Sustaining smoke for long cook

Go with chunks.    Put them close to the fire they will be there for a long time.   Much of time through the whole cook.

What follows is a post that I saved from stike of quite a while ago that summarizes the chips/chunks discussion:

Originally posted by Stike a while ago-

“frankly, wood is wood. i use chips, chunks, barked, no bark, etc.

chips and chunks don't do anything better than the other, unless you use one like you'd use the other. meaning, use chips like chips and chunks like chunks. people win contests with either, so it doesn't affect the food. you just gotta use them "corrrectly". In the BGE chips can be mixed throughout the lump to maximize smoke during a lo and slo. your fire crawls around, so you want chips where the fire will be. you won't use up all the chips because the fire won't use up all the lump. don't screw with wet chips. in a ggasser, you wet chips to keep them from burning outright, and flaming. they can't do that in the egg. you can have a raging fire, and toss in wood, and it WILL NOT CATCH FIRE as long as the lid is shut and the airflow is dialed in. open the lid, and the wood WILL burst in to flame. shut it, and it goes out. it WILL smoke though. and that's what you want. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

chunks are fine too. you strategically put them around the lump, and maybe push one into your fire right at the start, just to make sure.

put in as many chips/chunks as you want. smoke flavor is added as long as there is smoke. that means, if you had a butt going 20 hours, and the smoke only showed up for the last hour, it'll still smell like (and taste like) smoke. it's the smoke RING that only forms in the first hour or so. and the smoke ring is color, not flavor. so don't worry about when smoke kicks in. if you like a lot, add a lot of chips or chunks.

chunks vs. chips is the same as "ford vs. chevy". much ado about nothing.

oh, as for high temp cooks. i like to toss a couple chips in sometimes when a steak is finishing. did it last night, actually. and again, no worry about flames. i tossed the wood in, shut the lid, and got some decent smoke. only when the lid was opened did it catch fire. i flipped the steak, then shut the dome, and the chips went out. that's nice to know. flames are actually bad for steak. they look pretty, but flamed is less desirable than direct heat from the lump. flame isn't as hot, either.

And with regard to smoke-the smoke ring only forms when the meat temp is below around 140*F (so cold start the better if the appearance thing is of importance)  but the smoke will adhere as long as there is smoke.