Suribachi and Oroshigane: The Two Tools That Grind and Grate

Most kitchens solve grinding and grating with one machine and one flat steel plate. A Japanese kitchen splits the job between two very old, very specific objects: a clay bowl scored inside with dense combed grooves, and a metal plate whose teeth were raised one at a time with a chisel. Neither is fast. Both do something a food processor and a box grater cannot — they control texture, which in Japanese cooking is most of the point. Here’s how to choose and keep them.

The short answer

• Suribachi: buy a 6-sun (about 18 cm) bowl first. It is the size makers themselves recommend to first-time buyers, and it covers sesame, dressings and small batches of yam without throwing food over the rim.
• Oroshigane: the teeth matter, not the metal. A hand-cut plate — copper or stainless — grates daikon into something light and fluffy. A pressed plate mashes it into water.
• Match the tool to the texture you want. Fine hand-cut teeth for wasabi and ginger, coarse for daikon, a bamboo oni-oroshi when you want shreds you can chew.
• Both die of the same thing: being put away wet. A brush in the grooves and a full dry is the whole maintenance routine.

The suribachi

What the grooves are doing

The inside of a suribachi (すり鉢) is unglazed and cut with fine radiating lines called kushime (櫛目, “comb teeth”), scored into the raw clay before firing. Against that surface a wooden pestle doesn’t just crush — it shears. Sesame seeds break open and release their oil, tofu goes from crumbly to silky, grated yam turns glossy. A blender chops at high speed and heats what it chops; the suribachi works slowly and cold, and the difference shows in aroma.

The bowl itself is an import — accounts differ on whether it reached Japan from China or by way of the Korean peninsula — and the earliest versions were smooth or only lightly scored, closer to a medicine mortar. The densely grooved bowl we now think of as the suribachi is generally credited to Bizen, the Okayama kiln town, with the modern pattern settling into place around the Edo period. Today the grooves are still carved by hand at some kilns, with a home-made iron tool worked rhythmically from the centre outward; at Tokoname the finished bowls are fired at around 1,200°C for roughly 70 hours.

You will also see the bowl sold as an atari-bachi (当たり鉢). That is superstition, not a different product: suru (“to grind”) is a homophone for losing your money, so merchants swapped in its opposite, ataru, “to hit.” The pestle becomes an ataribō, and ground sesame becomes atari-goma. If a shop lists both, they are the same thing.

Where they come from

Two names are worth knowing:

• Mino (Gifu). The centre of gravity of the modern trade is Dachi, a pottery district of Toki City in the Mino ware region. One kiln there, founded in 1910, claims about 60% of Japan’s suribachi output by its own account — if you own a plain Japanese grinding bowl, there is a fair chance it was made within a few streets of that kiln.
• Iwami (Shimane). One of the country’s suribachi specialists works at Gōtsu, in the Iwami ware district on the Sea of Japan coast — a region whose reputation was built on dense, hard-fired stoneware, and whose size chart is the one most shops quote.

Sizing it

Suribachi are sold in gō (号) or sun (寸) — treat them as the same scale, roughly 3 cm per unit of outer diameter. One specialist maker’s chart runs like this:

Size	Diameter	Suits
4-gō	about 12 cm	grinding sesame at the table, a dish for tonkatsu sauce
4.5-gō	about 13.5 cm	baby food, a small serving bowl
6-gō	about 18.5 cm	the standard first bowl — one to two people
7-gō	about 21.5 cm	two to four people; a bunch of spinach dressed in sesame
8-gō and up	25 cm and beyond	five or more, or grating yam for tororo

Two things push you larger than you expect. Grinding throws food up the walls, so a bowl that looks generous is merely adequate. And tororo — grated mountain yam — gets loosened with dashi in the same bowl, so allow for the liquid.

