To Techniques

Saggar firing is a low-tech, high-reward ceramic technique in which a bisque-fired pot is wrapped or packed together with combustible and mineral materials inside a sealed container called a saggar, then fired. The materials inside react with the clay surface during the burn, leaving unrepeatable clouds of colour, smoky blacks, and organic markings with no glaze involved at all.

Where Saggar Firing Comes From

The word "saggar" comes from a much older, entirely practical tradition: potters protecting delicate glazed ware from direct flame and ash inside wood-fired and coal-fired kilns, by enclosing it in a fireproof clay box — the original saggar. For centuries this was purely functional, a way to keep smoke and soot off fine porcelain.

Contemporary saggar firing flips that original purpose on its head. Rather than trying to keep smoke and flame effects out, today's ceramic artists deliberately pack the saggar with materials chosen to stain, smoke, and mark the pot — turning what was once a protective barrier into the whole point of the firing. It produces a distinctly different look to raku: softer, more painterly, closer to watercolour than crackle glaze.

How the Process Works

1. Bisque fire first — as with raku, the piece must already be bisque-fired; saggar firing works on bare, unglazed clay.

2. Prepare the surface — burnishing or applying a fine terra sigillata slip beforehand helps the surface take colour more vividly. The bisqueware can also be dipped in ferric chloride at this point for more effects

3. Pack the saggar — the pot is wrapped in combustible material combined with colourants, all wrapped in tinfoil.

4. Fire it — the packed saggar goes into a kiln or pit fire and is fired to a relatively low temperature, typically 700–950°C.

5. Let it cool slowly — the saggar is left to cool naturally with the kiln or pit fire, unopened, so smoke and vapour keep reacting with the surface.

6. Unwrap and reveal — opening the saggar is the payoff moment, pulling back ash to see exactly how the colours and marks landed.

What Creates the Colour and Marking

• Copper carbonate — vivid reds, oranges, and turquoise blooms

• Seaweed — soft pinks and organic mottling, rich in natural sodium

• Banana skins — subtle blush tones from potassium content

• Salt — sharp white or pale flashing where it touches the clay

• Sawdust and newspaper — the smoky black base tones that frame the colour

• Ferric Chloride — browns, ochre, oranges

Is Saggar-Fired Pottery Food Safe?

No. Like raku, saggar-fired pieces are unglazed, porous, and not intended for food or liquid contact. These are decorative and sculptural works — vessels, wall pieces, sculptural forms — valued for their surface, not their function.

What You Need to Try It

• Bisque-fired stoneware, burnished or with a terra sigillata surface for best colour results

• A saggar — a lidded, fireproof container sized to your piece

• Packing materials: combustibles and colourants like copper carbonate, cobalt carbonate, or salt

• A kiln capable of a slow, controlled low-temperature firing or pit fire

• Gloves and basic fire safety precautions when packing and unpacking

Saggar firing is gentler than raku in some ways — no red-hot tongs, no open flame pull — but it rewards patience. Results depend heavily on packing technique, and that only comes with practice and observing what each material does.

Try It Yourself

I run saggar-firing workshops at my studio in Koringberg, in the Swartland, about an hour from Cape Town — often alongside raku and pit-firing in the same weekend session. No experience is necessary; I provide the pit fire, saggar containers, and packing materials, and guide you through building your own combination of colourants and combustibles.

See Saggar Workshops

Frequently Asked Questions

Can beginners do saggar firing?

Yes. It's one of the more accessible alternative firing techniques since there's no open flame handling involved — you're packing a container, not pulling red-hot ware from a kiln.

How is saggar firing different from raku?

Raku involves pulling glazed, glowing-hot pots directly from the kiln into combustible material for a fast reduction. Saggar firing packs unglazed pots with colourants and combustibles inside a sealed container before firing, at a lower temperature, with no dramatic hot-pull moment.

What temperature is saggar firing done at?

Typically 700–950°C — lower than a standard glaze firing and gentler than raku's peak temperature.

Can I reuse saggar materials?

Spent packing material generally loses its potency after one firing and is usually discarded, though some potters experiment with partial reuse to see how a "second generation" burn behaves.

How long does a saggar firing take?

Longer than raku in total time, since the piece needs to cool slowly inside the sealed saggar rather than being pulled hot — a full cycle including cooling can take several hours to overnight.