How Long Does Pottery Take To Fire?
By Linda · · 8 min read
How long does it take to fire pottery?
Firing pottery takes roughly 14 to 24 hours of total kiln time across two firings: a bisque firing of 8-12 hours and a glaze firing of 6-12 hours. Add cooling time, which roughly doubles each firing, and each kiln load takes about a full day from loading to unloading. The exact time depends on your kiln, the cone you’re firing to, and how thick your pieces are.
That answer surprises a lot of beginners. The kiln isn’t like an oven where you bake something for 45 minutes. Clay has to climb slowly through several critical temperature zones, and then it has to cool just as carefully. Rushing either direction is how pieces crack or explode in the kiln.
How Long Does a Bisque Fire Take?
A bisque firing typically takes 8 to 12 hours to reach temperature, plus another 10 to 12 hours of cooling before you can safely open the kiln. So from loading to unloading, plan on a full 24 hours.
Bisque is deliberately the slower of the two firings. Even bone-dry clay still holds chemically bonded water, and that water has to escape as steam without blowing the piece apart. Most potters bisque to cone 06-04, around 1830-1945°F (999-1063°C).
A typical electric kiln bisque schedule looks like this:
- Optional preheat (candling): 2-8 hours holding around 180-200°F (82-93°C) to drive off any remaining moisture. I always candle overnight for thick or questionable pieces.
- Slow climb to 1100°F (593°C): roughly 150-200°F per hour. This is the danger zone. Steam release and quartz inversion both happen here.
- Faster climb to final temperature: the kiln can speed up once the water is gone.
If your pieces are thick, hand-built, or you suspect they’re not fully dry, slow down and candle longer. A piece can’t really be too dry to fire, but it can absolutely be too wet.
How Long Does a Glaze Fire Take?
A glaze firing takes about 6 to 8 hours for low-fire earthenware (cone 06-04) and 8 to 12 hours for mid-range and high-fire stoneware or porcelain (cone 5-10). Cooling adds another 12 hours or more.
Glaze firings can climb faster in the early stages because the bisque pottery has already had its water driven off. What takes the time is the higher target temperature (cone 6 is about 2232°F / 1222°C, and cone 10 is around 2345°F / 1285°C), plus any holds or slow segments at the top to let the glaze melt and smooth out properly.
Many potters add a 10-15 minute hold at peak temperature to heal pinholes in the glazed surface. Some also slow the cooling between about 1900°F and 1400°F (1038-760°C) to develop matte or crystalline glaze effects, which can add several hours.
Don’t Forget Cooling Time
Cooling is the part nobody warns you about. A kiln that took 8 hours to fire will take 12 to 24 hours to cool naturally, depending on its size and how tightly it’s packed. A big, densely loaded kiln holds heat like a thermos.
The rule most potters follow: don’t open the lid until the kiln is below 150-200°F (66-93°C), cool enough that you can comfortably hold your hand near the pieces. Cracking the lid at 500°F because you’re impatient is a classic way to craze glazes or crack ware through thermal shock. I’ve done it. Once.
Firing Times at a Glance
| Firing stage | Cone | Approx. temperature | Firing time | Cooling time |
|---|---|---|---|---|
| Bisque | 06-04 | 1830-1945°F (999-1063°C) | 8-12 hours | 10-12+ hours |
| Low-fire glaze | 06-04 | 1830-1945°F (999-1063°C) | 6-8 hours | 10-12+ hours |
| Mid-range glaze | 5-6 | 2167-2232°F (1186-1222°C) | 8-10 hours | 12-16+ hours |
| High-fire glaze | 9-10 | 2300-2345°F (1260-1285°C) | 10-12+ hours | 16-24+ hours |
These are realistic ranges for a typical electric kiln. Gas, wood, and very large kilns run on their own timelines. A wood firing can take several days of round-the-clock stoking.
What Affects How Long a Kiln Takes to Fire
No two kilns fire on exactly the same clock. The biggest variables:
- Kiln size and age. A small test kiln can reach cone 06 in 4-5 hours; a large production kiln may need 12+. Worn elements in an electric kiln slow the climb dramatically, especially near top temperature.
- Target cone. Every cone higher means more climbing time. Cone 10 takes noticeably longer than cone 6, which takes longer than cone 04. If you’re unsure what temperature your clay needs, start with how hot a kiln needs to be for pottery.
