Quick answer: Yes, pottery is fired twice as a standard process. The first firing (bisque) hardens raw clay at around 1850°F. The second firing (glaze) melts the glaze coating at 2150 to 2350°F. You can also refire a piece a third or fourth time to fix glaze defects, missed spots, or surface flaws, but each refire stacks risk: cracking, color shifts, and bloating all get more likely with each pass through the kiln.
That short answer covers the question most beginner potters are asking. The longer answer matters when you have a specific piece in front of you with a specific problem. The rest of this guide breaks down the standard twice-fired cycle, the rules for refiring already-glazed pieces, and what can go wrong each time you put a piece back in the kiln.
The Standard Twice-Fired Pottery Process
Most pottery you see in galleries, restaurants, and homes has been fired exactly twice. That is the baseline ceramic process, not an exception. The two firings serve completely different purposes, run at different temperatures, and produce different results.
First firing: bisque
Bisque firing converts raw plastic clay into a hard, porous ceramic. Greenware (unfired clay) goes into the kiln, the temperature climbs slowly to around 1850°F (cone 06 to 04), and the chemical structure of the clay permanently changes. Water and organic matter burn off, the clay particles fuse, and what comes out is a hardened piece that will never return to a workable plastic state. The bisque-fired piece is still porous enough to absorb glaze evenly, which is why the second firing is necessary to seal it.
Second firing: glaze
After bisque, the potter dips, brushes, or sprays a liquid glaze onto the piece. That glaze is essentially a thin layer of glass-forming minerals. The piece goes back in the kiln, this time to a higher temperature, typically 2150 to 2350°F (cone 5 to 10 for stoneware and porcelain, lower for earthenware). At those temperatures the glaze melts into a glassy surface, fuses to the clay body, and produces the finished waterproof ceramic. For a deeper look at the glaze side of this step, see our breakdown of what is glazing in pottery.
Why both firings matter
Skipping bisque is technically possible (called single-firing or once-firing), but it is much harder for beginners because the glaze has to be applied to leather-hard greenware without causing the piece to slake apart. Skipping the glaze firing means you end up with a porous, unfinished bisque piece that holds water but lets it slowly seep through. Almost every functional pottery piece you have ever owned was fired twice as the standard process.
Pottery Firing Stages at a Glance
The visible difference between the firing stages is striking once you see them side by side. Raw greenware is soft, matte, and slightly damp-looking. Bisque-fired pottery is hard but matte, often a buff or peach color depending on the clay body. Glaze-fired pottery has the rich shine, color, and finished feel that comes from melted glass on the surface.
Can You Refire Already-Glazed Pottery?
This is the question most people are actually asking when they search “can you fire pottery twice.” Yes, you can put a piece that has already been glaze-fired back into the kiln for a third or fourth time. Digitalfire’s technical glossary on refiring notes that this is common and well-understood in ceramics, but with real caveats. Each refire is a fresh stress test on the piece.
Common reasons to refire a glazed piece
- Missed glaze spots: a bare patch where the glaze did not cover properly. Touch up the spot with more glaze and refire.
- Glaze defects: crawling, pinholing, or crater spots in the finished surface. A second glaze fire at the same temperature often fixes the worst of it.
- Adding decals or lusters: china paints, gold lusters, and decorative decals require an additional low-fire pass at 1100 to 1400°F after the main glaze fire.
- Adding a second glaze layer: building up color, gloss, or texture by layering glazes is a deliberate technique that requires multiple firings.
- Forgot to glaze the inside: a frequent beginner issue. The fix is to glaze the missed area and refire.
What changes on the second glaze fire
The piece has already been through its peak temperature once. The glaze is already vitrified. Sending it back through the kiln means the clay body gets re-stressed by another full thermal cycle, the glaze re-melts and may flow differently, and any chemistry that was borderline the first time gets pushed further. Practitioner forums like r/Pottery and Ceramic Arts Daily have decades of accumulated experience on specific refire scenarios if you face an unusual case.
How to Refire Pottery Safely
Refiring is not casual. It works, but the rules are stricter than the original glaze fire. Following these will save you from cracked or ruined pieces.
Cool completely before doing anything
Never reglaze a piece that is still warm from the kiln. Glaze needs to bond to a cool surface, and applying it to a hot piece causes uneven coverage and crawling. Wait until the piece is fully at room temperature, usually 24 hours after the kiln unloads.
Clean and prep the surface
Wipe the piece with a damp sponge to remove any dust or kiln debris. If you are reglazing over an existing glaze (rather than just touching up a bare spot), the original glaze surface may need a light sanding to give the new layer something to grip. Glaze does not stick well to a glass-smooth surface; it needs slight texture.
Match or lower the firing temperature
If your original fire was cone 6, your refire should be cone 6 OR slightly lower. Going higher pushes the original glaze chemistry past its design temperature and risks bubbling, running, or worse. For decals and lusters, the refire is much lower (cone 018 to 014), well below the glaze maturation temperature, so the existing glaze stays intact while the new surface treatment fires on.
Fire slowly through critical zones
Already-fired pieces are more vulnerable to thermal shock than greenware was. Use a slower ramp through the silica inversion zones (around 1063°F on the way up, 437°F on the way down). A 2-hour climb to cone 6 that worked the first time should become a 3 to 4 hour climb on the refire.
What Can Go Wrong With Refiring
The risks of refiring are real but predictable. Each one has a cause and a workaround.
