Offset Smoker And Barrel Smoker Setup And Modifications
"You gotta learn your pit just like a man learns his woman. Or you can't get nothing good outta her." Meathead
Offset smokers, sometimes called barrel smokers, are among the most popular on the market. Many of the top competition teams use expensive high end offsets. They usually have two beer can-shaped chambers. There is one long tube called the cooking chamber and a shorter one that is offset to the side and a little lower that is called the firebox. For low and slow cooking and smoking of things like ribs, charcoal goes in the firebox and food goes in the cooking chamber. For hot and fast cooking of things like steaks, coals can go in the cooking chamber right below the meat.
I do not recommend offset smokers. I strongly advise you not to buy one for less than $500.
COS have serious shortcomings that can mar meals and marriages. At the core of the problem is the simple fact of physics: Heat and smoke want to go up, not sideways. So heat and smoke exit the firebox on one side and try to go up making one side a lot hotter than the other. COS also leak smoke out and oxygen in so it is very hard to control temp. Because the metal is thin, every time you open the door all your hot air escapes and the temps yo-yo up and down. They are just plain hard to manage.
As my friend and barbecue expert Merrill Powers says, "The average guy buying his first smoker buys one of these and gets frustrated. I have purchased many of my cookers at yard sales from guys who just couldn't figure out how to make them work." If you learn a few tricks and make a few modifications to your purchase (described below), you can turn out some pretty nice food and keep your smoker out of the yard sale, but they are a real pain to keep the temp stable and even.
The most popular COS are: Brinkmann Pitmaster, Brinkmann Smoke'N Pit Professional (a.k.a. SNPP), Char-Broil Silver Smoker, Char-Broil American Gourmet, and especially the Char-Griller Smokin Pro.
The big differences between EOS and COS are design, materials, and workmanship. They add up to a big difference in user friendliness and food quality. The best EOS designs have clever convection systems, called reverse flow, to move heat and smoke evenly through the cooking chamber.
On EOS, the welds are solid and tight, and lids close and seal tightly. EOS are made from thicker steel. Thick steel keeps energy from the coals inside the firebox, making it more efficient, and thick steel in the cooking chamber heats up, stays hot, and radiates it back into the meat. This also improves efficiency and evens out the temperature within the cooking chamber.
Click here for an article with our impressions of many of the different offset smokers on the market, in all price ranges. But if you want something that looks macho and works well, get a drum smoker (right). There is even a kit that will have you up and running for under $200, and assembly is easy. You can even say "I built it myself."
How to tame your offset
If you have an offset, here are some important techniques and modifications to make, cheap or otherwise:
1) Cook with charcoal, not wood. Wood fires are too hard to manage in a COS, and they can easily spoil the meat with too much smoke, creosote, soot, or ash. A common question: "How much charcoal should I start with?" There are too many variables for a pat answer. It depends on how hot a day it is, how windy, how tight your cooker is, how heavy the metal is, how much cold meat is inside, and where the meat is in the cooking chamber (it can vary as much as 50°F from side to side). This is the craft of BBQ and it will take a few cooks for you to get the feel of your machine. Start with about 1 chimney of lit charcoal and a good thermometer and a cooking log.
2) Preheat the cooker. Start your coals and wait until the cooking chamber is up to temp before putting the meat in. This will help prevent bitter creosote from forming.
3) Add fully lit coals. Use a chimney to start the coals before you start cooking. Then, when the temperature begins to decline because the coals are fading, add only fully lit coals from the chimney.
4) Use good thermometers on both ends. Beware of the fact that the heat near the firebox can be 50°F higher than by the flue. Drill holes in the door on each end and insert a good digital thermometer probe in each to monitor the temperature on both sides of the cooking chamber. Theree are seveeral models that have more than one probe. If you must, mount a couple of Tel-Tru BQ300 Bi-metal Barbecue Thermometers with 4" stems as indicators, but use a digital next to the meat for real accuracy.
5) Don't soak your wood chips or chunks. The wood absorbs only about 5% of its weight in water and the water just cools the coals when you add it. This can cause yo-yoing temperatures.
6) Keep the lid closed. Opening the doors, either on the firebox or the cooking chamber, upsets the delicate balance of oxygen on the coals.