The pestle

The surikogi (すりこぎ) is traditionally cut from sanshō (山椒, Japanese prickly ash): a hard, wear-resistant wood, often knotty in a way that gives the hand something to hold, and long credited with keeping food from spoiling — a nice piece of lore, though it is not a substitute for washing the thing. Sanshō grows slowly and crookedly, so a genuine sanshō pestle is expensive and rarely straight; magnolia, oak and other woods are common and work fine.

A wooden pestle is not a compromise for a stone one. Wood is softer than the fired grooves, so the bowl wears the pestle rather than the pestle wearing the bowl — which is why a suribachi outlives several sticks.

Using it

1. Anchor the bowl. Set it on a damp folded cloth or a rubber mat. A suribachi that slides is a suribachi that ends up on the floor.
2. Hold the pestle with two hands — one at the top to steady and press, one lower to drive — and work with a rolling, sweeping motion around the wall of the bowl rather than pounding straight down.
3. Toast sesame first. Warm seeds in a dry pan until they start to jump and smell nutty, then grind while they’re still warm. This is the single biggest difference between homemade goma-ae and the flat version.
4. Stop early. Half-ground sesame — some seeds broken, some whole — is a texture worth having, and it is one the machine can’t give you.

Caring for it

• Soak briefly, then brush. Fill with hot water while the bowl is still dirty and let it stand a few minutes, then work a stiff natural-fibre brush across the grooves. For anything left in the channels, an old toothbrush or a bamboo sasara does it.
• Never a metal scourer. The grooves are the tool. Grinding them flat with steel ends the bowl’s usefulness.
• Dry it completely, then store it face down. The unglazed interior holds moisture, and a damp bowl in a cupboard is how a suribachi starts to smell. Dry it thoroughly — sunlight and airflow both help — and turn it over so dust stays out of the grooves.
• Wash the pestle and dry it standing. Don’t leave it soaking; wood that sits in water splits and darkens.

Some modern suribachi are rated for the dishwasher, and the base is often glazed so it won’t scratch a table. Check the maker’s marking — but even a dishwasher-safe bowl needs the brush, because a spray arm does nothing for a groove.

The oroshigane

Why the teeth are hand-cut

An oroshigane (おろし金) is not a box grater. The traditional plate is pure copper, and each tooth is raised individually with a chisel (tagane) and hammer — nothing is punched through the metal, so there are no holes, only hundreds of tiny raised blades standing at slightly different angles because a hand made them.

That irregularity is the whole trick. Uniform machine-pressed teeth crush and tear, and the daikon that comes off them is a wet, grey mush sitting in its own liquid. Hand-cut teeth sever the fibres cleanly, so the cells stay largely intact and the moisture stays inside them: the pile is pale, light, almost fluffy, and it tastes sweeter because you haven’t wrung it out.

Copper plates are then tin-plated (suzuhiki, 錫引き), which keeps the copper from tarnishing and from affecting the flavour of what you grate. The plating is soft and wears through eventually; makers generally consider a worn patch cosmetic rather than a fault. And because the teeth are cut rather than stamped, a copper plate whose teeth have gone flat can often be sent back to be re-toothed — the reason a good one is bought as a lifetime object rather than a purchase.

Choosing a material

Material	What it does	Watch for
hand-cut copper	the benchmark — sharp, irregular teeth, light and dry results; re-toothable	needs immediate drying; the priciest option
hand-cut stainless	very close to copper in results, won’t corrode, costs less	machine-pressed stainless is a different, much worse thing — check that it says hand-cut
ceramic	easy to wash, no raised teeth to trap fibre, cheap and pleasant for ginger and garlic	shallow teeth; not the tool for a big daikon
plastic	light, safe, fine for small jobs	shaves rather than cuts, so results come out watery

Most copper plates are double-sided: a coarse face for daikon, a fine face for yakumi — ginger, garlic, wasabi. Plates come in numbered sizes; larger is faster on daikon but harder to store and to wash.