Cracking from thermal shock
The piece has been through one full heat-and-cool cycle already. Each additional cycle adds stress to the clay body, particularly at the silica inversion points where the crystalline structure shifts. Cracking risk is highest with thin walls, sharp corners, and rapid firing schedules. Slow your ramp and slow your cool to reduce this.
Color shifts and burnout
Red and copper glazes are the worst offenders. Reds can burn out completely to brown or gray on a second fire. Copper greens can shift to dark olive or black. Iron-bearing glazes can saturate. Pottery Presents’ guide on multiple firings covers the practical fix: avoid refiring sensitive colored pieces unless you know the glaze formula handles it.
Bloating in dark clay bodies
Brown and red clay bodies contain iron and organic matter that release gas during firing. The first firing handles most of this, but a second high-fire can push remaining materials past their tolerance, producing surface blisters or full-on bloating (puffy raised spots). White clay bodies and porcelain are much more forgiving on the second fire because they have less to outgas.
Glaze running and pooling
A second melt is a second chance for glaze to flow. If your glaze was already at the high end of its melt range on the first fire, the second can push it past flow and into running. Pieces in the kiln need to be on cookies or kiln-stilts during refires to protect the kiln shelves from glaze drips.
Can You Bisque Fire Pottery Twice?
Different question, different rules. Refiring a bisque piece (one that has not yet been glazed) is much lower risk than refiring a glazed piece. The clay body has hardened but the surface has nothing on it to react. People bisque fire twice when the original bisque did not reach temperature (kiln malfunction, controller error), or when greenware was loaded incorrectly and stacked under-fired pieces.
White clay bodies handle a second bisque firing with almost no risk. Brown and red bodies are slightly more sensitive due to iron content but still mostly fine. If your bisque came out softer than expected (chalky, easily scratched), running it through a second bisque cycle is a normal fix.
Pottery Firing Temperature Reference
The table below covers the temperature ranges and cone numbers you will encounter in standard pottery firing. Use this as a reference before loading any kiln.
| Firing Stage | Temperature Range | Cone | Purpose | Refire Risk |
|---|---|---|---|---|
| Decal / Luster Fire | 1100 to 1400°F | 018 to 014 | Apply decals, gold lusters, china paint over existing glaze | Low (well below glaze melt) |
| Low Bisque | 1828°F | 06 | Hardening greenware to porous ceramic, preferred for absorbent glaze application | Very low |
| Standard Bisque | 1888°F | 04 | Standard hardening fire, slightly denser than cone 06 | Very low |
| Earthenware Glaze | 1922 to 2080°F | 04 to 1 | Glaze maturation for low-fire pottery, terra cotta, decorative ware | Moderate |
| Stoneware Glaze | 2167 to 2232°F | 5 to 6 | Standard stoneware glaze maturation, most home and studio work | Moderate |
| High-Fire Stoneware / Porcelain | 2300 to 2381°F | 9 to 10 | Functional porcelain and high-fire stoneware glaze maturation | High (any further refiring stresses the body significantly) |
How This Differs From “How Many Times Can You Fire Pottery”
People often ask both questions interchangeably, but they have different answers. This article answers can you fire a piece more than once (yes, with rules), which is the most common scenario. The related question of how many times you can keep firing a single piece is more about how much thermal stress a clay body can take before it fails. The realistic upper limit is around 4 to 5 firings for most clay bodies, with diminishing margin each time. For the full breakdown on cumulative firing limits, see our companion guide on how many times you can fire pottery.
Related Considerations
A few related issues come up often enough to be worth flagging. If your greenware is not fully dry before bisque, see our guide on how dry pottery should be before firing. If you are still working out the basics of the firing process itself, our complete guide to how to fire pottery covers the full standard cycle. And if you are choosing a clay body and want to know which ones handle multiple firings best, our overview of different types of pottery clay and their uses compares the major options.
Frequently Asked Questions
Can you refire glazed pottery?
Yes. The most common refire scenarios are fixing missed glaze spots, adding decals or lusters, and applying a second glaze layer for color depth. Match or slightly lower the original firing temperature, fire slowly through the critical ramp zones, and expect more risk than the first firing.
Can you fire pottery without glazing it?
Yes, but the result is bisque-fired pottery which is porous and not waterproof. Bisque-only pieces are suitable for decorative use, planters with drainage trays, or any non-functional purpose. For dinnerware, mugs, or anything holding liquid, the second glaze firing is required.
How long do you wait between bisque and glaze firing?
Practically, as long as it takes you to glaze the piece. Once bisque-fired and cooled, the piece is stable indefinitely and can sit on a shelf for weeks or months before glazing. Glaze application itself takes minutes to hours depending on technique, then the piece can go directly back in the kiln for the glaze fire.
What happens if you fire glaze at too high a temperature on a refire?
The glaze can become over-fired: running off vertical surfaces, blistering, color burning out, or pooling at the bottom of the piece. In bad cases the glaze can fuse the piece to the kiln shelf, requiring damage to remove. Stay at or slightly below the original cone temperature.
Can you refire a cracked piece?
Probably not usefully. A cracked piece will not heal in the kiln, and the heat cycle of a refire will usually make existing cracks worse or propagate them. The exception is hairline craze cracks in the glaze surface (not the clay body) which can sometimes be smoothed by a careful refire at the original cone temperature.