Atmospheric firing
Wood-fired pottery, where the fire does the decorating
A wood kiln is not a hotter version of the kiln you already know. It is a machine for pushing flame and ash across your pots for days at a time, and the marks it leaves are the finish. Nobody brushes those on. Here is how the process works, what you make differently for it, and what you need to have sorted before somebody trusts you with a spot in their kiln.
Written for the member who picked up a wood-fired cup somewhere and could not work out how the color got there, and for the member about to help load an anagama for the first time.
The short version
Wood firing in eight sentences
Everything on this page rests on these eight. If you only read one band, read this one.
The kiln is doing the decorating.
Wood ash lands on the pots, melts at high temperature, and becomes glass on whatever surface it settled on. You are not painting a finish. You are aiming one.
Where a pot sits decides how it looks.
The flame takes one path through the chamber. A pot in the front near the firebox gets buried in ash. The same pot at the back comes out quiet and dry. Both are correct.
Your clay body matters more than any glaze.
Iron and other impurities in the clay react with the flame and give you the color. A refined white clay in a wood kiln mostly stays a refined white clay.
Everything gets stuck to everything.
Melting ash welds a pot to the shelf. So every piece stands on small wads of refractory clay, and every lid is wadded in its own seat.
One side of a pot is not the other side.
Wood firers talk about the flame face and the shadow side. Make forms that are worth looking at from both, because you do not get to choose which one faces the fire.
A firing is days, not hours, and it is a team.
Somebody is stoking every few minutes for the whole run, in shifts, overnight. Turning up for the shifts is how you earn a spot in the next one.
Line the insides of anything you will drink from.
Ash deposit is uneven and can be rough or pinholed. A tested liner glaze inside a cup is the one piece of glazing nearly everybody still does.
You will not get every pot back.
Some come out welded down, cracked, or simply dull. Everyone who fires these kilns accepts that, and it is the reason you send test tiles the first time.
Six minutes on what wood firing is and why anybody still does it, from a community studio that runs a kiln. Watch on YouTube
What you actually hand over on loading day
- Pots in a clay body the kiln owner has approved. Ask before you make anything.
- Bone dry work, bisque fired if that is what they have asked for.
- A liner glaze inside anything meant for food or drink.
- Wadding made to their recipe, and more of it than you think you need.
- Test tiles. Two or three clays, two or three slips, so one firing teaches you something.
- Your name on the bottom of every pot, and your hours on the stoking roster.
Start here
What is actually happening in there
Half an hour on one complete firing, from making the pots to opening the kiln. If you watch one long video on this page, make it this one. Watch on YouTube
Burn a log and most of it leaves as gas. What stays behind is ash, and ash is mostly silica, calcium, potassium and a little phosphorus. Those are glaze materials. They are, in fact, roughly the ingredients of a simple high-fire glaze, which is not a coincidence and is the whole reason this technique exists.
At kitchen-fire temperatures ash is just dust. Get it above about 2,200 degrees Fahrenheit, which is where a wood kiln lives, and it starts to melt. Now you have a kiln full of hot moving air carrying molten glass in suspension, and it is landing on your pots.
Two things happen at once. Ash builds up physically on horizontal surfaces and on the side facing the firebox, and where it is thick enough it runs, pools in the shoulders of a jar, and drips. That is the glassy green-gold surface people recognize. And the atmosphere reduces , because a wood fire chokes itself on its own smoke, and a kiln starved of oxygen starts pulling oxygen out of the clay and glaze instead. Iron changes color. Whites turn to warm grays. Flashing slips go orange.
So a wood-fired pot carries a record of where it stood and what happened to it. That is a genuinely different proposition from an electric firing, where the point is that every pot on every shelf comes out the same.
Both approaches are honest. We fire electric here, to cone 5½, and we do it because repeatability is exactly what 300 people sharing a kiln need. Wood firing is the opposite trade: you give up control and you get something nobody can reproduce, including you.
