Overview

How to run a clean, efficient coal bed on a Texas‑style offset so your pit stays steady, your wood lasts, and your food tastes like smoke—not soot.

Ingredients

• 1 bone‑in pork butt (8–10 lb / 3.6–4.5 kg)
• Kosher salt, 2 tbsp (18 g)
• Coarse black pepper, 2 tbsp (12 g)
• Paprika (optional), 1 tbsp (7 g)
• Garlic powder (optional), 1 tsp (3 g)
• Yellow mustard or oil for binder (optional), 2 tbsp (30 g)

Equipment

• Texas‑style offset smoker (stickburner) with clean grates
• Charcoal chimney starter
• Hardwood splits (2×3×12–16 in / 5×7.5×30–40 cm)
• Long fire poker or small garden hoe for raking coals
• Heavy welding gloves and eye protection
• Instant‑read thermometer (e.g., Thermapen) and leave‑in probe
• Infrared thermometer for grate and firebox checks
• Firewood moisture meter (12–20% target)
• Ash shovel and metal ash bucket with lid
• Hatchet or splitting axe and wedge
• Windbreak or welding blanket (for severe wind/cold)

Wood

Seasoned post oak (12–20% moisture content)

Time & Temp

Time & Temp
Smoke temp: 275 °F (135 °C)
Target internal: 203 °F (95 °C)
Approx duration: 10 hours

Assumptions and Goal

This article assumes a Texas‑style offset (stickburner) with the stack fully open, clean post oak splits, and a cook running 250–300°F (121–149°C). The goal is a lively coal bed feeding small clean flames, steady pit temps, and minimal white smoke. You’ll learn how to size and time splits, set air, and stretch your wood without starving the fire.

Why the Coal Bed Matters

The coal bed is the engine. Embers provide constant radiant heat and reliable ignition for your next split. A deep, even bed burns new wood cleanly; a weak bed forces smoldering, billowy smoke, and big temp swings. Think of splits as fuel for the flames and the coal bed as your battery—charge it early, then maintain it with measured additions.

Start Right: Building a Stable Bed

Light a full chimney of briquettes (about 80–100, 1.5–2.0 kg) until ashed over, then dump onto the fire grate, spread an even layer 1–2 in (2.5–5 cm) deep. Add two small preheated splits (roughly 2×2×12 in / 5×5×30 cm) and run with the firebox door cracked for 5–10 minutes to establish active flame. Close the door, keep the stack wide open, and set the intake so the pit settles at your target. An all‑wood start also works: stack 3–4 small splits in a log cabin over a tumbleweed or kindling, get rolling flames, then let them burn down to embers before starting the cook. Either way, don’t load meat until you have clean “thin blue” smoke and a bright coal bed.

Split Size, Moisture, and Preheating

Use seasoned hardwood at 12–20% moisture content—check with a meter on a fresh split face. For backyard offsets, aim for splits roughly 2×3 in (5×7.5 cm) cross‑section and 12–16 in (30–40 cm) long; oversize splits burn slow and dirty, matchsticks flash and fade. Stage your next split on top of the firebox or on a warming rack to preheat—warm wood lights in seconds and smokes less. If a staged split starts to smolder, rotate or move it; you want heat, not pre‑burning.

Split Timing: When to Feed the Fire

Time by signs, not the clock. Add a split when: flames are dwindling to flickers, the coal bed turns less radiant (dull red vs bright orange), or pit temp begins to sag 15–25°F (8–14°C). In many backyard offsets at 275°F (135°C), that’s typically every 30–45 minutes with 2×3 in (5×7.5 cm) splits. Open the firebox for 10–20 seconds after you add a split to flood it with oxygen and let the ends ignite; close back up once you have established flame. If the new split doesn’t light within 60–90 seconds, your coal bed is too shallow—rake coals forward, add a half chimney of lit briquettes, or feed a smaller, drier split first.

Air Management: Draft Over Dampers

Keep the stack wide open. Control heat with fuel amount and the firebox intake, not by choking exhaust. A good fire breathes: intake modestly open (often 1/4–1/2), clean flames dancing over the coal bed, and smoke that is nearly invisible. If you must close intake hard to hold temp, your splits are too big or too frequent. If you’re wide open and can’t reach temp, your coal bed is thin, grates are clogged with ash, or the wood is too wet. Wind increases draft—aim the firebox into or parallel to wind and trim intake to compensate.