7) Rotate the meat. If you have meat on the left and meat on the right, they will need to be switched halfway through the cooking.
8) Learn one vent at a time. Most COS have an intake baffle and a chimney baffle. Begin by controlling the temperature with the intake baffle only and leave the chimney wide open. The intake baffle controls oxygen flow to the coals and has the most impact on cooking temperature. The chimney controls smoke in the cooking chamber (somewhat), and the temperature differential from one side to the other (somewhat). Start with the intake wide open until the chamber is up to temp, and then close it half way or more until the temp stabilizes in the 225-250°F range on the hot side. Never close the intake all the way or the fire can starve and produce creosote. Don't touch the chimney until the cooking chamber is stable for 30 minutes or more.
9) Go easy on the smoke. It is easy to ruin meat with too much smoke. Use chips, chunks, or pellets. Add about 4 ounces at a time in 3-4 doses every 30 minutes, starting as soon as the cooking chamber gets over 200°F.
10) Beware of the weather. The ambient temperature will effect the cooking temperature, and rain (or snow) and wind can significantly affect cooking temperature.
12) Protect your investment. Your COS will rust. When it is not in use, use a cover or park it in the garage. Put your car on the street. It won't rust. Sand out rust and repaint with heat resistent paint. If you use it on the interior, let it dry thoroughly before cooking. The fumes are poisonous.
13) Use a water pan. Put a grate above the coals and put a water pan on the grate. This will add humidity to the smoke and help the flavor and moistness. Don't bother putting water pans under the meat, and don't waste money on apple juice in the pan.
14) Calibrate it with dry runs. The first thing to do after you assemble your new grill or smoker is to season it and calibrate it by doing a few dry runs without food. This will burn off any manufacturer's grease, and give you a sense for how to set it up to hit the two important target temps that almost all my recipes use: 225°F and 325°F.
Of course, in order to do this, you absolutely positively must have a good digital oven thermometer. I don't care how much you spent on your grill, the bi-metal dial thermometer that came with it is probably cheap and unreliable and likely to be off by as much as 50°F. Worse still, it is in the dome, and the temp down on the grate where the meat sits is much different. Like a musician, you must master your instrument to make great food.
15) Practice. Practice. Practice. Remember the old joke about the tourist who asked the street vendor how to get to Carnegie Hall? His response was "Practice. Practice. Practice." Nothing could be more true for owners of COS. Practice without meat. Set it up and run througha cook so you can see how it behaves.
Modifying your offset smoker
You can make modifications (called "mods" by smokeheads) that will make your offset smoker work a lot better. Try the following mods to tune your pit, and scroll down to the comments section see how other clever folks have made these aggravating devices into serious smokers.
Add a deflector or a convection plate or a duct. Here's the problem: The cooking chamber is a lot hotter on the side near the firebox. And as the heat moves to the other side it dissipates rapidly. If the cooking chamber is thick and tight, the heat will not dissipate as much. But most offsets are thin and leaky.
There are several ways to help mitigate the prob.
1) Make a flap of metal that covers the opening from the firebox to the cooking chamber at an angle and bolt it on. It will deflect the heat and smoke downward. Or have a neighborhood body shop fabricate one for you. The picture here is a deflector made by Paul Salverda of Walnut, CA, from an aluminum cookie sheet and held in place by one self-tapping screw. He says the temperature diff between sides before the deflector was 40-50°F and now it is only about 10°F.
2) Cori Alcorn writes with this idea "I really want one of those convection plates but can't afford [a commercial] one and my wife wouldn't let me use one of her cookie sheets (she caught me with one of the old black ones that I thought would be fine and says it is her great grandmother's...). So instead I wrapped the cooking rack closer to the firebox with foil and then poked slits in the foil and it seems to work pretty well. My temperatures evened out quite a bit. Just thought I'd mention my solution for the po' man's convection plate."
3) Another option is to have a local body shop fabricate a baffle for you. Coleman Shelton did that and set it on bricks at right. A plate like this will radiate heat and move a lot of it over to the right side away from the firebox.
4) The ultimate solution is to fabricate a heavy steel duct like the ones built into the large commercial offset smokers and move the chimney to the side by the firebox. This design is called reverse flow. This directs all the smoke to the far side of the cooking chamber inside the duct, it travels up into the cooking chamber and across the food to exit the chimney. The duct also radiates heat up to the meat as shown in the illustration below.