Why this page has both
Read it first, then watch somebody do it
Lists on one side, potters on the other
Every section here hands you the words first and the video second. Read the list, watch the hands, then go and do the thing.
Video is the only honest way to show you some of this. No paragraph is going to tell you what it sounds like when a firebox takes a fresh armful of split pine, or how fast the flame answers, or what a kiln looks like at 2,300 degrees when somebody pulls the spy plug. You have to see it.
But video runs at the teacher's pace instead of yours. When the number you needed goes past at minute eleven, you are scrubbing a timeline with a wet thumb, hunting for the sentence again. Video is also poor at holding still. A ratio, a cone number, a wadding recipe: they all slide off the screen while you are still thinking about the last one.
Text does the opposite job. You set the speed, your eye jumps back up a list without losing its place, and a number sits there long enough to write down.
What we keep finding is that the order matters more than the medium does. Read first and you build a frame. Then the video drops into a frame that already exists, and you start noticing what the potter is choosing rather than just enjoying the fire. Watch first and it is a lovely video that leaves very little behind.
So that is how this page is built. Short blunt lists, then somebody doing it, section after section. The lists are short on purpose, because they are meant to be read off a phone propped against a bucket by somebody with clay on their hands.
If you only have a few minutes, hit Nutshell at the top. Same teaching, a fraction of the words, and it remembers your choice on every other page on this site.
Know which one you are standing in front of
Five wood kilns you will actually meet
People say wood kiln as though it were one object. It is a family, and the differences are not trivia. The shape of the kiln decides how long you fire, how much ash lands, and how much say you get in what your pots look like.
Anagama
One long tunnel running uphill, firebox at the bottom, chimney at the top. Everything the fire touches on its way through gets ash. Fires for days. The heaviest deposits and the biggest differences from front to back of any kiln here.
Noborigama
The anagama split into a staircase of separate chambers, each one stoked in turn through its own ports. Later chambers ride on the heat of the earlier ones, so it is far more efficient, and each chamber can be loaded for a different result.
Train kiln
A long low crossdraft chamber with the firebox at one end and the stack at the other. Popular in American studios because it fires in roughly a day and a half rather than a week, and it still gives real ash on the firebox end.
Bourry box
Wood is laid across bars above the combustion chamber and burns from underneath, so it needs stoking every fifteen or twenty minutes instead of every three. Kinder on a small crew, cleaner burning, less dramatic ash.
Fast-fire
Small, lightly built kilns designed to reach temperature in eight to sixteen hours. Common at schools and workshops because a class can load, fire and unload inside a weekend. Less ash, but the real thing in every other respect.
And the odd ones
Groundhog kilns in the American South, onggi kilns in Korea, manabigama and other small hybrids. If somebody offers you a spot in one, take it. The rules on this page still apply.
A thorough classroom walk through wood kiln design and why each shape exists. Dry, and worth it. Watch on YouTube
A weekend workshop on a train kiln, which is the kind of firing most people get invited to first. Watch on YouTube
The one question to ask before you make anything
Ask the kiln owner how long the firing runs and where in the kiln your work is likely to sit. A three-day anagama near the firebox and a sixteen-hour fast-fire at the back are two different briefs, and they want two different pots from you.
The four marks
What the fire actually leaves behind
Seventeen minutes on atmospheric firing in general, which is the family wood, salt and soda all belong to. Watch on YouTube
Almost everything you will see on a wood-fired pot is one of four things, and being able to name them is the difference between admiring a pot and reading one.
-
Ash deposit
Ash lands, melts and becomes glass. Thin, it is a dry blush. Thick, it is glossy and green or amber and it runs downhill, pooling above a foot or in the shoulder of a jar. Heaviest on the flame face and on any upward-facing surface.
