To make clay at home for pottery you have two real options: dig and refine wild clay from the ground, or mix dry clay powder with water. Wild clay takes days of soaking, sieving and drying, and you then test fire a small tile to find out how hot it can go. Dry clay powder is faster and predictable, but it is dusty, so you mix it wet or outdoors with a respirator. Recipes for flour or cornstarch "clay" make a craft dough, not pottery clay.
This guide walks through processing wild clay step by step, testing it, mixing clay powder safely and what homemade dough can and cannot do. It is research-based: we compared published guides from ceramic educators and potters and did not process clay ourselves. Wild clay is unpredictable, and nothing here promises that a clay you dig will be safe to fire or food safe.
Three things "making clay at home" can mean
- Wild clay: natural clay you dig and clean up yourself. Real pottery clay, but with an unknown firing range.
- Mixing clay powder: a commercial dry clay body or raw clay (such as Redart or Goldart) mixed with water. Real pottery clay with a known cone, covered in the safety section below.
- Craft dough: flour, salt, cornstarch or glue recipes. Fine for kids' crafts, but it cannot go in a kiln.
Step 1: Find clay in the ground
Clay is the fine, sticky part of soil. Look where water or digging has exposed the layers below the topsoil: stream and river banks, road cuts, eroded gullies, construction spoil and the subsoil in your own yard. It is often gray, yellow, red or brown and feels smooth and slick when wet, not gritty.
Get the landowner's permission before you dig, and check local rules for parks and public land, where digging is often banned. Avoid ground that may be polluted, such as old industrial sites, dumps or ditches that collect road runoff.
The coil test
Wet a pinch of the soil, roll a pencil-thick coil and bend it around your finger. Good throwing clay bends with only fine cracks. A coil that breaks apart has too much sand or silt; it may still work for hand-building or as part of a blend.
Step 2: Dry it and slake it
Break the clay into small pieces and let them dry completely. Bone-dry clay soaks up water faster and more evenly than damp lumps. Drop the dry pieces into a bucket of water, cover it and leave it: this is slaking. Small pieces fall apart within hours; hard lumps can take days. Stir or blend into a thin, creamy slurry, adding water as needed. A paint-mixing paddle on a drill speeds this up.
Step 3: Sieve out stones, roots and sand
Pour the slurry through a coarse screen first (window screen works) to catch stones, roots and leaves, then through finer sieves. Many potters finish with a 60 mesh sieve for throwing clay. Rinse sieves right away, before clay dries in them. Always sieve wet: Digitalfire notes that dry powder cannot be screened much finer than about 50 mesh, and dry screening throws up dust.
Step 4: Settle it and dry it back to working clay
- Leave the sieved slurry to settle for a day or more, then siphon or pour off the clear water on top.
- Pour the thick slip into a cotton pillowcase or cloth bag and hang it over a tub to drain, or spread it on a plaster slab or plaster bat, which draws water out.
- Turn and fold it as it firms. Published accounts describe this stage taking from a few days to about 10 days, depending on the weather.
- When it no longer sticks to your hands, wedge it well to even out the moisture and remove air; see how to wedge clay.
- Bag it airtight. Many potters let new clay age for a few weeks, which often improves plasticity.
Step 5: Test fire a test tile
Never fire a pot from untested wild clay. Many wild clays are high in iron and other fluxes and can slump, bloat or melt at temperatures commercial stoneware handles easily. Make several flat test tiles about 4 in long and 1/4 in thick, mark each one, and let them dry completely.
- Fire the tiles inside a bisqued bowl or on a scrap shelf, never directly on a good kiln shelf. If the clay melts, it melts into the bowl.
- Start low: a first firing at about cone 06 to 04, 1,828°F to 1,945°F (998°C to 1,063°C), tells you whether the clay survives earthenware temperatures.
- Step up one range at a time on new tiles. Stop at the first sign of bloating, slumping, blistering or glassy melting; that is the clay's ceiling.
