Using wood chips for a smoker can add some great flavours to your BBQ foods. Even when recipes don't specifically call for it, you can always add wood to get that extra flavor boost. Wood chips are pretty easy to find, but there are also wood chunks and wood pellets as options.
Wood chips burn relatively fast since they're small and thin. If you want a quick burst of smoke and you're only grilling for a short time, use wood chips in your smoker. You might need to add a handful or two during grilling if the chips are getting used up too quickly (this is when hinged cooking grates come in real handy - just flip up the side and drop in more wood).
Wood chunks are heavier & thicker then chips or pellets, ranging in size from 1" to 2" pieces, to chunks that are as big as a fist! They're great for when you want to smoke something for a long time, like those 'low and slow' cookouts that create tender roasts and ribs. Often you'll only need 2 to 4 pieces (depending on the size) for a good amount of smoke.
Wood pellets aren't all that commonly used, at least not around here.
Pellets are basically wet sawdust compressed into thin rods and then
cut or broken into pellets. Make sure you use food-grade pellets!
They shouldn't have any glues or binders in them (most people don't like
the taste of chemicals on their food). Do not, I repeat, do not
use wood pellets that were created for home heating.
Food-grade wood pellets are sometimes a mixture of woods. We've used them only a few times and found them to be really inconsistent... some of the pellets we used crumbled too quickly while others were hard to keep burning. A friend swears by pellets but he also refuses to tell us the brand he uses. He's weird like that. One of the big draws of using pellets is that they don't need to be soaked first, like wood chips and chunks do. Pellets burn pretty quick and so are more suited to shorter cook times.
Whether you choose wood chips for your smoker or you decide on chunks, you'll need to soak them first (remember, pellets should not be soaked or they'll just revert back to sawdust!). Water is usually used - but it doesn't have to be! You can soak the wood in juices (like lemon or apple juice), wine, beer, or whatever flavor you want the wood to add to your food. The rule of thumb is: the stronger the flavor, the less time you need to soak the wood (as a guide, we soak wood chips for about an hour if we're just using water, about 4 to 5 hours when we use lemon juice, and just 15 to 20 minutes if using wine).
Remember, more smoke is not better (ashtray-flavored food, anyone?). Start with a small amount of wood since you can always add more next time. Be sure to drain the wood before using it - it should be damp, not wet. Here are a few pointers on the best wood for BBQ depending on what type of meat you'll be grilling up... and of course some general BBQ tips for cooking up some great barbecue.