-
Flashing
Color from the flame itself passing over bare clay, without enough ash to make glass. Oranges, pinks and warm grays, strongest on clays and slips that hold a bit of iron or a lot of alumina. This is the effect most people are chasing and it is easy to smother with too much ash.
-
Reduction color
A wood fire starves itself of oxygen every time you stoke, so the kiln pulls oxygen back out of the iron in your clay. Iron that would be honey brown in an electric kiln goes gray, green or black instead. Same clay, different fire.
-
Carbon trapping and shadows
Where a pot touches another pot, a shelf, or a wad, the flame cannot get in. You get a hard-edged pale shadow, sometimes with carbon caught under the surface as a smoky gray. Potters stack pots deliberately to draw these.
The flame face is not a metaphor
Pick a wood-fired pot up and turn it. One side will be darker, glassier and busier than the other. That is the side that faced the firebox. When you load, you are choosing which face of your pot gets that, and it is the single most consequential decision anybody makes on loading day.
The decision that outranks every other one
Your clay body is doing most of the work
Two pots in different clays, sitting side by side on the same shelf in the same firing, come out looking like they were made on different continents. Before you throw anything, find out what the kiln owner wants you in, and why.
| What it does in a wood kiln | Worth knowing | |
|---|---|---|
| Iron-bearing stoneware | The workhorse. Iron reduces to warm grays and toasty browns, and ash sits on it beautifully | If somebody says just bring a dark stoneware, this is what they mean |
| Grogged or sandy bodies | Rough tooth catches flashing and holds thick ash without crawling. Survives long soaks and thermal stress | Nearly every dedicated wood-firing body has grog in it. There is a reason |
| Porcelain | Ash reads as clear glass over white, and flashing goes soft pink and orange. Spectacular when it works | Warps and slumps at cone 11 and up. Ask before you commit a kiln load to it |
| Refined white stoneware | The quiet one. Little iron means little reaction, so it mostly comes out looking like itself | A flashing slip is what rescues this. Bare, it is often the dullest thing in the kiln |
| Wild and local clay | Unpredictable and often the best surface in the firing. Wild clays are usually full of the exact impurities that react | Test it hard first. Some wild clays are nowhere near cone 10 and will puddle |
| Anything low-fire | Melts. Completely. Takes the shelf and whatever is next to it with it | This is the one genuine disaster on the list. Check your cone range, twice |
Send test tiles the first time. Every time, really.
Two or three clays and two or three slips, all clearly marked on the back, spread across different spots in the kiln. One firing then teaches you something you can use for the next ten years. Going in with a single clay and no tiles teaches you almost nothing about why the pots look the way they do.
Mark the bottom before it is dry
A wood kiln unloading is fifteen people picking through several hundred pots that all just got the same treatment. Your maker's mark is how yours comes home with you. Stamp or carve it while the clay is leather hard, and make it deeper than feels necessary, because ash fills a shallow one right in.
Marc Lancet on whether to glaze at all, which is really a talk about letting the clay body do the work. Watch on YouTube
At the wheel and the table
Making pots that are worth the fire
You are making for a process that will attack the pot from one side for three days and then run molten glass down it. That changes a few of your normal habits. None of it is difficult, but all of it is easier to do at the wheel than to fix later.
- Give it a shoulder, a lip, a ridge, something. Ash needs a horizontal surface to catch on and an edge to run over. A smooth straight cylinder gives the fire nothing to grab, and that is exactly how a pot comes out looking like it was in the wrong kiln.
- Make both sides worth looking at. You do not choose which face meets the flame, so a design that only works from one angle is a coin flip.
- Raise the foot slightly and keep it clean. Wadding goes under it, ash runs down toward it, and a pot with a crisp undercut foot is far easier to grind free afterward than one that meets the shelf at a soft angle.
- Do not throw it thin. A long firing and a slow cool are hard on a pot, and thin walls plus heavy ash on one side is how things crack. A little more weight than you would leave for a cone 5½ electric firing is the right instinct.