Two specialist graters

• Sharkskin (samegawa oroshi) — a paddle faced with dried shark skin, whose dermal denticles act like extremely fine sandpaper. It is the traditional grater for fresh wasabi, producing a paste fine enough for the aroma to come forward instead of raw heat. Hold the rhizome upright, and turn it slowly in small circles; pressing hard makes it coarse and dulls the flavour.
• Oni-oroshi (鬼おろし) — a bamboo plate with big angled teeth, named for looking like a demon’s fangs. It doesn’t grate so much as shred: coarse, chunky daikon with real bite, good in mizore dishes and with soba. Bamboo conducts heat poorly, so the shreds don’t warm under friction. It is often described as milder than a fine grater — plausible for the pile as it sits, since the cells survive more intact, though the pungency shows up again once you chew it.

Getting daikon right

Two variables, both free:

• Which end. The upper end, near the leaves, is the sweetest and juiciest. The tail end is the sharpest. Choose by the dish — top for a mound alongside grilled fish, tail if you want heat.
• How you move. Daikon’s pungency comes from allyl isothiocyanate, which isn’t sitting there in the vegetable; it is generated when cells rupture and enzyme meets precursor. Grate gently, slowly, in circles, and less of it forms. Push hard in fast straight strokes and you make more. So: circles for mild, strokes for fierce.

Then drain, don’t wring. Tip the pile into the corner of the plate and let it shed on its own; squeezing takes the sweetness with the water.

Caring for it

The routine is short and non-negotiable, especially in copper:

1. Rinse the moment you’re done, before fibre dries in the teeth.
2. Brush lightly with a soft brush or old toothbrush and ordinary dish soap, working with the teeth rather than against them.
3. No chlorine bleach, no cleanser, no steel wool, no soaking, no dishwasher. Each one strips tin plating or flattens teeth.
4. Dry it fully and hang it, or stand it somewhere with airflow. Copper left damp in a drawer is copper that corrodes.

How to choose

If you want…	Reach for
your first grinding bowl	6-gō (about 18.5 cm) suribachi with a sanshō or hardwood pestle
sesame dressings and shira-ae for a family	7-gō, and toast the seeds first
grated yam for tororo	8-gō or larger — you’ll be adding dashi to it
the best daikon oroshi you can make at home	hand-cut copper, coarse face, gentle circles
copper results without the upkeep	hand-cut stainless
ginger and garlic, most days	a ceramic plate — small, cheap, dishwasher-tolerant
fresh wasabi	sharkskin, and slow circles
daikon with texture, for soba and hotpots	a bamboo oni-oroshi

The thread running through both tools is the same: they’re slow on purpose. The grooves and the teeth exist to break food a particular way, and that way happens to be the one that tastes best. Keep them clean, keep them dry, and neither will need replacing in your lifetime.

If the clay side of this interests you, Japanese ceramics for everyday use covers how these bodies are fired and why the unglazed ones behave differently. Or browse hand-picked, Japan-shipped tools on The Table.

Sources & Further Reading

• 道具 — すり鉢 (Tools: the Suribachi) — Washoku Japan / Japan Association for the Promotion of Traditional Japanese Cuisine (Japanese) — The association’s account of the suribachi’s transmission to Japan, the grooved form’s origin in Bizen ware, and how a Tokoname kiln carves the grooves and fires the bowls.
• すり鉢の大きさについて (On Suribachi Sizes) — Motoshige Seitōsho, Iwami ware (Japanese) — A specialist maker’s size chart in gō with diameters in centimetres, and its recommendation of 6-gō as the first bowl to buy.
• マルホン製陶所 (Maruhon Seitōsho), Dachi, Toki City (Japanese) — The Mino kiln’s own account of its 1910 founding and its roughly 60% share of Japanese suribachi production.
• 純銅製おろし金 (Pure Copper Graters) — Ōya Seisakusho (Japanese) — A copper-grater maker on raising each tooth by hand with chisel and hammer, the tin-plating step, the coarse/fine double-sided layout, and the rinse-and-dry-immediately care rule.