Extend the chimney downward. Here's the concept: These smokers have a chimney mounted on the top. Heat and smoke travel from the firebox across to the chimney and out. If you can lower the intake of the exhaust you can move the heat across the grates at a lower level and even the heat in the cooking chamber. One way to do this is with some aluminum roof flashing from your hardware store. Roll it up, insert it into the chimney from below, let it expand to the same diameter as the chimney, and pull it down to grate height. I bought a roll of 0.0092" thick aluminum flashing 14" high and 10' long. I cut off 8" and made my chimney extension from that. Flashing costs about $8 for a roll.
Another way is to remove the chimney altogether, cover over the hole, and put in a new chimney down low as barbecue enthusiast Bruce Cook has done, above (photo credit: Bruce Cook). Here's how he described the process: "I cut a hole just below grate level and welded an elbow to the side of the pit. Then I used an exhaust pipe off of a semi-tractor, I then stuck the exhaust pipe into the elbow. Any metal tube that is 4-6" in diameter would work." Clever fellow with the right last name, no?
Add a chimney cap. A chimney cap like the one to the right sits on top of the chimney, keeps the rain and snow out and prevents rust. The place I bought mine doesn't sell them anymore, but maybe you can find a source.
Add a bottom grate to the firebox. My Char-Broil Silver Smoker came with a grate for cooking meat inside the firebox directly over the coals. It mounts just below the door. I use that to sizzle in sauce when I am done cooking ribs. I am told some models come with a lower grate for the charcoal to sit on, but mine didn't and I've never seen them on the Silver Smokers I've looked at in stores. The coals sit right on the bottom of the firebox with no airflow below them. So I bought a 13" x 17" grate from spare parts at Home Depot, and hack sawed it down to 13" x 15" so it would hover a few inches above the bottom of the firebox to allow air beneath the coals. Works, ahem, grate. Cost: About $10.
Make a charcoal basket. The technique is to build a charcoal basket that will hold a large pile of coals inside the firebox. With such a basket you can use the Minion Method of fire control. Invented by Jim Minion, this is a clever technique of maintaining constant temp for a long time by filling the basket part way with unlit coals and then you pour hot coals on top. The hot coals slowly ignite the coals below them and the temperature remains remarkably steady for long periods of time.
Here's how to make a charcoal basket: (a) Go to your local body shop and ask them to fabricate a square box about 12" wide x 12" long x 6" deep from flattened expanded carbon steel sheets with a 3/4 inch diamond (or whatever they had on hand). Make sure these dimensions will fit in your firebox first. They can cut a 4' x 6" length from a 4' x 8' sheet, fold it to 12" x 12" x 6", and spot weld the edges together. There is no need for a bottom if you have added a lower grate to the firebox as described above. (b) Purchase the the expanded metal and bend it yourself. Then stitch the corners together with wire or wire coat hangars. That's what Paul Salverda did in the picture above.
Add a water pan to the firebox. I like putting humidity into the cooking chamber to help keep the meat from drying out. There is some evidence that moisture and combustion gases combine to improve the flavor. So after the cooking chamber is up to heat and stabilized, I put a disposable aluminum pan filled with water on the cooking grate in the firebox directly above the coal basket. Cost: About $1.
Increase the capacity. The capacity of my COS is about six slabs of St. Louis cut slabs laid lengthwise. For our big July 4 party, I need more capacity so I use baby backs, which are shorter, and three rib racks. This ups my capacity to 15 slabs. Cost about $75.
Plug the leaks. Use a heat-resistent food-safe putty or caulk to plug the leaks on the cooking chamber, especially around the chimney. You do not need to plug the leaks on the firebox unless they are large. I used J-B WELD, readily available at hardware stores. The website describes it as an "Adhesive, laminate, plug, filler, sealant, and electrical insulator. Like metal, J-B WELD can be formed, drilled, ground, tapped, machined, filled, sanded, and painted. It stays pliable for about 30 minutes after mixing, sets in 4-6 hours, and cures fully in 15-24 hours. It's water-proof; petroleum, chemical, and acid-resistent; resists shock, vibration, and extreme temperature fluctuations and withstands temperatures up to 500°F. J-B WELD is super strong, non-toxic, and safe to use. Before it sets, you can clean up with soap and water". You mix the contents of the two tubes, apply, and let it cure. Some of it will drip down unto the cooking chamber before it cures, so put some newspaper under the chimney to catch drips. When it has cured you can trim off the excess with a knife or sandpaper. They have several products, so be sure to get the red and black tubes rated to 500°F. You might need more than one kit.