- Round over every rim, handle join and lid edge. Sharp edges collect ash first and end up razor sharp in glass, and they are the first thing to chip in the kiln.
- Lids get fired in place, so make the gallery generous. They are wadded, and wadding takes up room. A tight fit before firing is a fused lid afterward.
- Think about how it stacks. Pots that nest, sit on each other, or lean deliberately give you carbon shadows for free, and kiln space is the scarcest thing in the building on loading day.
- Dry it properly and dry it slowly. A wet pot in a wood kiln is somebody else's disaster as well as yours. Our drying guide applies here with the volume turned up.
- Make more than you need. Some will not come back. Everybody who fires these kilns builds that into the plan.
Bisque or raw?
Most wood kilns want bisque fired work, because a long firing full of raw pots means a very slow start and a lot of risk from anything still holding water. Some potters raw fire on purpose and get a particular quality out of it. This is not your call to make. Ask, and do whatever they say.
The unglamorous part that saves your pots
Wadding, and why nothing sits flat
Molten ash does not care what it lands on. It will happily glue your bowl to the shelf, your lid to its gallery, and one pot to its neighbor. Wadding is the small lump of stubborn clay that refuses to melt and keeps those things apart.
Florian Gadsby making wadding from scratch and using it, with the clearest explanation of why the recipe is what it is. Watch on YouTube
Marc Lancet on wadding materials and methods specifically for wood firing, including the trade-offs between mixes. Watch on YouTube
-
Use their recipe, not one you found
Every kiln has a house wadding mix. A common starting point is equal parts alumina hydrate and kaolin or fireclay, sometimes with sawdust or rice hulls worked in so it crumbles off cleanly. Ask, then make theirs.
-
Mix it stiff and roll it out
You want it firm enough to hold a shape under the weight of a loaded pot but soft enough to squash flat when you press the pot down. Roll a rope, cut pieces, and keep them under plastic so they do not dry out before loading day.
-
Three wads under everything
Three points define a plane, so three wads sit stable on a shelf that is never quite flat. Four is a wobble. Keep them small, roughly the size of a pea for a cup and a marble for a jar, and set them in from the edge of the foot so the mark is less visible.
-
Wad every lid, in its own seat
Three tiny wads in the gallery. The lid is going to fuse otherwise, and a fused lid is a broken pot rather than a repairable one. Same for anything with a stopper, a spout resting on a shelf, or two pots stacked rim to rim.
-
Press the pot on and give it a small twist
You want the wad flattened and gripping, not perched. If a pot rocks on its wads on the bench, it will rock in the kiln, and a rocking pot in a three-day firing usually ends up leaning against its neighbor.
-
Plan to grind the scars
Wads leave three rough spots. That is a normal part of a wood-fired foot and everybody grinds them, with a diamond pad or a bench grinder, then runs a finger around the edge to check for anything that would scratch a table.
Bring twice as much as you think
Running out of wadding halfway through loading is the classic first-timer moment, and it stops the whole crew. It costs almost nothing to make and it keeps in a bag for months.
Slips, liners and the restraint to stop
What you put on before it goes in
The instinct from an electric studio is to cover the pot. Fight it. A wood kiln rewards bare clay and punishes a thick glossy glaze, which just sits there absorbing everything the fire was trying to give you. What most wood firers actually apply is thin, partial, and chosen to react.
Flashing slips
A thin white or pale slip, high in alumina, brushed or dipped on leather hard or bisque work. It does not melt. It reacts with the flame and the sodium and potassium in the ash and turns orange, pink and gray where the fire hits it. This is the single most useful thing to apply, and it is the reason wood-fired pots often have those warm blushes on an otherwise dark clay.
Liner glazes
Inside anything you will eat or drink from. Ash deposit is uneven, sometimes pinholed, and not something you want to scrub coffee out of. A tested cone 10 liner, usually a shino, celadon or plain white, brushed or poured in and wiped back below the rim.
