Smoking

Part of Leatherwork

Smoke-treating leather for preservation, water resistance, and insect deterrence.

Why This Matters

Smoke treatment is one of the oldest and most effective methods for preserving leather, predating even formal tanning by thousands of years. Indigenous peoples across North America, Siberia, and Southeast Asia developed sophisticated smoking techniques that produced leather with properties modern chemistry struggles to match — soft, water-resistant, antimicrobial, and remarkably durable.

In a rebuilding scenario, smoking serves several critical purposes that other preservation methods cannot easily replicate. Smoked leather can get soaking wet and dry soft again, while most vegetable-tanned leather dries stiff and hard after wetting. This single property makes smoking invaluable for clothing, moccasins, and shelters that will see rain and river crossings. Smoke also deposits antimicrobial compounds — primarily aldehydes and phenols — that prevent bacterial and fungal growth, extending the leather’s life by years.

Smoking is also remarkably accessible. It requires no chemical knowledge, no special ingredients beyond wood and fire, and no elaborate equipment. A simple pit or frame structure, the right wood, and patience are all you need. This makes it the go-to preservation technique when tannin-rich barks aren’t available or when you need treated leather quickly.

The Science Behind Smoke Treatment

What Smoke Does to Leather

Wood smoke contains hundreds of chemical compounds. The ones most important for leather treatment are:

Compound Group	Effect on Leather
Aldehydes (formaldehyde, acrolein)	Cross-link collagen fibers, creating chemical bonds similar to tanning
Phenols (creosol, guaiacol)	Antimicrobial action, prevent rot and mold
Organic acids (acetic, formic)	Lower pH, inhibiting bacterial growth
Tars and resins	Coat fibers, providing water resistance
Soot particles	Fill pores, add color, reduce water absorption

The combined effect is a form of aldehyde tanning. The formaldehyde and other aldehydes in smoke form permanent cross-links between collagen molecules in the hide. This is the same chemical mechanism used in modern chamois leather production (which uses fish oil aldehyde tanning). The result is leather that remains soft when wet and resists decomposition.

Why Smoked Leather Dries Soft

In untreated or poorly tanned hide, when water evaporates, collagen fibers bond directly to each other as they dry, creating a rigid, board-like material. Smoke-deposited compounds occupy the spaces between fibers, physically preventing them from bonding to each other during drying. The fibers remain individually mobile, and the leather stays supple.

Wood Selection

The choice of smoking wood dramatically affects the final product:

Best Woods for Leather Smoking

• Willow — Traditional among Plains peoples. Produces abundant cool smoke with high aldehyde content. Excellent results.
• Cottonwood — Very similar to willow, widely available near waterways. Burns slowly, good smoke production.
• Alder — High phenol content, good antimicrobial properties. Produces a warm brown color.
• Birch — Distinctive aromatic smoke. Bark produces heavy, resinous smoke for waterproofing.
• Poplar — Burns cool and slow, easy to control. Good general-purpose smoking wood.

Woods to Avoid

• Pine, spruce, fir (softwoods with high resin) — Produce harsh, sooty smoke that can darken leather excessively and leave sticky resin deposits. Small amounts mixed with hardwood are acceptable, but pure conifer smoke produces inferior results.
• Cedar — While aromatic, the oils can be irritating to skin worn close to the body.
• Treated or painted wood — Obviously avoid anything with chemical treatments, paint, or adhesives.

Green vs. Dry Wood

Use partially rotted or punky (soft, decayed) wood for the best smoke. Fresh green wood produces too much heat and flame. Bone-dry wood burns too fast with too little smoke. The ideal is wood that crumbles slightly when squeezed — it smolders slowly, producing dense, cool smoke rich in the desired compounds.

Smoking Methods

Pit Smoking

The simplest and most common method:

1. Dig a pit 30-40cm deep and about 30cm in diameter.
2. Start a small fire in the pit using dry kindling. Let it burn down to coals.
3. Add smoking wood — punky wood, wood chips, or sawdust — to the coals. The wood should smolder, not flame. If flames appear, sprinkle water or cover partially with a flat stone.
4. Create a frame by sticking flexible branches into the ground around the pit, bending them inward to form a dome.
5. Drape the hide over the frame, flesh side facing the smoke, creating a tent that traps smoke around the leather.
6. Seal the base with dirt, stones, or cloth to contain the smoke. Leave a small gap at the top for airflow — smoke must flow through, not just stagnate.
7. Maintain the smolder for 4-8 hours, adding wood as needed. The leather should turn a golden to dark brown color throughout its thickness.
8. Flip the hide and smoke the grain side for an additional 2-4 hours.

Tipi/Cone Method

Used historically by Plains peoples, this method uses a conical frame:

1. Set three or four poles in the ground, leaning together at the top to form a cone about 1.5m tall.
2. Sew or pin the hide into a cone shape that fits over the frame.
3. Build a small smolder fire at the base inside the cone.
4. The cone shape creates a natural chimney effect, drawing smoke upward across the leather.
5. The top is partially closed to slow airflow and maximize smoke contact time.

This method is particularly effective because the rising smoke contacts both sides of the leather as it flows between the hide and the pole frame.

Smoke Bag Method

For smaller pieces or already-assembled items:

1. Sew the leather piece into a bag shape with the flesh side outward.
2. Attach the open end over a smoke source — a smoldering pot, a hole in the ground over coals, or the end of a smoke tube.
3. The smoke fills the bag, contacting the flesh side from inside.
4. After 3-4 hours, turn the bag inside out and repeat for the grain side.

Process Control

Temperature

Keep smoke temperature below 60°C (140°F) at the leather surface. Excessive heat will cook the collagen, making the leather brittle and destroying the very fibers you’re trying to preserve. If you can hold your hand at the leather’s distance from the smoke source without discomfort, the temperature is appropriate.

Duration

Smoking time depends on leather thickness and desired intensity:

Leather Thickness	Minimum Smoking Time	Recommended Time
Thin (brain-tanned deer)	3-4 hours	6-8 hours
Medium (goat, sheep)	4-6 hours	8-12 hours
Heavy (cattle)	8-12 hours	16-24 hours (in sessions)

The leather is done when the smoke color has penetrated completely through the thickness. Cut a small test strip from the edge — the color should be uniform from grain to flesh side.

Color Results

• Light smoking (2-3 hours): Pale gold, mild preservation
• Medium smoking (4-8 hours): Warm brown, good water resistance
• Heavy smoking (12+ hours): Dark brown to near-black, maximum preservation and waterproofing

Combining Smoking with Other Methods

Smoking works excellently as a finishing step after other tanning methods:

• Brain tan + smoke: The classic combination. Brain tanning makes the leather soft; smoking locks in that softness permanently and adds water resistance. This produces the finest buckskin.
• Bark tan + smoke: Adds water resistance and antimicrobial protection to vegetable-tanned leather. Also makes bark-tanned leather dry softer after wetting.
• Oil tan + smoke: Smoke treatment after oil tanning creates extremely water-resistant leather suitable for marine applications.

Re-Smoking

Leather can be re-smoked periodically to refresh its water resistance and antimicrobial properties. After heavy use or extended exposure to rain, a 2-3 hour re-smoking session restores much of the original protection. This is especially useful for moccasins and clothing.

Safety Considerations

• Never smoke leather in an enclosed space where you’ll be breathing the same smoke. Work outdoors or in well-ventilated areas.
• Keep water nearby to control flare-ups. A smolder fire that ignites can burn the leather before you react.
• Monitor the fire constantly during the first hour until the smolder stabilizes.
• Avoid inhaling smoke directly — the same aldehydes that preserve leather are respiratory irritants.