How to Care for Japanese Ceramics: Seasoning, Washing, and Everyday Habits
A well-made Japanese bowl is tougher than it looks, but it does keep asking for small attentions. Most of what people call “delicate” about Japanese ceramics is really just unfamiliarity — a handful of habits that are second nature in a Japanese kitchen and easy to miss everywhere else. Learn them once and a good piece will outlast you, gathering the soft patina the Japanese call nagori, the trace of use.
How you care for a piece depends almost entirely on what it is made of, so this guide starts there, then works through the first wash, everyday cleaning, drying and storage, stains and crazing, and the honest truth about dishwashers, microwaves, and repairs.
Start with what it is made of
Before you wash anything, it helps to know whether you are holding earthenware or porcelain, because the two behave very differently around water and heat.
Earthenware and stoneware — tōki and sekki — are fired at lower temperatures, roughly 1,000 to 1,300°C. The clay stays slightly porous even under a glaze, which is why these pieces feel a touch warmer and lighter in the hand, sound dull when tapped, and can slowly drink up liquid. Porcelain — jiki — is fired hotter, around 1,250 to 1,400°C, until the body vitrifies into something dense and almost glassy. It is heavy for its thinness, often faintly translucent at the rim, and rings with a clear note when you tap it.
A quick test settles most cases: turn the piece over and look at the unglazed ring on the base. Coarse, earthy, matte clay means earthenware or stoneware that will appreciate a little seasoning. Fine, white, nearly glassy clay means porcelain, which needs far less fuss.
The first wash, and whether to season it
New porous pieces benefit from a traditional seasoning called medome (目止め) before their first real use. The idea is simple: you fill the open pores of the clay with starch so the piece resists stains, odors, and the discoloration that can otherwise settle into fine glaze cracks over the years.
To do it, submerge the piece in a pot of rice-washing water — the cloudy togijiru left over from rinsing rice — or plain water with a spoonful of rice or flour stirred in. Bring it to a gentle simmer for fifteen to twenty minutes, turn off the heat, and let everything cool to room temperature with the piece still resting inside. As it cools, the starch works its way into the clay. Then rinse, and let it dry completely before it goes away.
Porcelain skips this step entirely — a vitrified body has almost nothing for the starch to fill. If you are unsure which you have, it is safe to season anyway: it does no harm to a glazed earthenware bowl and can spare you a permanent tea stain down the line.
Washing, day to day
Hand-washing is the whole secret to longevity. Warm water, a soft sponge, and a little mild dish soap handle almost everything. Leave the abrasive scouring pads and gritty cleansers in the cupboard, since they dull glazes and scratch any gold or silver painting.
Unglazed clay asks for one extra courtesy: keep soap off it. The bare interior of many kyusu teapots and the exposed foot ring of earthenware will absorb detergent the way they absorb tea, and the taste lingers. Rinse those parts with plain water and a soft brush instead — it is exactly why a good teapot is never scrubbed with soap, as we cover in our guide to Japanese teapots.
Try not to leave porous pieces soaking in the sink for hours, either. They take on water, and a waterlogged bowl is both heavier to handle and slower to dry out properly.
Drying and storing — the step most people skip
This is the habit that quietly saves earthenware. Because porous clay holds moisture, a piece put away even slightly damp can turn musty or, over weeks, grow faint mildew in the foot. Let everything air-dry fully — ideally overnight, upside down on a rack — before it is stacked into the cupboard.
When you do stack, slip a paper towel, felt pad, or soft cloth between pieces. The rough, unglazed foot ring of one bowl is precisely what scratches the glaze of the bowl beneath it. That small bit of padding is the difference between an heirloom and a shelf of scuffs.
Stains, odors, and the beauty of crazing
Many glazed pieces slowly develop kannyu (貫入) — a fine web of lines across the surface where the glaze and the clay body cooled at slightly different rates. On some wares, such as kohiki and certain celadons, it is deliberate and prized. Tea and soy gradually settle into those lines and darken them, and in Japan that slow coloring is read not as damage but as the piece earning its history.
If you would rather lift a stain, a paste of baking soda and water, left on for a while and then rinsed away, is gentle and usually enough. For odors in porous pieces, filling the bowl with dry uncooked rice overnight, or a short soak in water with a spoonful of baking soda, tends to clear them. It is best to avoid harsh bleach, which can seep into open clay and is difficult to rinse fully back out.
Dishwashers, microwaves, and heat
Sturdy, undecorated porcelain will usually survive a dishwasher, but survival is not the same as thriving. Most dishwasher damage is mechanical: pieces knock against each other and the rack, and it is the rims and foot rings that chip. The heat and strong detergent also stress glazes and fade hand-painted or gilded decoration. Washing by hand simply lets a good piece last a great deal longer.
Microwaves call for more judgment. Plain porcelain with no metallic decoration is generally fine for reheating. Earthenware and highly absorbent stoneware are riskier — moisture trapped in the clay heats unevenly and can crack a piece, sometimes without warning. Anything with gold or silver painting should never go in at all, since the metal sparks. When you cannot vouch for a piece, treat it as hand-wash and hand-warm only.
Through all of this, the enemy ceramics truly dislike is a sudden swing in temperature. Pouring boiling water into a cold cup, or setting a hot dish straight onto a cold stone counter, is what turns a hairline into a crack. Warm pieces gradually, and let hot ones cool on a trivet or a folded cloth rather than bare stone or metal.
Chips, cracks, and kintsugi
A small chip on the outside or the foot of a bowl is nothing to lose sleep over; plenty of well-loved pieces carry a few. A chip on the lip where you actually drink or eat is a different matter — the exposed edge is sharp, and on porous clay it is harder to keep clean, so it is worth retiring that piece from daily meals.
For a true break, there is kintsugi (金継ぎ) — the Japanese art of mending with lacquer and a seam of gold that treats the fracture as part of an object’s story rather than a flaw to hide. One practical caution is worth knowing before you eat from a repair: traditional kintsugi uses natural urushi lacquer and is considered food-safe once fully cured, which can take weeks. Many beginner kits sold today use epoxy or other resins and are labeled for decorative use only — lovely on a vase, but not meant for a rice bowl you eat from. Check what a kit actually contains before you trust a mended piece with food.
None of this is meant to make a bowl feel fragile. Careful habits exist for the opposite reason — so a piece can be used every day, without anxiety, for decades, long enough for the small marks of that use to become the most beautiful thing about it. That slow softening is what the Japanese mean by nagori, and it is worth the little effort that keeps it going.
Buy this, not that
Buy the felt pads before you buy another bowl. The unglazed foot ring of one piece is exactly what scratches the glaze of the piece below it, and a few cents of padding is the difference between an heirloom and a shelf of scuffs. For a bowl you actually eat from, don’t trust a repair kit without reading what is in it: traditional kintsugi uses natural urushi lacquer and is considered food-safe only once fully cured, while many beginner kits are epoxy or resin and are labelled for decorative use only. And keep hand-painted or gilded pieces out of the dishwasher — surviving a cycle is not the same as being unharmed by it.
Related reading
- A Guide to Japanese Tableware — the pieces, materials, and pottery regions at a glance.
- The Best Japanese Dinnerware Sets — how to build a table you will actually use.
- The Best Japanese Teapots (Kyusu) — why unglazed clay is never washed with soap.
- Japanese Tea: A Beginner’s Guide — matching the brew to the cup.
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