GrillPro Cast Iron Smoker Box
4.3 out of 5 stars – based on 69 reviews
A BBQ smoker box is basically a metal box, possibly cast iron, 10 x 6 x 3 inches or there-bouts.
They are usually rectangular, but there are wedge shaped versions that sit with the pointed bottom wedged between the bars of the grill. The lid is perforated to let the smoke out.
The one in the picture left is the GrillPro 00150 Cast Iron Smoker Box - it's available from Amazon and is highly rated.
There are lots of these available and they are all inexpensive
They can be used in an offset smoker or any lidded grill to create that delicious and complex smoked flavor.
Place your soaked wood chips inside and close the lid. Put the box above your lit charcoal (or lava rocks if you use gas) and close the lid.
Bear in mind that this is an indirect grilling technique and doesn't work without the lid. The heat source will be at one end of the grill with the smoke box above it, and the meat will be above the other unheated half.
Close the lid. Once the wood chips inside the smoker box heat they will smoke profusely; this will permeate the meat, infusing it with a beautiful taste.
As it smokes it can be basted periodically with any of a variety of BBQ sauces - although you don't have to do this.
The whole process can take several hours, depending on the size of the cut of meat involved. But resist the urge to take the lid off for a look unnecessarily - indirect grilling uses lower heat over a longer period of time - it takes 15 minutes plus for the temperature to build up again.
Some say the wood chips need replacing about once an hour, others say meat gets all the smokey flavor it's going to get in the first hour.
Maybe baste the meat at the same time as you add charcoal to save opening the lid too often (thus letting the heat out and increasing the cooking time).
Here's a detailed video on the subject.