Smoked Salt is a great way to bring the smoky flavor of your Egg to other food items that you cant (or don't have the time to) prepare on the Egg.
Creating your own smoked salt is very easy but does require a bit of time.
Start by presoaking 3 pounds of hickory chips until fully saturated, at least an hour - all day would be better. Hickory is preferred because it creates a heavy dominate smoke and you want the strongest smoke you can get. You are looking for three things from the soaked chips:
The smoke itself is the flavoring agent for the salt.
<2> The moisture given off by the wet chips acts as a carrier to bond the smoke to the salt.
<3> The wetness of the chips will expand the timeframe that the chips will give off a heavy smoke.
After getting the lump going, put about 2.5 pounds of the soaked chips directly on the lump. Be sure to let the chips drip in a strainer for at least 10 minutes before placing them onto the lump. (The lump should be almost almost completely covered by the hickory chips.) Insert your platesetter in the legs up position. Take the remaining Hickory chips (about a 1/2 pound.) and place them into a large pan then fill the pan full of water. Carefully place this pan onto your platesetter.
As the water pan heats up it will generate steam, which you want as a catalyst for bonding the smoke to the salt. When the pan boils dry, the chips in the pan will then smolder for additional smoke. I recommend a temperature of about 250F as this will generate stem and also maximize the burn time of your fuel.
This setup will immediately start giving off billowing clouds of thick smoke. Personally I do this at night just to avoid the interest that this much smoke can create. No need to have firefighters shaking their heads when you explain you are cooking salt. (Having your wife shaking her head will suffice!)
One of the keys to getting the salt to absorb the smoke is "surface area". I recommend using disposable aluminum pans, and spreading your salt out in a thin layer across the surface of each pan. Approx 3/16th's of an inch is perfect.
Since the key here is quantity, you can stack these trays vertically on the grill by using something to create a space between them for the smoke to infiltrate. I found that the lift-grids you find in toaster-ovens are perfect as they provide a couple of inches of separation between each tray for air circulation.
Kosher Salt and Sea Salt are recommended for best results, and iodized table salt is best avoided. Remember you are smoking the salt, not cooking it. As the melting temperature of salt is over 900F, you don't have to worry much about getting too hot - but the lower the temp the longer your lump will last. As spices go, salt is a really impervious material and is probably the most difficult spice to smoke - fortunately it is also hygroscopic and wants to absorb moisture - this is the property that we are taking advantage of in order to get it to absorb the smoke.
As the salt starts to absorb the smoke-laden moisture it will start to change color taking on a brown-caramel like hue.
Since it's the salt crystals on top that are most exposed to the smoke and most take in the flavor it is important to stir the salt in your trays. When you stir the trays you will notice how the salt underneath does not get the same benefit as the salt that was at the surface. Do this every four hours until you are satisfied with the results of your smoke. I find that you need at least 16 hours for a good consistent smoke and 24 hours is even better.
One thing to be aware of is that the steam you are generating will sometimes condense on your upper vent. When this happens it will sometimes drip back into your grill and onto your salt. If you have a grill with a particularly "crusty" dome, you might find dripping to be an issue in other places too. The best solution here is to have a top "Cover Tray" that will catch any such drips. I found that with a clean dome the problem is minor and the few drops that did occur left dark spots in the salt, but since it also welded those crystals together they were easy to lift out and discard.
picture illustrates that you can fabricate a tray out of Aluminum foil if
you desire, this approach allows you to customize your tray size and shape
to that of your grill..
After 16 hours the salt will darken up rather nicely. If you put it into a canning jar while it is still hot, it will draw a seal due to the cooling. This will help the salt keep it's flavor for months at a time. (This picture shows Kosher Salt and Smoked Kosher Salt for a color comparison:)
The above arrangement with 1 16-inch aluminum-foil tray and 2 12-inch Aluminum-foil pans resulted in a yield of about 4 1/2 pounds of salt. The squarish jar (with the darker lid) contains Sea Salt whereas the other jars contain Kosher Salt:
It is highly recommended that you store your smoked salt in air-tight containers until needed. This will help preserve the smoked flavor and extend the lifespan of the salt.