Shino and other reactive glazes
Shinos, ash glazes and iron glazes all do things in a wood kiln they will never do in an electric one. Carbon trapping in a shino is a wood and gas firing effect. If you want a glaze on the outside, use one that has something to say to the flame.
Leave some of it bare
Glaze one side, or the top third, or nothing at all. The contrast between a glazed area and raw flashed clay is most of what makes these pots interesting, and it is very easy to lose by covering everything.
Two minutes of a flashing slip going onto pots for a wood firing, which is all the demonstration this really needs. Watch on YouTube
Simon Levin on one specific trick for getting a much better wood-fired surface. Two and a half minutes, high payoff. Watch on YouTube
Nothing glazed goes near the shelf
Keep glaze at least a finger's width up from the foot, further than you would for an electric firing, because ash lands on top of your glaze and makes it run further than it was ever formulated to. A pot glued to a kiln shelf is a bad afternoon for whoever owns the shelf.
Loading day
You are choosing an address, not finding a gap
A full wood kiln load, start to finish, at real speed. Watch how much time goes into deciding where each pot stands. Watch on YouTube
In an electric kiln, loading is packing. You are fitting the most work into the space without anything touching. In a wood kiln, loading is composition, and it takes a whole day because every pot you set changes what happens to the pots behind it.
-
The flame has one path, and you can see it
It comes off the firebox, up over the bag wall, through the ware, and down or along to the flue. Stand at the door and look through the kiln toward the chimney. That sight line is roughly where the fire is going.
-
Front is ash, back is quiet
Nearest the firebox means the heaviest deposit, the most drips and the most risk of a pot welding down. Furthest back means dry surfaces, subtle flashing and much less drama. Neither is the good spot. They are different spots.
-
Turn each pot deliberately
Decide which face gets the flame and put it there on purpose. This is the moment the pot gets designed, more than anything you did at the wheel.
-
Use pots to shelter pots
Anything you put in front of something else casts a shadow on it. Experienced firers use this constantly, setting a tall jar to shield a row of cups so the cups get flashing instead of a face full of ash.
-
Leave the fire room to move
A wall of pots packed edge to edge will stall the kiln and cook everything in front of it while the back stays cold. Gaps are not wasted space, they are the draft.
-
Cones where you can see them
Cone packs go in front of every spy hole, front and back, because a long kiln is not one temperature. Draw rings on a wire let you hook a sample out mid firing and read how far the ash has built.
Take a photograph before the door goes up
Two minutes with a phone gives you a map of exactly where every pot stood. When you unload and one cup is extraordinary and another is flat, that photo is the only way you will ever know why. Almost nobody does this the first time and almost everybody wishes they had.
The long part
A wood firing, in six stages
Lengths vary enormously between kilns, so treat the hours below as shape rather than schedule. What does not vary is the order, or the fact that somebody is awake for all of it.
-
Preheat, and be patient
A small fire at the mouth of the firebox, sometimes for a full day, driving the last water out of the pots and the kiln itself. Rush this and you get pots exploding inside a sealed chamber you cannot open. The kiln is often still cool enough to touch at the end of it.
-
Climb
Bigger stokes, longer flame, steady rise. Somebody is watching a pyrometer and calling the pace. This is the stretch where a crew settles into a rhythm and starts trading shifts.
-
Body reduction and the long middle
Once the kiln is properly hot, each stoke chokes the oxygen and pushes the atmosphere into reduction, then it clears as the wood burns down. That cycle, over and over for hours, is what develops the iron colors. This is also where most of the ash accumulates.
-
Side stoking
Wood fed through ports along the side of the chamber, right into the ware, to put ash exactly where the front-loading firebox cannot reach. This is the most direct control anybody has over the result once the door is closed.
-
Soak and finish
Holding temperature so the back of the kiln catches up with the front and the ash on every pot has time to melt properly. Cones are read at every spy hole. The kiln is finished when the coldest part of it is done, not the hottest.