Other products that might work, but I haven't used, are Rutland Dry Mix Mortar or Cement, Victor Exhaust System Sealer, or other muffler cements, or high temperature silicone sealants. Just steer away from anything that might melt and drip on the food.
Seal the door. The idea is to put a gasket under the smoke chamber door so it seals tighter. There is no need to seal the doors of the firebox since you need airflow into that space. This won't work on all COS models because it might require you to adjust the hinges. But if you can fit a thin gasket under the smoke chamber door, do it. Rutland Gasket Kits and Gore-Tex Gasket Tape are good options. There are several options so pay attention to thickness and max temp.
Another option is Rutland High Temp Silicone Sealant or use a high temp auto silicone that is rated for 500°F or more. You can make a really thin bead around the door rim or the smoker body where the door contacts it. Lay a thin strip of kitchen wax paper or kitchen parchment paper (which is actually silicon impregnated) on top of the bead. Gently close the doors until the goo spreads out and the paper makes contact with the opposite surface all around. Lift the door and let it set. Peel off the paper. The sealant can be trimmed with a knife. Rutland Products are in hardware stores, furnace and wood stove stores, and online.
Get a good cover. Keep rain, snow, wasps, birds, and other vermin out. Cheapo covers last only a year or two. A good cover costs about $60.
Steve Friend of Weatherford, TX, says "I have used a COS for several years with low maintenance and no rust on the exterior. It sits outside 365 days a year. Everytime I use it, after the cooking is done and while the cooker still warm, I get a cheap can of cooking spray (PAM) and spray the entire cooker from top to bottom. This kind of seasons the metal much like a cast iron skillet. So far so good, no rust and a shiny patina that makes it look new."
Add a Stoker or a Guru. Rock's Stoker and the BBQ Guru are computerized thermostats connected to a blower and damper that manage the oxygen supply to your charcoal or wood fire, allowing you better temperature control. The computer can be set so the blower will be turned up high to get your coals started quickly, then it can be turned down for low and slow, then it can be turned down lower to hold the meat at your desired finished temp, and finally it can be turned off to kill the coals. You can set it so alarms ring when certain temps are reached or after an elapsed time period. You can even hook it up to a wireless router and control it from a web browser.
Insulate. Cheapo smokers are made of thin metal. That means the heat escapes quickly. If you put bricks in the bottom and cover them with foil, the cooking chamber will take more time to heat up, but it will hold heat longer and distribute it more evenly. This will also help dampen temperature spikes. You can also cut down on the heat loss by draping the cooking chamber (not the firebox) with a welding blanket or a foil insulation blanket.
Make cleanup easier. Some COS come with a small hole and a grease cup. It overflows quickly and only works if the smoker is tilted towards the grease cup. One easy solution is to line the bottom with foil. Another clever solution, add a ball valve as Paul Salverda did. Here's what he recommends: "Scrub the inside of the smoker with cleaner and a wadded up piece of foil. Put a bucket underneath the valve. Pour hot water into smoker, open valve. Repeat rinse. Wipe up the remainder. Admire your handiwork. Cook something!"
Make an ash scoop. Get a plastic half-gallon milk jug and cut it up like the one shown here. It makes a great scoop for removing cold ashes. Needless to say, do not remove hot ashes, and remember, ashes should always go into a metal can. Embers can glow far longer than you think.
Make a drain. Paul Salverda says "The next mod I'm going to do is to add a drain to make cleanup easier. I will use a hole saw to drill a 1" hole and then use a 1/2" black pipe nipple, a 1/2" ball valve and 1/2" conduit nuts to install it."
Practice. Practice. Practice. Cook one slab at a time until you have mastered the cooker and don't invite company over until then. You should get it under control in one or two more tries.
This page was revised 6/7/2010
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