Originally Posted by Andy M.
I use a chimney and newspaper then place the burning charcoal on one side of the grill. A chunk of hickory (or other wood) goes on the coals. A pan of water goes next to the coals. The item to be smoked goes over the water. The vent in the lid is opposite the vent in the bottom so smoke has to travel across the food. I have a probe thermometer in there and watch the temps and fiddle with the top and bottom vents to try to maintain a fairly constant temp.
My current thought is that I'm using too much charcoal. I'm going to try less next time and see if that helps.
Perhaps you are starting off with too many lit coals.
I load the big Weber chimney full, light it, and only when the bottom fourth of the coals in the chimney are lit I dump the entire contents into the kettle. So I basically end up with roughly 15 lit coals sitting on top of the rest of unlit coals in the kettle and bring it up to temp using only the bottom vent. Top vent is almost always wide open. With the coals burning down very slowly I get a few hours worth of smoking time.
The water in the pan makes a good heat sink and should keep temps pretty steady for the duration of the cook. I don't use a water pan but use a couple of bricks to keep the charcoal contained to one side of the kettle.