-
Cooling, which is not nothing
Clamming up the kiln and letting it fall over two to four days. Some crews reduction cool, feeding small amounts of wood on the way down to hold the atmosphere and deepen the colors. Opening early cracks pots and there is no version of this where somebody peeks.
Lindsay Oesterritter, who wrote the book most wood firers own, on the essentials of firing one of these. Watch on YouTube
A tighter twelve-minute run through the whole process, useful as a refresher the night before a firing. Watch on YouTube
The best day
Opening the kiln, and the work that follows
An unloading in full, including the pots that did not work, which is the part most videos edit out. Watch on YouTube
Unloading a wood kiln is genuinely one of the better experiences available in this craft, and it is also two more hours of work after the excitement wears off. What comes out is not finished.
- Some pots will be stuck. To the shelf, to a wad, to each other. A gentle tap with a wooden mallet frees most of them. Some do not come free, and forcing one is how you lose it and the shelf together.
- Grind every wad scar. Diamond pad, silicon carbide stone or a bench grinder, then a wet finger around the foot to find anything sharp. A pot that scratches a table gets returned.
- Check the insides for pinholes. Anything that will hold liquid gets filled with water and left overnight. If it seeps, it is a beautiful object rather than a mug.
- Photograph the whole load before it gets divided. Then compare it to your loading photo, and you have just learned more than the firing itself taught you.
- Help unload and help clean. Shelves get scraped and re-coated with kiln wash, the firebox gets shoveled out, and the wood pile gets restacked. Whether you are invited back is decided almost entirely here.
Read this one properly
Fire, fatigue and carbon monoxide
This is an open flame at 2,300 degrees, running for days, tended by people who have not slept much. It is safe when it is run properly, and every one of the rules below exists because somebody got hurt when it was not.
- Never fire indoors, and never fire alone. Wood kilns live outdoors under a roof with open sides, and there are always at least two people awake.
- Carbon monoxide is the real hazard, not the flame. A reducing kiln pours it out. That is exactly why the shelter has open sides, why nobody sleeps in an enclosed space next to the kiln, and why a headache on shift means you step away into fresh air and tell somebody.
- Cover yourself in natural fiber. Cotton or wool, long sleeves, closed leather shoes. Synthetics melt onto skin. This is not a fussy rule.
- Proper gloves and a proper face shield for the ports. Welding gloves rated for the heat, and a shield when you open a spy hole or a stoke hole. The flare-back when a door opens is instant.
- Never look into a hot kiln without shade 3 or darker. Cone 10 puts out enough infrared to damage your eyes over a firing's worth of glances. Didymium glasses are the standard answer.
- Assume every surface near the kiln is hot. Including tools you set down five minutes ago, and including the ground.
- Water, shade, food and actual sleep. Most injuries on a firing happen in hour thirty to somebody who thought they were fine. Take the shift you signed up for and then hand it over.
- Know where the extinguisher and the hose are before you need them. Ask on arrival. Sparks land on a wood pile more often than anybody likes to admit.
Nobody hands a first-timer the firebox
You will be asked to carry wood, split kindling, watch a pyrometer and learn the rhythm before you stoke anything. That is not gatekeeping. It is a several-thousand-dollar kiln load belonging to a dozen people, and the person running the firing is responsible for all of it.
Before it happens to you
Ten ways a wood firing disappoints you
Three ways a first firing disappoints you
Everybody who fires these kilns has had all of this happen. Knowing the list in advance is the difference between a disappointing unloading and an educational one.
-
Your pot is welded to the shelf
Too little wadding, wadding that was too soft, or a glaze that ran further than you expected once ash landed on top of it. More wadding, and keep glaze well up off the foot.
-
It came out dull and nothing happened to it
Almost always a refined low-iron clay with no slip on it, sitting at the back of the kiln. The clay body and the address did the deciding. Try an iron-bearing body or a flashing slip next time.