Ask your studio or kiln owner first, since a melted tile can damage elements and shelves. A small test kiln makes this easier if you plan to experiment often.
Shrinkage test
On each wet tile, scratch a line exactly 100 mm long (about 4 in; metric keeps the math easy). Measure the line after drying and after firing. Shrinkage is (100 minus fired length) divided by 100, times 100. A line that fires to 88 mm means 12% total shrinkage, which is in the normal range for stoneware. Our clay shrinkage guide explains what the numbers mean for your pots.
Absorption test
Weigh a fired tile dry. Soak it in water for 24 hours (or boil it, which gives a more complete reading), pat it dry and weigh it again. Absorption is (wet weight minus dry weight) divided by dry weight, times 100. High absorption, above about 10%, means a porous, earthenware-like body; very low absorption means it is close to vitrified at that cone.
Improving a wild clay
Few wild clays are perfect as dug. Common fixes are adding sand or grog to cut shrinkage and cracking, blending in commercial ball clay for plasticity, or mixing the wild clay with a known commercial body so the blend fires more predictably. Change one thing at a time and make new test tiles for each blend.
Mixing clay powder for pottery safely
Dry clay powder is the easier way to make clay at home, and a dry commercial body comes with a known cone. The risk is dust: clay powder contains crystalline silica, and breathing fine silica dust over time can cause serious lung disease.
Mix clay powder wet or outdoors, and wear a NIOSH-approved respirator rated for fine particles, properly fitted, whenever you open, pour or mix dry materials. Add powder slowly to water rather than water to powder, keep your face away from the bucket, and work where dust will not spread into the house. Clean up with a wet sponge or mop, never dry sweep or use an ordinary shop vacuum. Read the supplier's safety data sheet for each material.
Our powdered clay guide covers water ratios, mixing by hand and which dry bodies to buy, and our clay dust safety guide goes deeper on protecting your lungs.
Homemade "clay" from flour or cornstarch is not pottery clay
Search for homemade clay and most recipes use kitchen ingredients. The Mint Museum's three-ingredient recipe uses flour, salt and cold water, air dried or baked in a home oven at 300°F. Cold porcelain uses cornstarch and glue, and baking soda dough uses baking soda and cornstarch. These are fun for kids and display pieces, but they are not clay minerals at all.
- They burn rather than fire, so they must never go in a kiln.
- They soften in water and are not food safe.
- They do not throw on a wheel the way clay does.
For kids' projects, see our clay projects for kids guide.
Is wild clay safe to fire and use?
There is no way to know without testing, and even testing has limits. Wild clay can contain organic matter, sulfur and carbonates that burn off as fumes in the kiln, and lime particles can pop out of fired pieces later. Fire it in a vented kiln, following the kiln maker's instructions, and only after small test tiles. We cannot tell you any wild clay is food safe; for food use, potters rely on tested commercial bodies and glazes.
Common mistakes
- Firing a full pot of untested wild clay on a bare kiln shelf.
- Sieving dry clay and breathing the dust.
- Pouring clay slurry down the drain.
- Skipping wedging, which leaves air pockets and wet spots.
- Putting flour or cornstarch dough in a kiln.
- Digging on land without permission.
What you need
For wild clay: buckets, a coarse and a 60 mesh sieve, cloth bags or a plaster slab, and access to a kiln for test tiles. For powder: a respirator and a place to mix wet. If you would rather start with clay that just works, our best clay for pottery guide compares bagged beginner clays.
Sources: Ceramic Arts Network, "Going Local: How to Dig and Process Your Own Clay"; The Pottery Wheel, "How to Make Clay from Dirt"; Instructables, "Finding and Processing Your Own Natural Clay"; Mint Museum, three-ingredient clay recipe; Digitalfire, "Specking on ceramic ware" (sieving dry powder); OSHA crystalline silica fact sheet; Orton cone temperature chart. Specs checked October 2026.