- How full the kiln is. A densely packed load absorbs more heat and fires slower. It cools much slower, too.
- Wall thickness. Thick, chunky pieces need slower ramps so heat penetrates evenly. I slow my bisque by a third for anything over an inch thick.
- Programmed speed. Digital controllers usually offer slow, medium, and fast schedules. “Fast” saves a couple of hours but raises the risk of defects; I only use it for thin, fully dry work I’ve fired before.
- Kiln type. Electric kilns follow the controller. Gas kilns depend on the operator and often run 8-12 hours for a cone 10 reduction firing. If you’re firing a small gas kiln, prop the lid open a few inches and start on a low flame to avoid thermal shock early on.
The Complete Timeline: From Wet Clay to Finished Piece
Firing is only part of the journey. From a fresh lump of clay to a finished glazed pot, expect two to three and a half weeks:
- Making the piece: 1-2 days
- Drying to bone dry: 2-7+ days, depending on thickness and humidity (see how long pottery takes to dry)
- Bisque firing + cooling: about 24 hours
- Glazing: half a day to a day
- Glaze drying: a few hours to overnight
- Glaze firing + cooling: 24-36 hours
In a community studio, the real-world wait is usually longer, because studios fire kilns only when they’re full. Two to four weeks from drop-off to pickup is normal. Worth knowing if you’re hunting for a place to fire your pottery.
Why You Can’t Just Fire Faster
Three things happen inside the clay that physically limit your speed:
- Water smoking (up to ~660°F / 350°C). Any remaining mechanically held water escapes as steam. Heat too fast and the steam pressure blows the piece apart.
- Burnout and dehydroxylation (~570-1470°F / 300-800°C). Organic material and carbon burn off, and the chemically bonded water leaves the clay. Trapping carbon by rushing can cause bloating and black coring, especially in dark stoneware.
- Quartz inversion (~1063°F / 573°C). The silica in clay changes crystal structure and the piece suddenly expands slightly, then shrinks again at the same point on the way down. Passing through this zone too fast, in either direction, causes cracks. It’s also part of why pottery shrinks when fired.
This is also why a kitchen oven can never replace a kiln. An oven tops out around 500°F (260°C), far below the temperatures clay needs to become ceramic. I cover the details in can you fire pottery in an oven.
Linda’s Practical Schedule
For what it’s worth, here’s the rhythm I’ve settled into with my mid-size electric kiln at home:
- Load the bisque in the evening, candle overnight, start the slow program at breakfast. It reaches cone 06 by late afternoon and I unload the next morning.
- Glaze fire on a medium-speed cone 6 program started first thing in the morning. It’s done by dinner and unloaded the following afternoon.
If you’re setting up your own kiln, my guide to firing pottery at home walks through the whole process step by step.
FAQ
How long does it take to fire pottery in a kiln?
Each firing takes 6 to 12 hours of heating plus 10 to 24 hours of cooling, so plan on roughly 24 hours per kiln load. Since pottery is normally fired twice, once for bisque and once for glaze, the total kiln time for a finished piece is about two days.
How long does a bisque fire take?
8 to 12 hours to reach cone 06-04, plus 10-12 hours of cooling. Thick or freshly dried work needs a slower schedule, and many potters add a preheat hold of 2-8 hours to drive off residual moisture.
How long does it take to glaze fire pottery?
About 6-8 hours for low-fire work and 8-12 hours for cone 5-10 stoneware or porcelain, plus a cooling period that’s usually longer than the firing itself.
How long does a kiln take to fire if it’s electric vs. gas?
A programmed electric kiln runs largely on autopilot for 6-12 hours depending on the schedule and cone. Gas kilns typically take 8-12 hours for a cone 10 firing and need an operator adjusting burners and dampers throughout.
How long does it take to fire ceramic at home without a kiln?
Alternative methods like pit firing or raku take 2-8 hours of active firing, but they only suit specific clays and finishes, and the results aren’t food-safe or fully vitrified. See how to fire pottery without a kiln for what’s realistic.
Can I speed up firing by opening the kiln early?
No. Opening above about 200°F (93°C) risks cracking ware and crazing glazes from thermal shock. The cheapest way to “speed up” is simply to fire thinner, fully dry work on a medium schedule rather than gambling with a fast one.
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