Fuel Economy: Heat Where It Counts

Small, clean fires are more efficient than big, choked ones. Preheating splits reduces smolder time. Rake coals forward where air enters so new splits ignite quickly; let the back of the box be your ember bank. Keep the firebox door closed once flames are established—leaving it open wastes BTUs. Avoid unnecessary water pans; they stabilize but consume heat. Fix air leaks with gaskets, clear ash that blocks airflow, and right‑size splits so you add fewer, cleaner pieces rather than fighting one oversized log.

Day-Of Flow: A Working Rhythm

Settle the pit 30–45 minutes before meat goes on. Run two small splits to every large one to keep the bed lively. Stage the next split to preheat; when flames wane and temp dips ~20°F (~10°C), add one preheated split, crack the door briefly, confirm clean flame, then resume closed‑door running. Every 2–3 hours, rake the bed to break up clinkers and pull fresh coals forward. If the bed gets thin late in a long cook, supplement with a half chimney of lit briquettes to rebuild without over‑smoking the meat.

Example Cook: Pork Butt on a Steady Coal Bed

For an intermediate‑length cook that teaches fire rhythm, run a bone‑in pork butt at 275°F (135°C). Expect roughly 8–12 hours to reach 195–205°F (90–96°C), but cook to feel: it’s done when a probe slides into the money muscle and blade socket with little resistance and the bone wiggles loose. Wrap in butcher paper once bark sets and color is where you want it (usually 4–6 hours in). Rest wrapped in a warm cooler or holding cabinet for 1–2 hours until the internal temp drops to 150–165°F (66–74°C) before pulling. Throughout, maintain split timing by signs; don’t let chasing 5°F distract you from clean flame and thin blue smoke.

Weather and Pit Differences

Cold, wind, and rain all steal heat. Shield the firebox, shorten split intervals slightly, and use a windbreak when gusty. Heavier pits hold heat and stretch time between splits; small, thin‑walled offsets prefer smaller, more frequent splits. Humid days may show more visible steam; trust the smell—clean smoke is sweet and light, not bitter. Altitude and dry air can quicken draft; throttle intake accordingly.

Troubleshooting: Dirty Smoke, Spikes, and Sags

White billowy smoke after adding a split means poor ignition—preheat better, open the door briefly, or add a smaller split. Bitter, sooty flavor comes from choking the fire or wet wood—open exhaust, check moisture, and right‑size splits. Temp spikes usually follow an oversized split or too much intake; close intake slightly and ride it out rather than slamming the door. Chronic low temps point to a thin coal bed—rake coals forward and rebuild with lit charcoal. If splits “bridge” and don’t contact coals, re‑seat them firmly onto the ember bed.

Safety: Fire, Smoke, and Food

Treat the firebox like a forge: wear heat‑resistant gloves and eye protection when raking or adding splits. Store ashes in a metal bucket with a tight lid; embers stay hot for 24–48 hours. Operate outdoors with clear ventilation—carbon monoxide is odorless and dangerous. For food safety, keep raw pork below 40°F (4°C) before cooking, avoid cross‑contamination, and sanitize tools and surfaces. While pork is safe at 145°F (63°C), shoulder is cooked to 195–205°F (90–96°C) for tenderness. Hold finished meat above 140°F (60°C) if not serving, chill leftovers to <40°F (4°C) within 4 hours in shallow containers, and reheat to 165°F (74°C).

Notes

• Keep the stack fully open; manage heat with fuel and intake air, not the exhaust.
• Preheat the next split on the firebox so it lights in under 60–90 seconds, minimizing white smoke.
• Typical split interval at 275°F (135°C) on backyard offsets: 30–45 minutes with 2×3 in (5×7.5 cm) splits.
• Rake coals forward every 2–3 hours to keep ignition hot and airflow clear; clear ash that blankets the grate.
• If the coal bed collapses late in the cook, rebuild with a half chimney of lit briquettes rather than over‑loading wood.
• Hold cooked pork above 140°F (60°C) if not serving; rest until 150–165°F (66–74°C) internal before pulling.
• Leftovers: cool to <40°F (4°C) within 4 hours in shallow pans; reheat to 165°F (74°C) before serving.