# Pit Firing Pottery: What You Need and What Can Go Wrong

Cluster: Firing & Kilns
URL: https://claybook.studio/blog/pit-firing-pottery-at-home/

# Pit Firing Pottery: What You Need and What Can Go Wrong

Pit firing is the oldest way to fire pottery. You bury or surround your pots with fuel, light it and let it burn. The flames, smoke and ash leave marbled blacks, oranges and grays that no glaze can copy.

It is also unpredictable and carries real safety concerns. This guide explains what happens and how to approach it responsibly.

## How pit and barrel firing work

In a **pit firing**, pots sit in a hole in the ground or a shallow pit, surrounded by wood, sawdust and other combustibles. In a **barrel firing**, the same idea happens in a metal barrel, which gives you a bit more control and protection from wind.

Temperatures are lower and less even than in a kiln, often reaching somewhere in the low-fire range. See the [cone chart](/blog/pottery-cone-chart/) for comparison. Pots end up porous and unvitrified, so the surfaces are decorative, not durable or watertight.

## What makes the colors

* **Carbon** from smoke settles on the clay and creates black and gray.
* **Combustibles** such as sawdust, seaweed, dried leaves or other organic material create patterns where they touch the pot.
* **Burnishing** (polishing with a smooth stone or the back of a spoon) gives a gentle sheen that holds the smoke marks.
* **Metal salts** wrapped near the pot can add colors, though they require care and research.

Because oxygen and fire move unpredictably, no two pots look the same. Read more about [pit firing](/learn/pit-firing-the-oldest-kiln-in-the-world/) and [burnishing](/learn/burnishing-a-special-technique/).

## Preparing your pots

* **Make well-built pots** with even walls and no trapped air. Thick joins and uneven walls often crack.
* **Use a clay body** suited to thermal shock. A coarse body with grog usually does better.
* **Dry completely.** Moisture causes pots to burst.
* **Burnish** the surface at leather hard for a smooth finish.
* **Bisque fire first**, if you can. It makes the pot stronger before the pit.

See [prepare pots for a pit or barrel firing](/practice/prepare-pots-for-a-pit-or-barrel-firing/).

## The basic process

1. Dig or set up the pit or barrel in a safe, open place.
2. Add a bed of sawdust or similar material.
3. Place pots gently and surround them with combustibles.
4. Build wood on top and light it.
5. Burn for hours, then let it cool completely, often overnight.
6. Remove pots carefully, brush off ash and clean the surface.

The exact materials and layers vary a lot. Follow instructions from an experienced instructor rather than improvising.

## Safety is not optional

* **Check local rules.** Open fires may be banned during dry or windy periods, and many places require a permit.
* **Choose a safe spot** away from buildings, trees and dry grass.
* **Never fire in strong wind.**
* **Keep water, a shovel and a fire extinguisher nearby.**
* **Wear cotton or wool clothing**, closed shoes and heat-resistant gloves.
* **Don't leave a fire unattended.**
* **Smoke is harmful.** Stay upwind and avoid breathing it. Some combustibles and additives release toxic fumes, so do your research.
* **Cool pots are still hot.** Test with a gloved hand.

If you are new, take a workshop or join a group firing.

## What can go wrong

* **Cracked or shattered pots.** The most common outcome of too much moisture or thermal shock.
* **Pale or washed-out results.** Not enough carbon or heat.
* **Soft, chalky pots.** They are porous, so don't use them for food or liquid.

Treat pit-fired work as sculpture and decoration. For food-safe vessels, see [is my pottery food safe](/blog/is-my-pottery-food-safe/).

## Keep notes

Because every firing is a one-off, write down the pit setup, the combustibles and the weather. Photograph the pots before and after. Even if you can't repeat the result exactly, you will improve the odds.