-
The inside is rough and it will not hold coffee
Bare clay inside a cup in a heavy-ash spot. Ash deposit is not a food surface. Line the insides.
-
The ash ran all the way down and glued it to its neighbor
A front-of-kiln spot with two pots too close. Ash runs downhill and it does not stop at your property line. Leave more room in the heavy zone than feels necessary.
-
One side is beautiful and the other is a blank
Working as designed. This is what a flame face is. If it bothers you, make forms that read from every angle, or ask to be loaded further from the firebox.
-
The lid is fused shut
No wadding in the gallery, or a gallery too tight to take any. Three tiny wads, every lid, every time.
-
It cracked somewhere in the long cool
Usually thin walls, an uneven thickness, or a form under tension such as a wide flat base. Wood firings are a hard ride. Build a little more forgivingly than you would for cone 5½ electric.
-
Your test tiles are unreadable
Written in pencil, or marked on the front where the ash covered it. Carve or stamp the mark, put it on the back, and keep a written map of what went where.
-
Somebody else took your pot home
No maker's mark, or one so shallow that ash filled it. Stamp deep, at leather hard, on everything.
-
You are not invited to the next one
The honest one. Wood firings run on people who turn up for the overnight shift, split wood, scrape shelves and stay to clean. Whoever does the least work and collects the most pots is a known figure, and they only do it once.
Being straight with you
Not here, and we are not going to pretend otherwise
The Clay Hole does not have a wood kiln. We have four electric kilns, including a 42 cubic foot bell lift, and we fire glaze to cone 5½. Nothing on this page happens at 12896 S Pony Express Rd, and there is no plan for it to.
The reasons are unglamorous. A wood kiln needs an outdoor site with a permanent roof, a wood yard, a permit, neighbors who are fine with smoke, and a crew willing to be awake at four in the morning on a Tuesday. Those are the conditions that make a wood kiln work, and an industrial suite off I-15 has none of them.
So why write all this? Because members ask about these pots constantly, because a good number of you will end up at a university firing or a workshop or a friend's kiln at some point, and because knowing how a surface got made changes how you look at every pot, including the ones you make here. Learning a process is not the same as having access to one.
If you want the closest thing we do run: our raku workshops are a real atmospheric firing with real fire and real tongs, and they are the only place in our calendar where the kiln, rather than the glaze bottle, decides how your pot turns out.
Asked at the glaze table
Wood firing questions we get
Mostly from members who saw a pot somewhere and wanted to know how the color got on it.
How do I get into a wood firing in the first place?
University ceramics departments, craft schools and a handful of private studios run them, and most of them need bodies. Turn up to help load and stoke without asking for kiln space, do it well, and you will be offered space. That is the standard route and it works.
Anywhere with an anagama, a train kiln or a noborigama is worth an email. Regional wood-firing groups and ceramics guilds usually keep a list of firings looking for crew.
Is it expensive?
Usually you pay a firing fee based on how much kiln space you take, and you pay in labor as well. The fee covers wood, kiln wash, shelf repair and the fact that these kilns wear out. The labor is not optional and it is a bigger cost than the money.
Can I get a wood-fired look out of an electric kiln?
You can get somewhere in the neighborhood with ash glazes, iron-rich glazes and layering, and there are glazes on our wall that read as warm and toasty in that direction. Look at the fluxes over an iron-bearing clay.
But no. The two effects that actually define a wood-fired pot, ash landing where the flame decided and reduction color from a starved atmosphere, both need a fuel-burning kiln. An electric kiln has an oxidizing atmosphere and nothing floating around in it. Getting close is a legitimate goal. Claiming a match is not.
Is a wood-fired pot food safe?
The clay is vitrified at cone 10 or above, so the body itself is dense. The question is the surface. A bare ash-deposited interior can be rough and pinholed, which makes it hard to clean rather than toxic. That is why nearly everybody puts a tested liner glaze inside cups and bowls.
