, insert your smoke box into the grill and choose FAN ONLY from the main menu. You will want to check your coal base every 10 minutes to ensure you still have a good coal base and check to see if you need to add more wood.
NOTE: To check the smoke box, you will first have to close the damper. After re-inserting the smoke box, you will need to open the damper. What you are looking for is that the coal at the bottom of the pile has red embers that are still glowing and the new wood on the top is raw wood. If the top wood chunks have turned black, it is time to add some more wood chunks on top.
If you do not see any embers, your coal base has likely gone out and you will want to redo the startup cycle. As long as you have a good coal base and continue to add wood as needed, this coal base can provide a perpetual smoke for several hours.
The smoke color is the key to having a good smoky flavor instead of a bitter smoky flavor. During the startup cycle you are likely to see 2 colors of smoke. White (dirty smoke) and silvery blue (clean smoke). When the wood and pellets first start to burn, they put off a white smoke. Once they get to a higher temperature (650-750°F) and get enough airflow, the smoke will start turning to a silvery blue color. See section on wood burning life-cycle for more information. After the low smoke startup cycle is complete, if your smoke looks more white than the silvery blue color, there are a few things you can do to achieve the silvery blue smoke. The first thing is check your grill is clean. Leftover oils or drippings will cause bad smoke if they get hot. Second thing to check is the wood you are putting into the smoke box, if the wood is wet or too green, it will cause dirty smoke. Third thing to check is the airflow. The smoke box needs airflow to be able to burn clean. To allow more airflow into the smoke box, first ensure that the damper is open. Then adjust the smoke box by pulling it towards you a quarter inch. (One way to tell if you have gone too far is if you are looking down on the smoke box, you will see the bracket connecting to the door, but you shouldn't see the smoke box gasket. ) Wait for a few minutes and see if the color of the smoke has changed. If needed you can continue to pull the smoke box out up to an inch. (NOTE: you will be able to see the gasket if you pull the smoke box out an inch.) The last thing to check is the amount of raw wood you added to the smoke box. If you add too much, your coal base won't be able to light it and will cause dirty smoke. It is best to have equal amounts of raw wood, blackened wood and lit charcoal. Once you achieve the silvery blue smoke, you will want to adjust your smoke box back to the quarter inch position. By adjusting the position of the smoke box, you are allowing more airflow into the smoke box to get you the better quality smoke.
WOOD BURNING LIFE-CYCLE
There are 3 steps in the cycle that we want to highlight. First you have your raw wood chunks. Second you have your unlit charcoal. Third you have your hot charcoal. The way to create the best smoke is to get your wood up to 650-750°F. By running through the startup process and running your grill for 10 minutes, you will build up a hot coal base that is critical for producing the silvery blue smoke. The unlit charcoal/blackened wood and the raw chunks are there to keep the burning process going. As you continue to add raw wood to the smoke box, the coal base will heat up the raw wood, and start to blacken it. It will also heat the blackened wood to a point where it becomes the new coal base as the old coal base burns out. Airflow is critical to keeping the burning process going and allowing the wood to burn clean.
USING THE SMOKE BOX ON OTHER TEMPERATURE SETTINGS
The smoke box is much easier to use in other temperature settings than it is for cold smoke. To use, fill your smoke box with at least 2 pieces of charcoal and 2 pieces of raw wood, both of these should be about the size of a standard charcoal briquette.
NOTE: You can put more wood up to the brim of the smoke box. Do not overfill the smoke box. It will not close/work properly if overfilled.
Insert the smoke box into the grill with the damper open. Set your desired temperature on your controller and go through the startup cycle. Leave the damper open for 10 minutes after the startup cycle has finished. After the 10 minutes close the damper and open the smoke box to check your coal base. Depending on how much wood you put in on startup will change the need for more wood. Check the smoke box every 10-30 minutes to ensure your coal base is still going.
NOTE: The damper must be in the closed position before you open the smoke box. If the embers in the smoke box go out, you can open the damper for 10 minutes to relight. See the Cold Smoke section for more information on Starting and Maintaining your coal base.
Head back to the Smoke Color section on how to get the perfect smoke during your cooking on any temperature setting.