If you can’t take the heat, use cold smoke. Learn how to construct a homemade cold smoker box to flavor all your food without having to time it perfectly.
Years ago, I read a description in a text, the name of which has long since been lost in my memory, of a cold smoker built into the hills of Appalachia. I’d never heard of such a thing. It had a small firebox in the ground that poured smoke into a horizontal chimney, also in the earth. From there, the smoke, now much colder (having bled a great deal of its heat into the soil), filled a small shack with its flavor-enhancing mist through a hole in the floor. It became one of those projects I just couldn’t let go.
Flavoring food with smoke, without having to time it perfectly, is a fantastic idea. While an apparatus of that size and scope is a decent undertaking, there are upsides of having it in your yard. Sometimes, friends come back from Alaska with more salmon than they can preserve. Sometimes, you wonder if the deer you took to the locker plant is the deer you got back, and what if you had cold-smoked it first so you could tell for sure? What if you cold-smoked your Thanksgiving turkey and then deep-fried it? What if there’s enough room to do a turkey, pork belly, and a tray of table salt at the same time? How do smoked artichokes taste?
Homemade Cold Smoker Box Construction Tips
Firepit. A brick-lined hole for your fire pit will offer options for size and configuration but gets a little messy where the smoke tube exits the pit. An upcycled 55-gallon steel drum will keep the dirt out but may still need a protective brick liner to keep it from turning into a rusty crumble. In a convenient coincidence, the lid of a large charcoal grill is close enough to the size of a steel drum to make an attractive, dampenable top. If the site grade allows, a side-loading door can help you add fuel and allow in just enough oxygen to keep it smoking.
Door. When I was about 6, my older brother and his friend got the business from the friend’s mom for locking me in a chicken coop. This was back when the friend’s mom could swat her son and my complicit brother with a slotted spoon. While it isn’t fun to be held hostage in a dirty chicken coop for hours by your brother and his goon, it isn’t deadly like being locked in a smokehouse would be. Make sure the door can open from the inside. A spring-return to keep the door closed is much safer than a latch that hooks from the outside; on the reverse, a wedge or pole to hold the door open while you’re inside the smoker can keep it from becoming deadly.
Space and Sizing. Looking back on the inside of that dirty chicken coop (during my incarceration, I had plenty of time to capture a mental picture of it and ponder the decisions of my short life), I now envy its relative roominess and wish I would’ve built my smoke shed a bit closer to its dimensions instead of the 3-by-3-by-4-foot structure that it is. I intended it to be big enough to fit a whole hog or a deer. The existing space is optimized; wires hold stainless-steel hooks to hang cuts, and the bottom has kitchen-grade wire shelves that make great smoker furniture, both for hanging hooks and for holding pre-loaded trays. Even then, the shed feels small when loading and unloading it. Also, having space doesn’t mean it’s usable. Getting something from the back hook isn’t easy when something hangs in front of it, and crouching down to do it isn’t fun.
Lumber. Non-treated dimensional lumber is the cleanest construction option. If plywood or oriented strand board (OSB) is what you’ve got or can afford, at least get the glue off.
Smoke Tube. If you use a smoke tube between the fire pit and the shed, a stainless-steel stovepipe is the most durable. It’ll rust out eventually, but it’ll last a long time, and you can pour concrete around it to hedge against that. You may be tempted to use galvanized ducting to delay corrosion, but the zinc plating’s melting point and your fire’s temperature would overlap to bestow an awful metallic taste and give the gift of zinc poisoning. A leftover double- or triple-insulated stainless-steel stovepipe offers an appealing off-the-shelf solution. Just be aware that, eventually, the dirt will rust the carbon steel outer layers, which you don’t want on it anyway, because they’ll keep the ground from absorbing the smoke’s heat; this is the point of burying the tunnel. If you’ve got the time and energy, a brick or cinder block tunnel from your fire pit to your shed will probably serve you best, but you’ll need to keep dirt from caving into the cracks – either mortar them or stagger extra bricks or other barriers on the top and sides. The smoke tube should be at the highest point possible in the fire pit to give the smoke a convenient exit, and the tube should be no less than 4 feet long to let the ground do its work.
Pest Prevention. While the vision of a shed pouring out smoke from all the cracks in its seams is a romantic one, this building is going to smell like food. The smoke will drive critters out when you’re using it, but it can’t drive out the hantavirus, so build construction tight enough to keep out unwanted guests.
Stainless-steel mesh on the ends will minimize the smoke tube’s appeal as a rodent hotel. The mesh needs to go on the shed side and the fire pit side. If you can make a tight-fitting lid, the fire-side mesh may be a moot point, but if your fire pit is a collection of bricks lining a hole in the dirt, you may enjoy the extra security.
Keep the Smoke Moving. By the time the smoke is in your smokehouse, it’ll have lost a lot of heat. This is great for your food as long as the smoke keeps flowing in, and for that to happen, it needs to keep flowing out. Normally, the heat takes smoke up and out of a chimney. Because of the low temperature, it’s more sensitive to things that might cause minor atmospheric pressure differences, such as grade and wind direction. To lessen these obstacles, put your smokehouse downwind of your fire pit, and construct some uphill grade between your fire pit and smokehouse. No grade, no flow. Once the smoke is in the smokehouse, it needs to get out through the top, and a chimney will give momentum in the right direction. A directional chimney cap will use the breeze to help suck out the smoke while protecting against rain. If all else fails, cheat by pulling the smoke in or out with a low-amp CPU fan from a junked-out computer; it can run for a long time on batteries and holds up well against the noxious cargo it’s moving.
Words of Caution
I love the flavor of smoked food. I also like the versatility cold-smoking offers; you can smoke something for as long or as short as you’d like – the actual cooking happens by another means. Unless you don’t intend to cook it – the low temperature lends itself well to delicate foods, such as cheese, and what jerky recipe wouldn’t benefit from some authentic smoke flavor? With this convenience, and because more is always better, comes the temptation to add a lot of smoke flavor to your food. It’s much easier to put in than to take out, so consider adding precooked control samples to your load so you can reward yourself with a taste test along the way and save yourself the disappointment of over-smoked food.
Speaking of disappointments, long after the chicken coop incident, another situation blessed me with the opportunity to evaluate my life choices. I was having a barbecue with family and friends who inevitably gathered around a cooler while I went to the other side of the house to check the smoker. It was drafting well because of the light breeze, which also muffled my cries for help when it blew embers onto the nearby dry sagebrush and turned them into man-tall flames. I wondered if Moses panicked less when he encountered similar circumstances. If I’d corralled my smoking activity to the cool season, this never would’ve happened. If I’d surrounded the fire pit with pavers, it would’ve made the area safer, and I could’ve used them as tablets to carve commandments on, in case this wasn’t just a dress rehearsal. At the very least, I should’ve done a better cleanup around the fire pit, which might’ve made a nice marshmallow and hot dog roasting spot if it had pavers around it.
From the Kitchen to the Smokehouse and Back
Trays make it much easier to transfer foods from the kitchen to the smokehouse. Pizza stones are a great nonmetallic way to get this done, but if you don’t make a little dam out of paper towels to catch the drip, they can get messy.
Further Reading
In my quest to find the original inspiration for this build, I ran across some worthy articles about the subject. Both A.D. Livingston’s Cold-Smoking & Salt-Curing Meat, Fish, & Game and Marian Faux’s Drying Curing & Smoking Foods are rife with recipes and provide great illustrations of in-ground smokers.
Josh Lau is an engineer, inventor, and Eagle Scout. He raises chickens and steers on a small ranch in central Oregon with his patient wife and awesome kids.