Offset Pit Smokers

I have a smallish pit smoker; the cook chamber is about 5’ long and the cooking grates are about 22” wide. Though I prefer not to use racks to hold ribs vertical, my smoker will easily hold enough ribs in racks to feed 25-30 people, plenty big enough for me and what I do. Offset pit smokers like mine are usually trailer-mounted cookers that have a round cylindrical cook chamber with cooking racks inside, a chimney on one end, and a fire box at the other end. Often the cooking chamber is a repurposed propane tank. You can buy similar looking, but smaller smokers at Home Depot, Lowes and other BBQ stores. You can buy larger, custom-made towable pit smokers online from big manufacturers, or you can check places like Craigslist to find the local backyard guys from whence mine came. Some monster smokers look like they’re capable of swallowing a whole steer and require an entire forest to bring it to temperature. One pit, parked not far from our place, looks like a steam locomotive, it’s that big!

There’s a world of difference between the big-box store mass-market pit smokers and the trailer-mounted variety. One of the most notable differences is cost; you get what you pay for. My smoker is heavy gage steel, all welded construction and even though small compared to most of what the competition guys use, it still weighs quite a bit. My buddy, the guy with the 20 or so Kamado style cookers, built a really nice trailer mounted pit smoker lined with firebrick for insulation, which is a good idea. Apparently, his smoker uses a fraction of the wood that my smoker needs, but he went far too wild with firebrick and his smoker ended up so heavy he actually had to buy a new heavy-duty truck just to pull it around! The mass-market pits are very light gauge sheet metal with rivets and or spot welds holding everything together. They’ll work OK but I doubt that they’ll last for more than a few years, at most.

The whole basis of low-‘n-slow pit smoking is cooking with indirect heat. Basically the cooker is a smoky, wood or charcoal-fired oven. The major drawback to most all pit smokers, is that the fire box almost always is attached on one end with the chimney positioned at the opposite end. The fire box, hanging on the end of the smoker, is positioned a little below the cook chamber. Inside, most fireboxes have a large area open to the bottom of the cook chamber. The heat from the fire is almost directly under the cooking grate at the fire box end. When the fire is going, with smoke and heat wafting from the fire box through the cook chamber and out the chimney at the other end, the cook chamber is always very much hotter at the fire box than it is at the chimney end. Temperatures at the fire box are often equivalent to conventional BBQ grilling temperatures. Such an extreme temperature gradient is a characteristic that makes low ‘n slow difficult

Uneven temperatures in the chamber make it impossible to fill your smoker with meat and expect a nice even cook a few hours later. One has to frequently shift meaty morsels from the fire box end to the chimney end and vice versa. Meaty morsels’ll burn, or at least cook way too rapidly at one other end, while they’ll cook more slowly, as they should, at the chimney end.

The AWESOME Miners Mix Offset Pit Smoker

My smoker, however, is different and very special! One may not notice at first glance, but the chimney is on the same end of the cook chamber as the firebox. How does that work? My special little cooking gem is a reverse-flow pit smoker. It started life as a conventional offset pit smoker with all heat gradient problems detailed, above. I had it modified by welding a false-bottom plate under the cooking grid. The plate seals the fire box from the cook chamber and extends all the way to the opposite end where it stops short a few inches. The heat and smoke travel under the steel plate and up into the cook chamber at the far end, then back over the meats and out the chimney just above the firebox. This design doesn’t completely eliminate the hotter area close to the firebox, but it’s only 25-50° F or so hotter at firebox end than at the other end. With some additional modifications, I could probably reduce this gradient further, but it would take a lot more work. Also, I have a 1” steel pipe mounted in the very center of the cook chamber, protruding out the very bottom of the smoker. The pipe opens at the false bottom plate where it is flush welded. This nifty innovation allows grease dripping from the meat to drain into a bucket under the smoker, or the occasional high pressure wash water to drain out of the smoker. One final modification is a small water tank I had mounted inside the top portion of the fire box. The tank is welded to a pipe that penetrates into the cook chamber, all the way to the far end where it opens. There is a pipe nipple from the tank that extends outside the firebox from which I can fill the water tank to facilitate steam being injected into the cook chamber. Ribs and other meats stay nice and moist with this system.

An interesting thing I’ve noticed with this smoker is that temperatures in the chamber are dependent on the angle of the chamber relative to the fire box. Raising or lowering the far end of the smoker with the trailer jack will actually rapidly change the chamber temperatures as much as 100° F or more, depending on the angle that the smoker is tilted up or down. Makes sense when you consider that heat rises. I strive to keep things on the level, but the ability to rapidly change temperatures just by tilting the chamber is helpful.

For cooking, I live in an area with lots and lots of almond groves, so that’s my wood of choice. I started out using oak, which is also abundant here, but the smoke flavor from oak is very heavy and overpowering. Almost all fruitwood is good for smoking; meats smoked with almond come out with a nice and light fruity smoke flavoring, even when on the smoke for 5 hours or more. There are online links with tables that describe smoking with different woods and the degree of smokiness imparted to the meats. Please be sure to use woods that are safe to smoke with. Never use pines, eucalyptus, or unknown woods as some are toxic.

My smoker, like nearly every other pit smoker ever made, has circular dial-faced thermometers mounted onto the upper portion of the chamber with sensing probes that protrude into the upper portion of the cook chamber. These thermometers do a fine job of measure the temperature of the air, way above the cooking surface. However, no one cares what the air temperature is; all the action happens down below, on the cooking grid. Temperatures, at least on my smoker, average 50° F cooler on the cooking surface than in the air only 5-6” higher. It is for this reason you need one of those digital thermometers with a probe you can mount onto the grill, next to your rack of ribs, so you know what’s going on there rather than the air temperature above.

In doing a 4-5 hour smoke, I strive to maintain the temperature at around 250° F or so at the grill, where the meat is placed. From experience, I know those dial thermometers will indicate about 300° F when my cook grid temperature is 250° F. I regulate the temperature using only the damper on the fire box. I almost never close off the chimney to control temperatures. I don’t know if this is the best way or not, but it works for me. For best results, I’ll spritz the ribs or butts every half hour or so, after the first hour in the cooker with apple or pineapple juice mixed with brown sugar. After a couple of hours, my ribs acquire a beautiful shiny, reddish brown glaze.

Next up: the remainder of my grill arsenal. I’ll even talk about the gas grill I still use!