Fill anything that holds liquid with water and leave it overnight before you call it finished.
What is the difference between wood firing and salt or soda firing?
Both are atmospheric, meaning the kiln makes the surface rather than the glaze bucket. In wood firing the glass comes from ash carried by the flame. In salt and soda firing somebody introduces sodium deliberately near the end and it welds into the clay surface as glass.
Plenty of kilns do both, wood fired and then salted or sodaed at the top. Our salt and soda page covers that side in the same detail as this one.
Why does everybody talk about pine?
Softwoods like pine burn fast with a long flame, which is what you want for reaching temperature and pushing fire deep into a long chamber. Hardwoods burn slower and hotter with more ash per log. Different woods also leave different ash chemistry and therefore different colors, which is why some kilns are fussy about the species and the fruitwood pile is guarded.
All of it must be properly seasoned. Wet wood does not fire a kiln, it steams.
How many pots come back looking good?
Ask ten wood firers and you will get ten answers, most of them lower than you expect. The honest framing is that a firing gives you a small number of pots you could not have made any other way, a larger number that are decent, and some that are firewood. That trade is the entire proposition. People who need every pot to work fire electric, and they are not wrong to.
Not instructional, just very good
Four films worth an evening
These will not teach you to wad a lid. They will show you what a life spent at one of these kilns looks like, which is the part that makes people want to do it.
Nic Collins in Devon, firing an anagama he built himself. Twenty minutes and probably the best short film about wood firing on the internet. Watch on YouTube
Ken Matsuzaki in Mashiko. A feature-length look at a Japanese potter working in the tradition these kilns came from. Watch on YouTube
Lee Kang-hyo throwing enormous onggi jars and firing them in a Korean wood kiln. Worth it for the slip decoration alone. Watch on YouTube
A fifteen-minute documentary short following one anagama firing from loading to unloading. Watch on YouTube
More where that came from
Our curated ceramic artist videos page is hours deep in this sort of thing, sorted so you spend the evening inspired rather than searching.
Keep going
Six pages that pair with this one
Three pages that pair with this one
Everything here lives in Clay Hole University, which is where all of our teaching pages are gathered.
Salt and soda firing
The other way a kiln makes its own glaze, and the one most often paired with wood.
What a kiln firing actually does
The chemistry underneath every firing on this list, including the ones we run here.
Clay Hole University
Every lesson we have written, in order, from wedging to the kiln.
Pit firing
Wood firing stripped back to a hole in the ground, and the cheapest way to try fire as a decorator.
Prepping and testing wild clay
How to find out what a local clay will survive, which matters more here than anywhere.
Raku firing
The atmospheric firing you can actually get to through us, and the one we certify members for.
Last thing
You are not glazing the pot. You are aiming it.
You are not glazing the pot. You are aiming it.
Every habit worth having in a wood kiln comes from the same shift in thinking. In an electric firing you decide what the surface will be and the kiln carries out the instruction. In a wood firing you set up conditions, hand the pot to the fire, and find out three days later what it decided. The skill is in the setup: the clay you chose, the form you gave the ash to run over, the slip, the wadding, and the address you picked in the kiln.
That is also why people get slightly obsessive about it. You cannot make the same pot twice, and neither can anybody else.
None of this happens here, and it is still worth knowing. The next time you pick up a wood-fired cup, turn it over, find the three wad scars, work out which side faced the fire, and you will be reading it instead of just liking it.
In an electric firing you decide what the surface will be and the kiln carries out the instruction. In a wood firing you set up conditions and find out three days later what the fire decided. The skill is all in the setup: the clay, the form, the slip, the wadding, and where in the kiln your pot stands.
There is a much longer version of this page if you want it. Hit Comprehensive at the top.
Which version would you like to print?
Videos come out as a labelled box with the title and channel to search for, since paper does not play them.